The dawn of the 1970s brought a new landscape to automobile manufacturing. The muscle car movement had peaked, imports continued to take market share, governmental regulations were on the rise, and the biggest new growth market was in a wave of subcompacts. Though the way forward may have been cloudy, one thing was clear: The 1960s were over.

Ford had been aggressively updating its engine lineup. Existing engines grew in displacement; the 352 grew to 390 ci, then 406, 427, and 428. A modern and compact 289 small-block replaced the obsolete 292 Y-block in 1962, and was upsized to a 302 in 1968. Also in 1968, a new big-block engine family, utilizing similar weight-reducing designs, appeared as the 429. It would be radically transformed into the Boss 429 the following year, and into the wedge-head 429 Cobra Jet for 1970. Ford’s engine development was on the move.

But while Ford had the big-block and small-block engines covered, a hole had developed. For the growing intermediate and pony car lines, the 289/302 was fine as a base engine, and the 390/428 was a great step up, but cars like the Torino had put on size and pounds compared to where the intermediate had started as the Fairlane and Comet.

For 1969, that was addressed with the introduction of the then-new 351 Windsor, but Ford’s aggressive program of modernization came up with an all-new 351 just one year after the 351 Windsor’s introduction.

In concept, the 351W was an extension of the 289/302 design, though the block was larger and not much was directly swappable. Even the firing order was different.

The new 351, nicknamed the Cleveland after Ford’s Engine Plant Number 2 where it was produced, was yet another completely new engine, from a completely new engine family they called the 335. While the 351W was obviously an extension of the 289/302, the new 351C was its own thing.

To put the new design into production, Ford spent big.

“Ford Motor Company will release this fall a brand new $100 million engine designed for the 1970s,” read an August 15, 1969, press release. “A 510,000-sqare foot addition to the company’s Cleveland Engine Plant #2 was built to produce the new 351 engine.”

1970: Meet the 351 Cleveland

Both Ford and Mercury made heavy use of the new 351. The 1970 Mercury dealer album bulleted these points to be played up to customers under the headline “Points to Emphasize about the New 351 V-8 Canted Valve Engines.”

• Computer-designed, lower and wider cylinder block made with the latest advancements in precision thin-wall casting techniques
• Compound canted valves with large heads positioned to provide maximum intake and exhaust flow capacity to provide better breathing, better flow, and permit improved cooling
• Exhaust-heated intake manifold with large oval ports to help warm up the engine quickly and recycle more heat to the engine when needed
• Lightweight pistons with large valve clearance cutout for the intake valve that improve breathing and permit a bigger charge of the fuel-air mixture into cylinders
• Five main bearing nodular iron crankshaft making possible stronger, leaner crankshafts that weigh less

Bore and stroke were the same on the 351W and 351C, though the block was completely different. A quick way to tell the two apart is that the 351C has the water pump housing cast into the block, while the 351W block is flat at the front.

The biggest changes were in the heads, which, save for the water jacket openings, were verbatim pickups of the Boss 302 heads introduced in 1969. The heads had a lot in common with the heads introduced on the 429 in 1968. Initially, two different castings were used: 351Cs with two-barrel carbs had big ports and valves, while 351Cs with four-barrel carbs had huge ports and valves. Two-barrel engines got 2.04/1.65-inch valves, intake/exhaust, and four-barrel engines got 2.19/1.71-inch valves. For perspective, 2.19 is also the size of intake valves on Chevrolet’s revered 427 L88. Intake and exhaust ports were also substantially larger in the four-barrel engine.

Another key upgrade was the operating angle of the 351C’s valves. Instead of having all the valves aligned in the same plane, as with the 351W, the 351C tilted the valves slightly. From the cylinder centerline, intake valves leaned around 9 degrees toward the intake port and around 4 degrees to the side. This allowed for slightly larger valve diameter and smoother bends in the port contours. Because each cylinder’s valves operated at different angles, each valve had its own pedestal.

Cams for both engines were hydraulic, and the four-barrel cam was slightly hotter than the two-barrel.

Airflow through the heads was a quantum leap forward from Ford’s traditional smallish ports, though the four-barrel heads and valves may have been too much of a good thing, at least for responsive street performance. NASCAR engine builders improved port efficiency by using epoxy to raise the port floor and reduce the opening of both intake and exhaust ports by around 30 percent.

Other four-barrel upgrades over the two-barrel engines were stainless steel head gaskets, higher valve lift (an increase of 0.025-inch intake/exhaust), a different combustion chamber with quench area yielding an 11.0:1 compression ratio, and dual exhaust. Horsepower ratings were 250 at 4,600 rpm for the two-barrel, and 300 at 5,400 rpm for the four-barrel, 10 more than the 1969 351W four-barrel. Interestingly, the 351C four-barrel’s rated torque output of 380 at 3,400 rpm was down from the 351W four-barrel’s rating of 385 at 3,200.

The 351C found lots of applications, including an intermediate engine option on many base models, as well as being the standard engine on step-up models like Mach 1 and Cougar XR7.

Road tests of the day showed 351C four-barrel Mach 1 Mustangs running 15.2 e.t.’s, about a tenth or two quicker than a similar 351W Mach 1 from a year earlier.

1971: Cleveland Goes Boss

Like the 429, which got the performance treatment after first appearing as a passenger car engine, the 351 had a hot new version for 1971. Original plans were to continue the Boss 302 into 1971, but that was scratched in the last stages of development. Likewise, the Boss 429 was dropped. The 429 Cobra Jet and 429 Cobra Jet Ram Air replaced the 428 Cobra Jet as the top engine option for 1971, but the only Boss Mustang offered would be the Boss 351, built and badged around the new 351C engine.

Available beginning in November 1970, the Boss 351 carried very little forward from earlier Boss Mustangs. The body was completely new, and the amped-up new 351 was, too.

Starting with the already-strong 351C four-barrel, engineers gave the engine generous upgrades, adding four-bolt mains to the block and upgrading the pistons to forged aluminum. The crank remained cast nodular iron and the rods remained forged, though both ends of the crank were upgraded with a flywheel cast of high nodular iron at the rear and a larger balancer at the front.

Ports and valve size were unchanged from the 1970 351C, though the valvetrain was extensively upgraded in ways that might escape the casual glance, starting with a hotter mechanical-lifter cam with higher lift and extended duration. Pushrods were the same length as standard production 351s, but were hardened and ground, and kept in place with guide plates. Stronger valve springs had 315 pounds of pressure open, up from the 285 pounds for non-Boss 351 engines, and they got a stamped steel seat to prevent them from wandering at high rpm. Boss 351 heads were machined for threaded 7/16-inch rocker pedestals (production 351s used pressed-in 5/16 studs), and the valves were fitted with hardened, single-groove valve keepers.

The Boss 351 intake was cast aluminum and featured a spread-bore pattern. The carburetor looked like any other Autolite 4300, but the Boss used a 4300-D with the spread-bore pattern—smaller primaries and larger secondaries. All Boss 351s came with ram air induction, comprised of an open-element breather mated to functional, dual-inlet hoodscoops. Exhaust manifolds, having been designed well in the first place, were standard 351 production.

Elsewhere, electronic ignition was still to come, so a standard dual-point distributor provided improved ignition. Alternators had oversized pulleys to prevent overspeed.

Factory rated at 330 hp at 5,400 rpm, this new engine was the highest output that this engine family would see. Other 351 performance engines would follow, but none would match the Boss 351. In Ford’s advance press materials it was called the 351 H.O., though in other Ford lit it is referred to as the Boss 351, which it has come to be known today.

1971: 351 Cobra Jet

Now things get confusing. In May 1971, a third version of the 351 four-barrel appeared, called the 351 Cobra Jet. It was, in essence, a warmed-over 351 four-barrel, but with lower-compression (9.0:1), open-chamber heads, and only a few of the Boss 351’s goodies: four-bolt mains, a slightly upgraded hydraulic-lifter cam (0.480/0.488-inch lift and 270/290 degrees duration intake/exhaust), dual-point distributor, and the Autolite spread-bore 4300-D carburetor. The rest of the engine was standard 351 four-barrel.

1972: Hey, Let’s Change Things Again

As if the waters weren’t muddy enough, 1972 brought yet another shuffling of the 351 landscape. The 351 Cobra Jet was gone, at least in name. The 1972 351 four-barrel engine had all the same specs as 1971’s 351 Cobra Jet, but it was no longer called a Cobra Jet, at least by Ford. (Mercury literature retains the CJ reference.) The lone difference is that the 1972 version’s cam was retarded 4 degrees. Horsepower rating for this engine was 266 at 5,400, and torque was 301 at 3,600.

The Boss 351 engine shared a similar fate. The Boss 351 Mustang was dropped, but the Boss 351 engine was carried over mostly intact, only under the 351 H.O. name. Or was it a different name? After all, Ford called the Boss 351 engine the 351 H.O. in most of its press materials.

While the 1972 351 H.O. retained most all of the Boss 351’s superb hardware, three key revisions had a big impact on the engine’s output. The heads with the large ports and valves were retained, and so were the mechanical lifters and valvetrain, but the new heads had the larger, open combustion chamber. That, with new flat-top pistons, dropped the compression ratio 2.5 points to 8.8:1. Ford also dialed back cam duration from 290 degrees to 275. Horsepower fell 55, from 330 to 275, and torque plunged 84 lb-ft, from 380 to 286. Even though 1972 ratings were net, this was a sharp detune. More cuts were on the way.

For the record, Ford also introduced the 400 two-barrel in 1972, a higher-displacement (half-inch longer stroke) but low-revving, low-octane, low-compression, low-performance spinoff of the 351. It had a taller block to accommodate the longer stroke, but there was never a performance version of the 400.

Because of the move to net horsepower standards, ratings changed by car. The November 11, 1972, Lincoln-Mercury Product News Bulletin explained: “…the new rating procedure results in minor power rating differences when the same engine is used in different car lines. For example the 351-2V engine has a different horsepower rating for Mercury, Montego and Cougar. This is caused by differences in the exhaust, air intake and emission control systems. NOTE: All ratings are for engines equipped to meet the California emission standards. There are slight variances where the California equipment is not installed.”

Decoded, that means that the published horsepower figures are a worst-case scenario, and cars without California emissions will have a bit more power.

1973-1974: Winding Down

For 1973, the Boss 351 and 351 H.O. were both canceled, leaving a single revised version of the 351 Cobra Jet as the only remaining performance 351. The term Cobra Jet was not used in Ford marketing, but did show up in Ford’s 1973 AMA Specifications for Mustang, and in service manuals, perhaps out of momentum.

Heads were the large-port four-barrel castings, but were now fitted with smaller, 2.04-inch intake and 1.65-inch exhaust valves.

The 1973 Ford Car Facts dealer album mentioned these highlights:

• exceptionally wide four-bolt main bearing caps and 1/2-inch bolts
• high lift cam
• large capacity 4300-D carburetor and special intake manifold
• special valve springs
• large inertia member vibration camper

Horsepower and torque specs were unpublished in both the 1973 and 1974 Ford Car Facts dealer albums. There were almost two pages of discussion about emissions systems, but not a single line about horsepower and torque, save for this note in the section on Power Teams: “Engine compression ratios, horsepower and torque data to be furnished at a later date.”

By 1974, performance was over. Mustang was forging ahead as a radically downsized compact with an inline four-cylinder as its standard powerplant.

The Cleveland design would continue, but as the long-stroke 351M and 400. For fans of classic, high-powered muscle, the best years of the Cleveland design had come and gone.

Pinnacle of the 351 Cleveland engine design: the 1971 351 four-barrel H.O., better known in enthusiast circles as the Boss 351 engine. All the good stuff is here: four-bolt mains, giant ports and valves, high-compression combustion chambers, forged pistons, aluminum intake, and Ram Air.

The 351 story begins with the 1969 351 Windsor, a tall-deck spinoff of the world-beating 289/302. It featured a half-inch longer stroke than the 302, and even in standard passenger car form (there was no performance version of the 351W) it equaled the Boss 302’s factory horsepower rating. This image is taken from the 1969 press event where the 351W engine was introduced. Can you spot the error?

Mid-1970, the new 351 Cleveland replaced the 351 Windsor. The 351 Cleveland featured many advancements, especially in the cylinder heads, which were patterned after the 429. Ports were huge, with valves to match. The 351C block is easily distinguished by the cast-in timing gear cover that extends forward at the front of the engine.

Expanding on the valvetrain geometry introduced on the 1968 429, the Cleveland’s improved breathing came from canted valves. Both intake and exhaust valves were tilted on two different planes, allowing large diameters, smoother port transitions, and greater flow of coolant between the valves.

Connecting rods on 351C engines, both two- and four-barrel versions, were forged steel. Main bearing caps for both had extended width to allow for the possibility of four-bolt mains. Neither engine had four-bolt mains for 1970, but beginning in 1971 they would become standard on four-barrel 351C engines.

Two versions of the 351C were built for 1970, a two-barrel engine and a four-barrel. On the 351C, the difference extended beyond the carb and intake manifold. Two-barrel 351s had heads with large ports and valves, while four-barrel 351s got very large ports and valves, and a 600-cfm Autolite 4300-A carburetor on an iron, dual-plane intake manifold. Cleveland heads have “2” or “4” cast into the corners to designate which head it is.

Popup pistons and closed-chamber heads helped bump compression up to 11.0:1 for the 1970 351C four-barrel and 1971 351 H.O. (Boss 351). All 351 production heads were iron. No aluminum option was offered. The 2.19-inch intake valves were the largest in the industry for a midsized engine. For comparison, the 1970 1/2 Z28’s LT-1 engine used 2.02-inch intake valves.

To better tolerate lower octane fuels, all 1972 and later 351Cs used the lower compression, open-chamber heads. Valve size remained the same for 1972, but changes were coming for 1973 and beyond.

The 1971 and 1972 351 H.O. engines got many valvetrain upgrades, including: larger-diameter, threaded rocker studs; hardened pushrods; guide plates; hardened, single-groove valve keepers; higher-rate valve springs; steel spring base; and hotter, solid-lifter cam. These changes, teamed with the Cleveland’s ample ports and valves, really gave the Boss 351 a mean streak.

Exhaust manifolds, long a bottleneck on Ford engines, were addressed on the 351C. These castings may not have flowed as well as the 427’s long-tube manifolds, but they were a big improvement over the 289 and 390 manifolds. Four-barrel 351 exhaust manifolds had larger ports and passages than the two-barrel castings, but both had 2.0-inch outlets. The exception were Boss 351 manifolds, which had larger 2.25-inch outlets.

You can tell a 351 Cleveland engine at a glance by its rectangular valve covers. Like the 289/302 predecessors, 351 Windsor heads have a little angle at the front and rear of the valve covers. Ford invested more than $100 million to bring the 351C to the market, and while it added a bright spot to the automaker’s engine lineup early in the 1970s, it closed out the decade as an unimpressive, long-stroke 351M and 400 two-barrel.

The post Everything You Need to Know About Ford’s 351 Cleveland Powerhouse Powerplant appeared first on Hot Rod Magazine.

What gearhead doesn’t dream of having a Hemi-powered muscle machine? Like you, I’ve shared that dream since childhood. It all started by going for a ride in a ’69 Hemi Road Runner back in the spring of 1970. At that impressionable age of 12, I was hooked with Hemi fever. This green Hemi car was owned by my neighbor’s brother-in-law. He told us the 383 hood inserts were in place to bait and then waste the unsuspecting on the street. After our ride he showed me the engine with the plug wires going through the center of valve covers. I was hooked.

What makes the Hemi so great is its cool-looking head design that makes efficient power. That’s why in today’s world when you look under a hood, you’ll likely see a Hemi head design. The hemispherically shaped combustion chamber with the opposed-angle position of the valves lends itself to the best flow and combustion efficiency of any cylinder head design. Fortunately for us Hemi lovers, Chrysler began experimenting with hemispherical cylinder head designs back in the 1940s during the war. They found out it was the most efficient cylinder head design for pushing more air in and out of an engine, because it made the most power without increasing displacement. The Hemi legend began in the 1950s, and it is still going strong today with the new Gen III Hemi.

Now it’s the 50th anniversary of the 426 Street Hemi, and with as many years in technological engine advancements, now was a great time for me to build my dream: a brutal pump-gas Street Hemi. The Mopar foundry making the Hemi block casting was closed for a few years, causing it to be difficult to obtain a block. Recently, the foundry reopened and is currently producing new beefier cast-iron Gen II Hemi blocks. Plus, Edelbrock is making the latest improved edition of the Hemi cylinder head (Victor Jr.). At that, I knew I better get a new Hemi bare block and begin a 528ci Street Hemi buildup. First we’ll start by modifying a set of the new Edelbrock Hemi heads with renowned Hemi engine expert Ray Barton, the man who practically reinvented the Hemi. Barton-built Hemis have been setting NHRA, land-speed, and other racing records for decades, keeping the Hemi on top for over 40 years.

The new Edelbrock Victor Jr. Hemi heads we’re using here are available directly from Edelbrock or any of its dealers, like Ray Barton Racing Engines (RBRE). They flow over 400 cfm out of the box and feature 245cc stock-size intake runners, making for excellent port velocity and street performance. They’re an easy bolt-on replacement for the stock Gen II Hemi while offering big gains over the original units. Part numbers 61175 and 61179 ($1,426 street price, each) are complete and ready to run with cam lifts under .700-inch lift. The 61169 is for those planning to run a solid camshaft or one with more than .700-inch lift. This head only requires the springs, seals, retainers, and locks to match your cam choice.

Follow along to see how we prepare Edelbrock’s new Hemi heads for our Barton-built 528 Street Hemi. The port work and valve job is a service available from RBRE. Check out the Ray Barton website and the Street Series 528 Hemi crate engines available to order.

The post Port Edelbrock’s Hemi Head For 38 More CFM! appeared first on Hot Rod Magazine.

For those that aren’t familiar, Fuel Air Spark Technology–or FAST as most people know the company–has been innovating with high performance ignitions, engine controls and other components for fuel injected engines.

Of course, that doesn’t do much good for stock car racers who need a traditional distributor, coil and CD ignition. That’s changed, however, when FAST recently expanded its lineup of ignition products to include components made specifically for circle track racers.

FAST’s new Race Billet distributor is designed to be a full-race distributor with high timing precision all the way through the upper rpm ranges where race engines live–while still being affordable to the average racer. Unlike most distributors on the market, the Race Billet doesn’t use a magnetic trigger. Instead, it utilizes a spinning disc with eight metered “windows” evenly spaced. A light beam is angled to pass through the windows, and when the light beam is broken the system knows to send a spark to the correct cylinder. It’s called an optical trigger, and it literally works at the speed of light.

Besides the optical trigger setup, the Race Billet distributor eliminates the mechanical advance instead of simply locking it out, which greatly simplifies the system. The housings are cut from billet aluminum, while the shaft is stainless steel and supported by bearings at both the top and bottom for precise movement lap after lap.

To go with it FAST has also introduced its E6 capacitive discharge ignition, which is fully epoxied to work both in dirt and asphalt racing environments. We’re also told it mates ideally with the Race Billet distributor. For example, since the distributor has no mechanical ability to advance or retard the timing, the E6 ignition box actually has a start retard programmed in. It works by retarding the timing 20 degrees when the car is first fired up and brings the timing back up to full advance before the engine reaches one thousand rpm. The idea is the timing retard makes a high compression engine much easier to re-fire after it’s hot. There’s also a dial-in rev limiter that operates in 100 rpm increments.

When we heard about FAST’s new ignition components for racers we have to admit we were intrigued. So we asked FAST to send over a complete ignition system setup and took it over to Keith Dorton of Automotive Specialists in Concord, NC, to put it to the test.

And we didn’t pick Dorton’s shop randomly for the test. Besides being one of the top engine builders in Circle Track racing, Dorton is a big believer in doing proper R&D on all his engine packages. In order to be able to see exactly what the ignition is doing, he has invested in equipment that allows him to track the actual ignition timing in all eight cylinders during a dyno pull.

Normally, most racers will set their ignition timing with a timing light attached to the plug wire going to the first cylinder and call it a day. But that only tells you the timing in that particular cylinder, and it’s only as accurate as the timing pointer, the scale on the balancer and your naked eye. But you have no idea what the actual spark timing is in the other seven cylinders, and that ignorance can be costing you power. Dorton’s system actually tracks spark timing within one-tenth of one degree, in every cylinder every 100 rpm step across an entire dyno pull. It’s quite impressive and really reveals how an ignition system is actually performing.

For a test engine, we chose a Chevrolet small block that will be racing in the Late Model Stock class. We thought this would be a perfect option because we’re dealing with a typical timing chain roller set, and stock harmonic damper which sends lots more harmonics through the cam and distributor gear than a timing belt and race quality ATI damper. We’re also fighting against as-cast iron heads and a two barrel carb, so every bit of power we can make is critical here.

The post FAST Firepower appeared first on Hot Rod Magazine.

If you’ve been around the world of performance engines for any length of time, you know things don’t always go as planned. Such was the case with the block used in this engine build. It was damaged enough to need new cylinder liners and have it’s crank ground. The owner brought it to John Bouchard Engines, in Hendersonville, Tennessee, with a simple request, “Make big power, and make it last.”

Likewise, engine builder John Bouchard turned to the experienced hands at Tommy’s Auto Machine for the extensive machine work, which included re-sleeving the LS7 block with Darton sleeves and a balancing the rotating assembly. Their hard work was rewarded with 716 horsepower and 637 lb-ft of torque on pump gas. Follow along as the guys repair this buggered-up block and hit the jackpot by making serious power along the way.

In order to install Darton’s 4.125-inch bore sleeves in the LS7 block, Frank Ofria at Tommy’s Auto Machine, of Springfield, Tennessee, warmed the block to about 350 degrees to loosen the block’s grip on the OEM iron sleeves.

With the block up to temperature, some of the sleeves slid right out, but others needed a few taps with a drift to drive them out.

Since the Darton sleeves were donated from another used block, John Bouchard measured their outside diameter in several places to check for roundness. Bouchard said reused sleeves will often distort and may need to be bored oversized to straighten them out.

Tommy’s Machine bored the block as needed to set the correct interference fit between the block and sleeves.

After boring, the final diameter was reached with the cylinder hone.

After honing, Bouchard put the block back in the oven and the sleeves in the freezer. The difference in temperature allows the sleeves to slip easily into the block.

Working quickly but carefully, Ofria slid the frozen sleeves into the heated engine block. When the block and the sleeves reached the same temperature, the sleeves had the proper interference fit to keep them in place.

After the block cooled back to room temperature, Bouchard skimmed the cylinder deck to create a new, flat sealing surface.

With torque plates installed to simulate the clamping load of the cylinder head, Bouchard honed the cylinders to their final diameter of 4.130-inch.

Bouchard ground off the sharp edges at the top of the cylinders with a cone-shaped abrasive pad. This helps prevent damage to the rings when the pistons are installed.

To ensure the connecting rod bolts wouldn’t hit the new sleeves, Bouchard used a carbide bit to clearance the bottom of the cylinders in the same location as the factory sleeves had been.

Next, Bouchard installed new cam bearings, making sure the oil passage holes lined up correctly. Then, he test-fit the camshaft.

Tommy’s Auto Machine recommends balancing all high-performance engines. Bouchard begins the process by weighing the big- and small-ends of each of the Lunati H-beam connecting rods.

The Wiseco Pro-True pistons were plopped on the scale next, followed by the piston rings. The combined weight of the rods, pistons, and rings are added together, with a few grams extra to account for the weight of any oil on the parts as the engine is running.

To equalize the reciprocating weight, Bouchard removed material from the small end of each connecting rod where necessary. The big ends were within spec.

Since this engine was destined for a 1998 Trans Am, the crank needed a 24-tooth crank trigger wheel. Ofria welded the crank trigger wheel together to ensure it wouldn’t separate. Tommy’s Auto Machine does this with all their 24-tooth LS-based engine builds.

Bouchard installed the welded trigger wheel onto the Lunati crankshaft using a special fixture from Goodson Tools. It indexes the wheel in the correct position on the crank. Bouchard warned, “This is important. If you don’t do this, the engine won’t fire up.”

Ofria checked the balance of the crank with the flywheel installed.

The balancing machine indicated weight needed to be removed from an area on the crankshaft without a counterweight. The next best solution was to remove weight from the flywheel. Bouchard explained, “Using the flywheel for balance isn’t ideal, but sometimes you don’t have a choice if you want perfect balance.”

To move a heavy spot on the nose of the crankshaft, Ofria filled one of the balance holes previously drilled in the crankshaft.

Ofria finished the crankshaft work by polishing the journals and washing it thoroughly before final assembly.

Bouchard checked the main bearings’ journal diameters. This used Lunati crankshaft was reground 0.01-inch undersized on the main and rod journals to clean up the surfaces from the customer’s previous failure.

To calculate bearing clearance, Bouchard measured the inside diameter of the main bearing caps. Bouchard verified a 0.0025-inch to 0.002inch bearing clearance on this build.

After similarly measuring the inside diameter of the connecting rods, Bouchard honed the rods to size for the clearance he wanted.

The Wiseco pistons were shipped with a file-fit ring pack. Bouchard set the top ring gap to 0.0XX-inch and the second rings to 0.02X0-inch, verifying his work with a feeler gauge.

With the ring gaps set, Bouchard carefully assembled the rotating assembly.

Being a naturally aspirated build, maximizing air flow through the cylinder heads is critical. To this end, Bouchard chose a set of CNC-ported Precision Race Components LS7 heads, manufactured by Texas Speed & Performance. With 285cc intake runners, 2.250 / 1.160-inch valves, these heads have the potential to flow more than 380-cfm at 0.600-inch lift.

These were used cylinder heads that Bouchard rebuilt with new springs and retainers from Comp. With the ARP studs torqued in place, Bouchard checked the valvetrain geometry and ordered custom pushrods from Trick Flow Specialties. He reused the original GM lifters.

Bouchard set the engine up on Tommy’s Superflow dyno with a Mast Motorsports CNC-ported LS7 intake manifold, a Demon 4500-style carburetor, an MSD ignition, and 1-3/4-inch dyno headers.

Running 93-octane pump gas and 26 degrees of total ignition timing, the 429 ci engine pumped out an impressive 716 horsepower at 6,500 rpm, and a tire-shredding 637 lb-ft of torque at 5,000 rpm.

The post Build 700 hp Out of a Broken Engine Block appeared first on Hot Rod Magazine.

What’s better than having a Hemi under your hood? Having one that’s free! That’s right, a ground-pounding 572 Hemi will be raffled off at this year’s Carlisle Chrysler Nationals (www.carlisleevents.com). What’s the catch? Nothing. Just sign up and you could take this mighty elephant home with you.

Mopar faithful have been flocking to this awesome event for decades, and this year’s event will take place July 15-17. You can check out the engine at the show, as our friends at Muscle Motors will be firing this baby up every hour to wake up the troops. Heck, the local municipality might actually declare an earthquake when the ground shakes under this mighty Hemi.

If you’ve been following our buildup of the Carlisle Chrysler Nationals Street Hemi giveaway motor, we last went over the short-block build details of this mighty mastodon. Now it’s time to begin bolting the top-half of the Hemi together, and we’re going to give you the lowdown on the combination.

Our goal is to push the needle on the dyno way past 700 hp—all on pump gas. To achieve that, Mopar engine-building guru Mike Ware at Muscle Motors (musclemotorsracing.com) made sure to source the right parts before the build. He’s been assembling some pretty potent Mopar engines for over 28 years and knows how to extract every ounce of power from an engine, especially from pump-gas motors.

“All the pieces fell in place this year to give away this thumping torque monster. We’re excited to again be working on another engine that some lucky enthusiast will win,” says Mike Ware from Muscle Motors. “Every part we chose for the build came off the shelf, and there’s really nothing exotic about this 572 Hemi. This engine will have great street manners but when you step on the throttle, it’ll snap your head back,” added Mike.

Cylinder Heads
When it came time to achieve the 700-plus horsepower and torque levels out of a 93-octane naturally aspirated engine, the first order of business was getting a pair of heads that could flow the mass quantities of air Muscle Motors needed. The guys looked at some cylinder head flow numbers from their prior builds and knew how much cfm was needed, and in what rpm range it would reach the target power levels.

That’s when they enlisted their friends Edelbrock for a set of their beautifully sculpted Victor Junior CNC Hemi heads (PN 61175). These Hemi heads are truly a work of art and something to behold. It seems like yesterday that finding a good, reasonably priced set of Hemi aluminum heads for a street car (that weren’t beat up) was pure fantasy. Now, Edelbrock has worked their magic and these heads have all the best stuff we could ever ask for. Check this out: fully CNC’d combustion chambers and blended seats, revised exhaust valve angles to accommodate larger intake valves, and brass tubes installed in exhaust pushrod holes to allow maximum clearance with minimal port intrusion.

“Edelbrock really improved the head over the stock units by putting a bigger intake valve in it. What really makes these new Hemi heads killer is the intake runner volume is 245 cc so basically cast the head ported. Out of the box, these heads will flow right around 440 cfm. That’s pretty stout for a stock-style ported head,” noted Mike.

There are also more improvements in the Edelbrock head that enhance airflow. “Edelbrock did something in the chamber. They have a raised hump in between the intake and exhaust valve to help slow the airflow in head when you have a lot of overlap in the camshaft. That’s when the exhaust valve is just closing and the intake valve is opening and therefore both valves are open for a short period of time. The air/fuel charge will sometimes go from the intake right up the exhaust port prematurely. So the engineers at Edelbrock put the crossflow hump in the middle of the chamber to help slow that down and increase performance.”

The new Edelbrock Victor Junior Hemi heads also have the exhaust valve tipped 2 degrees to get it out of the way because of the bigger 2.32-inch intake valve.

Intake Manifold
To keep with the Street Hemi vibe of a 2×4 setup, Mike chose the Indy Mod Man Hemi intake. Even though he has factory inline dual-plane intakes laying around the shop, Mike knew it would be struggling to move enough air for an engine of this size.

Another reason the Indy Mod Man intake was chosen was its height consideration. The Hemi Mod Man is actually slightly shorter that the factory Hemi piece, and with different tops it can accept the bolt pattern for the FAST’s EZ throttle bodies. One of Mike’s goals was to make sure this 572 would fit under the stock hood of most production Mopars. “I didn’t want whoever wins this 572 Hemi to go through the hassles of cutting up his hood or buying a fiberglass replacement with a scoop just to get this engine in their car,” explained Mike.

Fuel Injection
We’ve all heard stories, or maybe have lived them, on how multiple-carb setups can be a hassle on the street. Everything from poor starting to running rich at idle seems to be a common problem that’s aggravated even more with today’s pump gas. That’s why Mike went with a FAST EFI system to bring this Street Hemi into the 21st century.

Muscle Motors is using a pair of FAST EZ throttle bodies each moving around 1,000 cfm, enough to provide plenty of air to feed 572 cubic inches of Hemi. This will be more than enough to support the projected power of the engine while giving it great part throttle respond, easy cold start, and all those other wonderful things fuel injection does exceptionally well.

With twin throttle bodies, it pays homage to the original 426 Street Hemi, yet will be more livable in modern times. The rest of the FAST EZ EFI system is an installer’s dream with their distributor, harness, ignition box, and coils, so everything is plug and play.

So, have we tempted you enough? If so, just head over to www.carlisleevents.com and register to win this beast!

For Part 1 of the series, click here!

The post Win This Hemi! Part 2: How To Feed a 572ci Street Hemi appeared first on Hot Rod Magazine.

We have been engrossed in electronic fuel injection for more than 30 years, which makes it challenging to remember the humble two- and four-throat carburetor. Fox-body Mustangs were fitted with carbureted fuel systems from 1979 to 1985. When Ford gave the Mustang GT that first shot of adrenaline in 1983 with the first four-barrel carbureted pony in a decade, it looked to Holley for inspiration. Holley, as it had done many times in the past, stepped up with just the kind of carburetor Ford wanted.

The Holley 4180C four-barrel carburetor was originally factory installed on all 1983-1985 Mustangs equipped with the 5.0L High Output engine and manual transmission. Models with Automatic Overdrive got CFI (central fuel injection), which was fired by EEC-III or EEC-IV depending upon build date. The 5.0L-4V was GT only in 1983-1984, then also LX models for 1985.

Although the Holley 4180C resembled and performed like the more traditional Holley 4150/4160/1850 carburetors it was decidedly different than those high-performance atomizers. The 4180C was a Ford- and Holley-engineered carburetor manufactured by Holley for Ford production vehicles like the Mustang and even F-Series trucks.

When you pop the twin-snorkle air cleaner on one of these Fox classics, the 4180C’s looks can be quite deceiving because it looks like a traditional Holley. However, the 4180C employs a different main metering system and idle circuit. Ford and Holley designed this guy to be tamperproof, with sealed idle mixture screws along with annular discharge boosters over the primary throttle plates. The primary metering block has very little in common with those we find on the 4150/4160/1850 series carburetors. And if you’re thinking about swapping a Holley primary metering block into your 4180C, forget it. They do not interchange. The main body will not accommodate a typical Holley metering block.

If there’s any good news to be found, it’s that the 4180C’s secondary side will accommodate the 4160’s metering plate or 4150’s metering block with minor modifications. You can even use Holley cathedral or Le Mans–style fuel bowls on the 4180C depending upon your local smog laws. Before taking a leap into the deep end of the pool you must first decide whether any modifications make sense on your 4180C, especially if you live in an area with tough emissions testing laws. We are also of the belief that most smog shops wouldn’t know the difference between a box-stock 4180C and a modified piece on a visual unless your 5.0L Mustang fails the tailpipe sniffer test.

Upon examination of the baseplate we learn idle mixture screws are in a different location from what you see with traditional Holleys. Instead of being in the primary metering block, idle mixture screws are in the baseplate accompanied by tamperproof block-off plugs. These plugs can be removed carefully to gain access to the Allen-head idle mixture screws if it’s that important to you. The electric choke is factory preset and really does not require adjustment. The 4180C’s primary metering block is fitted with close-limit main metering jets.

The 4180C accelerator pump package is virtually the same as the 4150/4160/1850 with complete interchangeability. When you carefully evaluate the 4180C carburetor, you find it is a reliable atomizer that delivers predictable performance because it enjoys the reliability of Ford’s extensive testing and engineering coupled with Holley’s expertise. This what makes the 4180C a factory performance carburetor you can trust as long as you can find a good core. That is why it is suggested you keep modifications to a minimum to both pass the toughest smog check while yielding the performance you desire.

1. The 4180C is fitted with a dual-snorkel air cleaner, which debuted in 1982 when the 5.0L High Output small-block was introduced. The 1982 dual-snorkel air cleaner was smaller and parked atop a Motorcraft 2150 two-barrel carburetor. When four-barrel 4180C carburetion arrived for 1983 Ford went to a larger twin-snorkel air cleaner used through 1985.

2. The 4180C was surely a smog carburetor with evaporative emissions plumbing and a host of other low-emissions features. What the 4180C has going for it is reliable, predictable performance you can live with, especially if you’re driving a stocker. Durability comes from OEM-level engineering and testing.

3. From this side you can see the California emissions vacuum choke pull-off, which does not appear on 49-state 4180C carburetors. The choke pull-off opens the choke in less time to reduce cold emissions startup. This is an electric choke, which was conceived for the same reason: more reliable cold start, quick pull-off, and lower emissions.

4. With the 4180C removed we get a closer look at the carb spacer and EGR (exhaust gas recirculation) package. There is also a heat shield to keep excessive engine heat away from the fuel bowls.

5. It is a good idea to periodically remove the carb/EGR spacer and clean the passages. If you are having idle quality issues check the EGR valve, which can stick open due to excessive carbon deposits. Make sure the EGR is getting adequate vacuum for proper function. Function happens when you modulate the throttle.

6. This restored Holley 4180C built by Pony Carburetors has been out of business for many years as a result of its founder’s passing, the late great Jon Enyart. These folks did incredible carburetor restorations and tuning. Enyart was well known for his tuning clinics and exceptional restorations.

7. This is the fast idle solenoid, which increases idle speed when the air conditioning compressor clutch engages. There’s also a hot-idle compensator, which creates a vacuum leak to increase idle speed when engine temperature increases. In theory, the hot idle compensator keeps engine temperature stable.

8. The annular discharge boosters in the primaries are one distinct difference between the traditional performance Holley 4150/4160/1850 carburetors and the 4180C.

9. Although the 4180C baseplate is similar to the traditional Holley, it is a completely different piece with sealed Allen-head idle mixture screws, which are normally in the primary metering block on a Holley.

10. The 4180C baseplate shares nothing in common with Holley off-the-shelf carburetors because it is fitted with sealed tamperproof idle mixture screws. This core has had its tamperproof plugs removed for idle mixture screw access. An Allen wrench is used to tweak idle mixture on the 4180C.

11. Here’s a 49-state 4180C. It does not have the California-inspired choke vacuum pull-off. This 4180C core has been rebuilt, hence the electric choke cap screws and damaged screw heads. These electric chokes were originally tamperproof and had screws you could not remove.

12. A closer look at the California emissions vacuum choke pull-off and electric choke.

13. The 4180C primary metering block with its close-limit jets and power valve. When you compare the 4180C metering block with that of a 4150/4160/1850 you see they are different and not interchangeable. However, this metering block will accommodate Holley main metering jets.

14. This is a 4150/4160/1850 primary metering block. Do you see the differences?

15. Here is the backside of the 4180C primary metering block with two-stage power valve.

16. This is the traditional 4150/4160/1850 primary metering block.

17. The 4180C sports brass floats. You can swap in cathedral or Le Mans float bowls if you are considering canyon cutting or some form of competition.

18. The Holley 4180C carburetor will be stamped with a Ford part number along with a Holley list number. If it does not have a Ford part number it is not a 4180C.

19. Off-the-shelf Holleys will have the list number only.

20. MCE Engines in Los Angeles strongly suggests K&N’s Stub Stack for more streamlined airflow. The Stub Stack is dyno proven to improve power. It works.

21. Carburetor spacers do improve horsepower and torque. However, we suggest sticking with the factory EGR carb spacer, which is effective and will pass a smog check.

The post For 3 Years the 5.0L High Output Was Fitted With the Holley 4180C Carburetor appeared first on Hot Rod Magazine.

Yeah, we know—why bother with a 4.8? It’s not a 6.0L. Newsflash: Not everybody wants or needs a 6.0L LS engine. If that’s true, then why a 4.8? It’s only 293 ci. Our counter to that: Car Craft bought a complete LS engine including the accessory drive, intake, and coils for $200. We bolted in a cam, carbureted intake, and headers, and it made 383 hp (1.3 hp/ci). True, our little motor doesn’t make as much torque as its heftier cousins. But a 4.8L delivers dirt-cheap LS power. When we pumped it up with a set of ported heads, we saw 432 hp, but we’re getting ahead of the story.

The scenario looks like this. Your magazine-fed ego demands an LS7 or LS3 for your 1988 G-body. But reality quickly delivers that proverbial boot to the head when you realize your PBR beer budget can’t even afford a hammered 6.0L, so most guys do nothing. Where’s the fun in that? Here’s where you have to get car craftier.

Find a cheap 4.8L and do the LS swap. Spend the important dollars on the intake, ignition, headers, and oil pan that complete the swap. If you have enough coin left over, you can add a small cam and valvesprings. All of these parts will bolt right on any LS engine as long as it has a 24x crank and cathedral-port heads. This gives you a head start on the project without spending big money up front. We’ve run across 4.8L long-blocks as cheap as $100. At this point, the engine is the cheapest item on the list!

Our example started in a familiar way. The engine we bought was advertised as a 5.3L back when we didn’t know how to tell the difference. Our engine had flat-top pistons—a dead giveaway for a 4.8L. For the record, 5.3L motors use the same heads but come with dished pistons. A cheap bore scope from Harbor Freight is a good way to do in-cylinder identification. Borrow one from a plumber buddy—that’s what we do! We decided to see just how well this little motor would run, so we bolted in a small Comp 219/223 hydraulic roller cam, retained the stock lifters, but added better springs. Then we bolted on an Edelbrock Performer RPM dual-plane, a Holley 750 HP carburetor, and the MSD ignition box to run the spark. The only other change was to a Champ LS engine swap oil pan to clear the crossmember.

You might recall that, with this engine in our Orange Peel Chevelle, it ran an 8.48 at 85 mph in the eighth-mile. Later, we ran the car at Bakersfield and its best was a 13.45 at 106 mph. The biggest disappointment was that with such a small engine, the 60-foot times were slow (2.02 being its best). But the trap speed of 106 mph was fun. We knew we could improve that e.t. with a better gear, but even with an overdrive trans, we didn’t want to put more gear in it than the current 3.55:1. Lastly, all these runs used a pair of Holley exhaust manifolds. A set of long-tube headers would have really helped the low-speed torque.

A series of “what-if” scenarios persuaded us to yank the 4.8L and stick it on the dyno. Remember, this is a 140,000-mile 4.8L truck motor with stock 9.5:1 pistons and heads. All we did was improve upon the camshaft and the induction. The only change we made on the dyno was to add a set of American Racing 1-3/4-inch headers. We wanted to test with the Holley exhaust manifolds, but our exhaust lead-down pipes wouldn’t clear the dyno stand.

Our first pull on the mighty 4.8L produced a surprising 383 hp out of this littlest warrior. Next, we’ve heard lots of rumors about how much power a stock LS water pump demands at rpm, so we thought we’d find out. Bolting on a Meziere electric water pump, the results were somewhat surprising.

At 6,000 rpm, the electric water pump added an amazing 16 hp at 6,000 rpm and bumped the peak horsepower an additional 10 to 393 hp. If you study the graph, you can see that Meziere’s pump improves the power throughout the entire run. Yes, part of this test did eliminate the alternator as well. If we assume an output of 50 amps, the conversion is 0.8 hp. This Meziere pump only pulls 7 amps, so the added electrical load of not quite 2 hp would be inconsequential.

For our final test, we wanted to evaluate a set of mildly ported production heads from our pal, Richard Reyman, owner of West Coast Racing Cylinder Heads (WCRCH) in Van Nuys, California. If you send him your stock 4.8/5.3L head castings, he performs a simple CNC pocket-porting job along with installing larger 1.95/1.57-inch stainless steel valves all for just $1,062.

After porting, WCRCH outfitted our heads with a set of (extra cost) Brian Tooley Racing (BTR) dual valvesprings and matching retainers and we bolted the heads down with ARP head bolts and new. The only other change was to mill a few thousandths off the deck surface to reduce the chamber volume to 53cc. This was worth almost exactly 1 point in compression, bumping our 4.8L to 10.5:1 compression.

From the first pull on the dyno by our pal, Richard Holdener, we witnessed an instantaneous push in torque and horsepower. This wasn’t just a gain at peak rpm. The head swap produced a 2-1/2 percent gain even at the bottom—likely due more to the compression ratio than airflow. At the top, the gains were far greater, producing an even 40 hp on this tiny dancer to create 432 hp at 7,000 rpm. Granted, that’s a lot of rpm, but the engine repeated this several times with nary a complaint. To put this in perspective, 432 hp from 293 inches is 1.47 hp/ci. That’s an outstanding number in anybody’s book.

Car Craft will soon drop the engine back into the Orange Peel Chevelle. Since the power numbers were mainly realized at higher engine speeds, they may mean only minimal gains in e.t. We expect to see bigger increases in trap speed mostly because Orange Peel is heavy with a 3.55:1 gear and a tight converter. Our expectations are for the car to run low 13s at 108 mph. With a 4.10:1 gear, it would easily push into the high 12s. Not bad for a $200 junkyard refugee!

Cam Specs

Ports O’Call

These are the WCRCH published flow curves for both the stock and ported versions. Stock valve sizes for the 4.8/5.3L heads are 1.89/1.55. The WCRCH heads use 1.95/1.57-inch stainless steel valves. All tests were performed on a 3.78-inch test bore using 28 inches of water test depression. The exhaust-to-intake percentage is a way to evaluate the relative performance of the ports. Anything above 70 percent is considered very good.

Power Curve
Test 1 was the 4.8L motor with the Edelbrock Performer RPM intake, Holley 750-cfm HP carb, American Racing headers, MSD ignition box, and the Comp hydraulic roller camshaft.

Test 2 exchanged the stock truck water pump for a Meziere electric pump.

Test 3 added a set of WCRCH stock castings that were lightly ported with larger valves and the same 26918 valvesprings. The numbers in the far right columns evaluate only the gains with the cylinder heads—the difference between tests 2 and 3.

As you can see from the graph, the combination of the heads and the electric water pump produced some serious gains with a peak horsepower of 432. What is even more amazing is that in all three tests, peak torque occurs at 4,000 rpm and peak power at or near 7,000—that’s a powerband of 3,000 rpm, roughly twice that of most engines.

Parts List

The post How to Make 430 HP With a $200 4.8L Engine appeared first on Hot Rod Magazine.

There’s an age-old problem in the design and modification of parts directed toward equal amounts of air-and-fuel charges among the combustion spaces of a multi-cylinder engine. It’s a given. As a practical matter, no two areas are more sensitive to this issue than intake manifolds and cylinder heads. As various techniques and measuring devices have evolved, the tools to determine cylinder-to-cylinder air -fuel mixtures have improved our ability to make these determinations.

Years ago, a relatively inexpensive approach was to measure exhaust gas temperature. Although this post-combustion method of determining efficiency variations among an engine’s cylinders was useful, it did little to provide more incisive information about the causes of these variations. We’ve even seen engine dyno packages fitted with an ability to measure carbon monoxide (CO) levels, thereby, enabling some sense of air-fuel ratios that produced the data. Comparing brake specific fuel consumption (BSFC) data as a function of engine rpm is another useful barometer, but it is accumulated data that does not distinguish individual cylinder performance. We need to move further back into the processes that produced (or caused) the inequalities in the first place.

Our discussion will be aimed at engines using carburetors, so we should begin our investigation by focusing on the overall intake track: the intake manifold and cylinder heads. Both dry- and wet-flow flow benches are the most common means of analyzing a given combination of manifolds and heads. But before we dig into using these two pieces of measuring equipment, let’s direct our attention to related terminology and flow conditions.

First, we know the flow of air and fuel into an engine is not steady state, which is an important condition to keep in mind. In addition, this flow is interrupted flow. Plus, we are dealing with a compressible substance (air) and an uncompressible substance (fuel). (No, we’re not going to include Nitrous Oxide. That’s an entirely different subject). We’re also dealing with substances (air and fuel) of different masses, with differences in kinetic energy at any point in the induction process. For example, air can assume any given flow rate more quickly than fuel, and lose kinetic energy faster than fuel. This is one way the two might become separated during a given intake cycle. Let’s take a look at a typical inlet cycle, applying these differences and their possible consequences.

Initially, consider examine pressure and kinetic energy excursions in a single-cylinder engine. Upon the opening of the intake valve, pressure in the cylinder is higher than in the manifold. Consequently, there will be flow back into the manifold until the pressure in the cylinder is equal to cylinder pressure. During this equalization time, exhaust residue flows back into the manifold (reversion), providing a certain amount of air-to-fuel charge dilution in the manifold. It is a valid argument to say anything (valve seat configurations, valve seat angles, etc.) that reduces back-flow into the intake manifold can decrease the amount of combustion residue (obviously not combustible) back into the manifold. Just beyond this point of pressure equalization (piston descending on its inlet stroke), the air-fuel charge flows into the combustion space and continues until the inlet valve closes. Virtually any abrupt change in flow rate can lead to some degree of air-fuel separation, largely due to the mass differences between air and fuel.

Simplified for purposes of this discussion, take this process and transfer it to a multi-cylinder engine running with a single-plane intake manifold. Even though there are some design variations among specific single-plane manifolds, basically all runners emanate from a common volume (plenum). This expose all cylinders to the possibility of air-fuel charge contamination and pressure variations (pulses) beneath and including the carburetor (also a pressure differential device). In some circles, all this pressure changing activity has been termed cross talk, which is certainly applicable to the overall picture, and it further supports the non-steady-state flow environment in a running engine.

There are several potential ways to address these problems. As a rule of thumb, typically when a flow direction occurs (particularly at runner entries or in the combustion space) a resulting energy change can cause air-fuel charge separation. One way to determine the probability of this occurring is with an airflow bench, running a J-probe pitot tube along the walls of the inlet path. The end of this probe is pointed against the flow direction, and any manometric readings lower than atmospheric pressure will identify areas where air-fuel separation might occur. Specifically, these surfaces are locations where boundary layers (typically on the flow passage surface) separate from the walls of the passage, and disrupt the union between air and fuel. In fact, these areas often benefit from a roughening or dimpling of flow passage walls, which tends to produce so-called Von Karman eddies or trails that tend to create energy on or near the boundary layer with the intention of minimizing air-fuel separation.

Here’s a simple and effective way to identify how inlet air influences air-fuel charge patterns. Connect any given intake manifold runner to the test cylinder head (flow-bench operating) and at a valve lift (on average) of 0.450-inch, shoot a few brief shots of machinists blue dye into the runner entry—just outside the entry—and turn off the bench. Remove and examine the intake runner, cylinder head, and combustion space in the head, to see where the fuel goes during engine operation. Well, it won’t be exact because you cannot duplicate all of the pressure excursions. However, this test will give you an idea, and it’s certainly better than relying solely on airflow numbers.

Of course, there are points along flow paths that produce some amount of separation, such as the short-side radius of the path as it turns beneath the intake valve and enters the combustion space. In this case, you can reduce the overall degree of separation over the entire inlet path to minimize the negative influence on air-fuel separation at this short-turn location.

Let’s get back to the flow equalization issue, cylinder to cylinder. Ideally, evaluate each intake manifold runner on an airflow bench, measuring the flow of each runner attached to the cylinder head port it will be servicing during engine operation. Simply flowing intake manifolds that are not simultaneously connected to the appropriate cylinder head port won’t give a proper flow analysis that shows how intake ports influence the manifold’s runners.

It’s no secret, any measuring techniques, short of running an engine, are simply that—measuring techniques. Understandably, different people have different ways to perform airflow analyses. Smokey Yunick once showed me a bench he had designed that enabled him to flow an entire engine and included provisions for evaluating airflow from the point of air entry all the way to air exit. You read that correctly. He could (and did) flow an entire engine, all at one time.

The time you spend evaluating the flow conditions and compatibility of intake manifolds and cylinder heads, if properly done, will pay benefits when you place these parts in their natural environment. Air is a fluid just like fuel. However, each has unique kinetic energy differences that you must address when attempting to create and maintain the proper union along the way to combustion.

The post Distribution Equality appeared first on Hot Rod Magazine.

With Forgeline wheels seemingly rolling on just about every pro-touring machine on the street or track, it was inevitable the Dayton, Ohio-based manufacturer would tackle the 21st century street machine genre with an entry of its own. From what we’ve seen of their car so far – a 1970 Camaro – it promises to set a new performance benchmark.

“We’ve been dreaming about building our own world-class pro-touring Camaro for years,” says Dave Schardt, the president of Forgeline Motorsports. “We’re a long-time supporter of this segment and have been the wheel of choice for many pro-touring builders. Now, it’s our turn to participate.”

Smitty’s Custom Automotive, in Tiffin, Ohio, got the nod to build the car and for good reason. Owner Chris Smith is one of the country’s premiere pro-touring builders and you’ve already seen his work if you’ve seen that dark red ’67 Chevy C-10 or screaming yellow C3 RideTech “48-Hour Corvette” at OPTIMA Challenge events.

“We’ve seen his work through events such as Goodguys and OPTIMA and knew he was the one for this project,” says Schardt. “We wanted to do a Gen 2 Camaro, as well, for a number of reasons, including the fact you can really shove some wide tires under it, compared to first-generation F-bodies.”

The car is also a showcase for the latest in crate engine supremacy: Chevrolet Performance’s Corvette Z06-derived LT4. It’s one of the earliest projects we know of to employ the new supercharged, 650-horsepower engine package (besides Chevrolet’s own SEMA show car). Naturally, some fabrication has been required, particularly when it came to resting the engine in a Detroit Speed front subframe and constructing the headers.

“I wanted the LT4 because I owned a new Z06 and felt the engine was the best part of the car,” says Schardt. “It has definitely brought some challenges, but that’s OK. Good things come to those who wait – and I’m really looking forward to putting this Camaro through its paces when it’s finished.”

Frankly, we’re angling for a little seat time in this high-tech street machine, too. The car was supposed to be done by the time we shot the accompanying build pics, but clearly the “to do” list didn’t quite jibe with the calendar. Nevertheless, the progress so far is encouraging and tantalizing. And with Chris Smith proving he’s as adept driving as he is building these cars, this Camaro is poised to shake up the ranks of the pro-touring hierarchy.

1. The heart of the project is Chevrolet Performance’s new LT4 crate engine, which is used straight out of the Corvette Z06. Its “wow” elements include Rotocast A356T6 aluminum heads that are stronger and handle heat better than the conventional heads in the naturally aspirated LT1 engine. The Eaton TVS-based blower also spins faster than the previous LS9 supercharger. It all adds up to 650 hp and 650 lb.-ft. of torque. It’s offered in wet-sump and dry-sump versions and Chevrolet Performance offers an engine controller for manual transmission applications, which is good, because that’s what this Camaro has. Scoggin-Dickey is selling them for around $14,000, which ain’t bad at all for 650 force-fed horses.

2. One of the head-scratchers the crew at Smitty’s Custom Automotive was grappling with during our visit was the power steering. The Corvette Z06 uses and electric power steering system, meaning there’s no conventional engine-driven hydraulic pump. It will have to be added to the engine’s drive system, but where the pump and requisite pulley would go was the dilemma.

3. Ultimate Headers tacked up a set of custom long-tube headers for the car. The unique feature of the headers is Ultimate’s flange, which is designed to seal better and reduce weight. They’re easily identifiable by the ribbed flange reinforcements around the tubes.

4. The crate engine doesn’t come with an air conditioning compressor, but that wasn’t a concern, because a complete Vintage Air A/C and climate control system will be fitted. The firewall was carved out to accommodate it.

5. A Detroit Speed hydroformed front subframe houses the LT4. Its strength and stiffness enable much more precise suspension tuning, because there’s less chassis flex. It also allows tires up to 10 inches wide to be used without modifications to the inner fenders. A little sheet metal work will be required here, because the 315-series front tires are 12.4 inches wide.

6. The Detroit Speed front suspension includes tubular upper and lower control arms, as well as a splined stabilizer bar and a rack-and-pinion steering system. The Detroit Speed-supplied coil-overs were swapped for Ridetech triple-adjustable shocks and springs. It’s a race car suspension for the street.

7. A TREMEC T-56 Magnum six-speed manual transmission backs the LT4, requiring a new sheet metal tunnel to tuck it up in the Camaro’s unitized body structure. The Magnum, of course, contains the stronger guts of the TR6060 transmission, but within the “envelope” of the T-56 gearbox. Note how the new trans tunnel cover is ribbed to match the original contours of the floor. Nice touch.

8. The rear axle is built to channel all of the LT4’s 650 lb.-ft. torque. It’s Moser-prepared, 3.89-geard 9-inch center section featuring an Eaton Detroit Truetrac diff. It’s all stuffed in a Detroit Speed axle housing that’s connected to the company’s QUADRALink a four-link rear suspension.

9. Detroit Speed deep tubs are de rigueur equipment on pro-touring F-bodies these days and this car’s got them. They allow up to 335-series rubber, but for the time being, the Camaro wears 315-series in the rear, just like the front.

10. More from the Detroit Speed catalog came in the form of subframe connectors – and while they’re unobtrusive beneath the car, they poke through the floor, requiring more sheet metal surgery than, say, welding a set of connectors to a fourth-gen F-body.

11. More work to come for the Camaro will include a RideTech TigerCage roll cage and a set of Baer Brakes 14-inch Extreme 6S disc brakes.

12. Of course, the car will roll on Forgeline wheels – 18-inch GA3C wheels, to be exact. Forgeline president found the Camaro only a couple of minutes from his home and purchased it from a customer.

The post Check out the new LT4 Swap in this 1970 Chevy Camaro! appeared first on Hot Rod Magazine.

Ever since Mopar began recasting the cast-iron 426 Hemi Gen II blocks in the 1990s, it stirred up lots of excitement. Then in 1998, the 426 Hemi crate engines were introduced with 426, 472, 528 and 572 cubic-inch offerings. Even though most of us know the 1990s through 2007-vintage Hemi blocks are substantially stronger than the ’60s and early ’70s castings, it’s the latest revised edition (2008 to current) that is the strongest. These later, beefier blocks can support up to a 4.600-inch bore and a 4.750-inch stroke (as long as an external oil pickup is used), giving a whopping 632 cubic inches! When the Mopar foundry recently reopened (it was closed for a few years making it difficult to obtain an iron Hemi block), we felt the time was right to order a new Hemi block should they once again became difficult to obtain.

For many years, this author has dreamed of owning a Barton-built Hemi to be under the hood of his Mopar muscle-machine. Ray Barton’s reputation for building the best race or street Hemi engine is undisputable. Barton’s innovative ideas have helped keep the Hemi on top, setting records for over 40 years. Fortuitously, the latest version Hemi block has lots of input from Barton. Finally, after a long hiatus in which Hemi blocks were made in a non-Mopar facility that made Chevy and Ford products, Mopar is now pouring the latest revised casting of the Hemi block at their own foundry. Great news for guys who want their machines to remain all Chrysler! With the new beefy block, the sky is practically the limit, but we decided to go with a pump-gas, naturally aspirated 528 Street Series Hemi crate engine from Ray Barton Racing Engines (RBRE). With a Barton-built 528 Street Hemi (700-plus hp) under your stock hood (flat, Air Grabber, Ramchargers, Shaker) you can have an old-school Hellcat killer!

In case you missed the last story with our new, reworked Edlebrock heads, Barton and his crew helped us rework the latest edition of the Street Hemi cylinder head, Edelbrock’s Victor Jr. These latest cylinder head castings also received input in design and development updates from the King of Hemis: Ray Barton. To begin our build-up, we ordered our 4.500-inch bore Mopar Hemi block (part No. P6163862, $3,700) through RBRE. At the time of this writing, there’s an 8-to-12-month waiting time for RBRE to custom-build a Hemi to a customer’s liking. People from all over the world want a Barton-built Hemi. Take a peek behind the curtain and follow along and see the special machine work that goes into a Barton-blueprinted Hemi block.

The post Behind The Curtain: Ray Barton Hemi Machine Shop Secrets! appeared first on Hot Rod Magazine.

The steady flow of high quality, affordable goodies for the big-block wedge keeps delivering one fantastic advance after another. It’s great news for Mopar folks old enough to remember the dark days when aftermarket heads were non-existent and the hottest wedges on the street wore radically ported iron castings based on Max Wedge or 1967 915 castings. Remember the absurd prices we paid for those one-year-only small-chamber, big-port lumps? Man, what a nightmare. With intake runner volumes far below 200cc, they were hard pressed to support one hp per cubic inch without radical surgery.

But happily today we can leave the iron to the resto crowd and take our pick from a wide selection of stock-replacement type aluminum heads from the aftermarket. When we say stock replacement, don’t assume we’re talking low-po Chrysler Imperial stuff. Instead, we’re simply saying they accept all standard-deck, intake and exhaust bolt patterns, and that conventional shaft-mounted rocker arms are compatible.

As for Trick Flow Specialties, they’ve been a major player in the aftermarket cylinder head game for over two decades, scoring huge hits in the Ford and GM realm with builders who grew to expect great things from their offerings. And now it’s our turn in the pentastar camp.

While there are a number of aftermarket big-block wedge heads to choose from with intake port runner volumes in the 210 to 270cc range, Trick Flow zeroed in on the mid-ground street performance sector and gave its new castings 240cc runners, thus the Power Port 240 brand name. For contrast, the intake port volumes in a typical cast-iron 440 casting measure well below 200cc. Needless to say, by enlarging the “hallways” through which the intake charge moves, each piston has access to a greater quantity of fuel and air—and potential power.

In this story, let’s observe as engine master Steve Dulcich puts the new Trick Flow Power Port 240 heads to the test. An extra bonus here is the inclusion of Trick Flow’s just-released Track Heat single-plane TFS-61600113 intake manifold. Trick Flow claims the new Power Port 240 heads can support 600 horsepower straight from the box, so how close would we be able to get?

The TFS power claim of 620 hp was made using a 10.5:1 440 with a .030-inch overbore, and a 241/246-at-.050 mechanical-tappet camshaft. Their claim was impressive considering the street-oriented nature of the cam and compression, so we opted for a similar route. Dulcich prepared a nearly identical .030-over 440 with 10.5:1 compression and a 242/248 solid roller cam with .587-inch lift using 1.6:1 rockers and the stock crank and rods. A Holley Ultra HP 1,000 cfm carb performed mixing duties and an MSD Pro Billet distributor lit off the mixture. Exhaust was handled by a set of full-length 1 7/8-inch TTi headers.

After a brief tuning loop to verify the optimal air/fuel ratio, a power pull was made, then backed up for verification. Power peaked a 561 hp (5,800 rpm) with torque peaking at 542 lb-ft (4,700 rpm). That’s a bit shy of TFS’s claim, but if nothing else, it does bear out the stingy nature of Westech’s Superflow dynamometer. Your results should easily match or improve upon ours, and this test should be considered the bare minimum you will get in a similar combo. Altogether, this is a budget-friendly combo that should easily propel the typical 3,400 – 3,600-lb Mopar into the high 11-second range using sticky rear tires.

On The Bench
TFS 240cc PowerPort

The post 440 Chrysler Dyno Test: Trick Flow Heads & Intake appeared first on Hot Rod Magazine.

THE COMBO
Eleven years ago, then 13-year-old Rod Arias inherited a 1989 Mustang LS V8 coupe from his newlywed brother, who could no longer afford to keep the car up. “When I first obtained the car,” Arias says, “all it needed was a clutch. Over the years, I’ve upgraded the rearend, the trans, and the brakes.” Currently, the original 5.0L engine (now with more than 100,000 miles on the clock) is exhausted through MAC headers and Flowmaster mufflers. Behind the motor is a Ford Performance Parts (FPP) World Class T5 trans and a 3.73:1-geared 8.8-inch Ford rearend with a Traction-Lok diff that’s supported by Roush rear lower control arms. The rearend, out of a 1995 Mustang GT, had five-lug wheels and rear disc brakes, so Arias decided to go to larger discs and five-lug wheels up front, too. “Installing 1994–1995 Mustang front spindles allowed me to bolt on much bigger 2000 Mustang GT front brake rotors and calipers. My long-term goal is autocrossing and drags, and I keep adding stuff as good used parts become available in the wrecking yard where I work. But this is still a street-driven California car, so it’s important to me it remain emissions-legal.”

“The 1993 Explorer intake swap is a great econo mod for 5.0L SFI Mustangs, but there are a few things that can trip you up.” — Mark Sanchez/AEW

THE PROBLEM
Arias’ troubles began when he grabbed the upper and lower intake manifold, injectors, and injector harness off a 1997 Ford Explorer when it passed through the yard. An Explorer intake is virtually identical to the 1993 Mustang 5.0L Cobra production intake and FPP’s GT-40 intake retrofit kit, but (since the Explorer intake is commonly available used) it goes for around $200, versus the $600 cost of the now-discontinued FPP package when it was still available new (used Cobra intakes are said to cost more than a grand). Obviously, this makes the Explorer conversion a popular retrofit for savvy Ford 5.0L SFI modders.
After bolting everything on, Arias says, “I started getting a little misfire and surging. The engine was running about 1-percent rich and the check-engine light kept coming on. I asked questions everywhere—mechanics, friends, online forums—but no one could figure it out.” Fortunately, Arias is a stone’s throw away from our favorite Southern California Ford rescue specialist, Mark Sanchez’s Advanced Engineering West (AEW).

THE DIAGNOSIS
Sanchez quickly confirmed Arias’ complaints. The motor was running slightly rich, there was an occasional miss, and the engine control unit (ECU) was setting the exhaust gas recirculation (EGR) valve and air charge temperature (ACT) sensor error codes. “Problems with the EGR can often cause a misfire,” Sanchez explains. “With no ACT provisions, the ECU can’t compensate for the air temperature entering the motor, so it won’t adjust the timing accurately.”
Looking further, Sanchez observed not only was the EGR valve electrical connector unplugged, there was also no coolant hose running from the lower intake to the EGR’s coolant passage. “Circulating coolant through the EGR housing reduces the exhaust gas temperatures to prevent tar buildup and keep the EGR clean,” Sanchez says. As for the ACT sensor, it was connected, but the sensor itself was just dangling in the wind.

The missing EGR coolant hose and the dangling ACT sensor provided a critical clue for Ford specialist Sanchez: On standard 5.0L Mustangs and the 1993 Cobra, the coolant hose nipple for the EGR and the ACT sensor screw into lower intake manifold bosses—but not so on the Explorer (or 1994–1995 Cobras), where, though present on the casting, these bosses are unfinished.

“It’s commonly overlooked on what otherwise is a great econo swap,” Sanchez points out. “I pulled the top half [of the intake] and confirmed the missing tapped bosses in the lower half. With the top half out of the way, I pulled the injectors in the lower half and examined them for any problems.” It turns out that half of them had damaged pintle shields; the 42-lb/hr nonstock units were also way too large anyway for Arias’ existing combo. Deteriorating seals in the stock throttle-body still in use on the car were also causing a slight vacuum leak.

THE INITIAL FIXES
Sanchez removed the lower intake so he could drill and tap the blank bosses. “It’s pretty easy—you just need the right drill bit and pipe tap to make everything good,” Sanchez says. He then screwed in the EGR coolant nipple and ACT sensor, reinstalled the intake, and added a set of new, correctly sized injectors. For reliability and consistency, Sanchez always replaces injectors as a matched set—in this case, “24-lb/hr FPP units that best match the intake and Arias’ other mods. I prefer genuine Ford OE, Motorcraft, or FPP injectors for their quality and consistency.”

A larger 70mm Accufab unit replaced the leaky stock throttle-body. “Accufab builds the extreme high-quality throttle-bodies for Ford for use on the GT500 and Cobra-Jet limited-production cars. They’re the only billet-aluminum throttle-body that meets Ford’s high-quality OE standards.”

LATE-STYLE FUEL INJECTORS NEED ADAPTERS
As received, the Mustang was running way too big 42-lb/hr fuel injectors, at least half of which were also damaged. Yet Sanchez says typical stock Mustang and Explorer 19-lb/hr injectors are way too small to support the larger Cobra-style intake in a performance application. In fact, the rare Cobra Mustangs used 24-lb/hr units. Sanchez still had a set of NOS, original-style (but now discontinued), EV1 Jetronic-type, 24-lb/hr injectors (old FPP PN M-9593-A302) that are a direct bolt in. FPP’s current replacement for them is a late-style, slimmer-bodied, EV6 USCAR-type injector, which requires an electrical adapter to connect to old EV1 harnesses. The Parts List on page 98 lists the newer parts and the necessary adapter package.

If you’re going the total budget route and shopping the wrecking yards, besides the 1993–1999 Mustang Cobra (which you’ll probably never see in a wrecking yard), Sanchez says the following more available apps also used 24-lb/hr direct bolt-in EV1 injectors:

• 1989–1995 Ford F-350 truck with 460 big-block
• 1994–1996 Lincoln Continental front-wheel-drive with 4.6L DOHC 32-valve modular motor.

Always thoroughly test and clean used injectors!

But here’s where the domino-effect kicks in. The larger throttle-body works better with a larger mass airflow (MAF) meter that’s properly calibrated to “fool” the ECU so it won’t set any codes. “We changed the MAF to a Pro-M unit. Pro-M is the only meter, in my opinion, that’s calibrated properly for the injector size and throttle-body you are using. Others may set a check-engine over-voltage code. Fortunately, as a 1989 California-emissions stick-shift car, this Mustang had the A9L ECU that has a very wide tolerance for modifications.”

Owner Arias threw in the smoothly-curved chrome induction pipes to streamline the induction tract. Of unknown origin, Arias says they’re pirated from a car that ran through his wrecking yard sometime in the past. “You never know when some of this oddball stuff will come in handy. I knew I’d find a use for them someday!”

Continues Sanchez, “Once I cleared the codes, modified the intake to accept the missing sensors, upgraded the MAF and throttle-body, and replaced the injectors, the car ran a lot better.” But later, Arias complained about one persistent remaining driveability issue.

THE FINAL FIX
“After driving the repaired car for awhile,” Sanchez says, “the owner reported there was still a surge under certain cruise conditions. However, I could not duplicate it. It took the owner driving (with me along as shotgun) to show me where the surge was occurring. My natural driving style was just different than his.” It turns out the problem only occurred intermittently in Third gear between 3,000 and 4,000 rpm at about 50-percent throttle.

At this point, the engine wasn’t throwing codes. The air/fuel ratio was correct. The no-load timing was correct. Sanchez suspected it could be an ignition issue, explaining that Fords sometimes have problems with the coil or the distributor. Sanchez first checked for a possible defective coil or spark-plug wire shorts and found no issues. He then checked the distributor for a defective module, another common problem. Although the module checked out OK, further distributor inspection revealed a magnetic pickup that improperly moved when the shutter-wheel/rotor rotated. For proper rotor phasing, the pickup is supposed to stay locked in place by what Ford calls an “octane rod.” In this case, the budget remanufactured distributor’s plastic octane rod was worn. Sanchez installed a quality Cardone remanufactured unit that, he says, “Definitely comes with a wear-resistant steel rod.”

THE RESULTS
“Everything now is running fine,” Arias says. The Explorer intake is a good shade-tree performance boost on a 5.0L V8-equipped Mustang if you’re willing to perform the necessary mods on the intake’s lower half. While not strictly necessary, a performance throttle-body and properly calibrated MAF meter will help the Cobra/Explorer-style intake achieve its full potential.

LESSONS LEARNED
Patience and a logical diagnostics approach will solve most problems, but it also helps to have experience in the brand and model’s individual idiosyncracies as Sanchez does.

NEED JUNK FIXED?
If your car has a gremlin that just won’t quit, you could be chosen for HOT ROD to the Rescue. Email us at PITSTOP@HotRod.com and put “Rescue” in the subject line. Include a description of your problem, your location, and a daytime phone number.

The post HOT ROD to the Rescue: Sorting Out Distributor and Explorer retrofit intake manifold problems on a 5.0L Fox-bodied Mustang appeared first on Hot Rod Magazine.

Horsepower: 2,500. Cubic inches: 430. Boost pressure: 45 psi. Cylinder pressure: Absolutely ridiculous. Running 6.80s at nearly 210 mph, today’s 275 drag radial door-slammers incinerate the quarter-mile thanks to obscene levels of airflow and grip. Producing close to 6 hp per cubic inch requires immense cylinder pressure that can split blocks, blow head gaskets, and melt pistons in a jiffy, but fortunately the aftermarket has methodically eliminated each of these weak links in recent years. While enhanced short-block durability is obviously a good thing, it places an even greater burden on the cylinder heads to keep all that pressure sealed inside the block. To meet the demands of today’s boost-hungry race engines, casting technology has evolved tremendously to spawn a new crop of incredibly durable cylinder heads.

While Edelbrock is best known for its extensive line of cylinder heads and intake manifolds, over the last 25 years the company has quietly established one of the most sophisticated foundry facilities in the country. Initially, the foundry’s primary focus was elevating the quality of the company’s street castings, but as racers continued pushing the limits of durability, Edelbrock developed many key technological advancements in an effort to create the strongest race castings in the business. In fact, when engineers realized that they had reached the limits of their first foundry, Edelbrock built a second foundry in 2007 better suited to the low-volume manufacturing requirements of its race cylinder heads.

The combination of old-school know-how and modern technology allows Edelbrock to dynamically adapt its casting process as circumstances dictate. “We’re always experimenting with new heat treat processes and testing new alloys and additives,” Dr. Rick Roberts of Edelbrock explains. “In the last several years, we’ve built a new permanent mold foundry and have introduced Hot Isostatic Pressing into our race cylinder head castings. All of these technologies are an evolution of established casting techniques that ultimately create a superior end product.”

Although building a foundry from the ground up wasn’t easy, the long-term benefits for hot rodders have proven to be well worth the investment. “Running a foundry in Southern California isn’t the cheapest way of doing business, but 25 years ago we felt that the only way to maintain the quality control we were looking for was to control the entire casting process from start to finish,” Roberts continues. “We’re fortunate that Vic Edelbrock Jr. had the foresight to build a foundry from the ground up in 1991.”

HIP

Every aluminum casting has tiny air bubbles trapped in it. The question is how much? “Hot isostatic pressing is a process originally developed by the aerospace industry to eliminate these microscopic air bubbles. The HIP process heats a raw casting inside a pressurized oven to about 900 degrees to make the aluminum pliable,” Roberts explains. “The oven is filled with argon to eliminate oxidation. As the pressure in the oven increases to 10,000-15,000 psi, it compresses the aluminum and squeezes out the air bubbles. The process actually shrinks the casting, so we have to make it a little bit bigger to compensate for the increase in density. HIP’ing dramatically enhances the overall strength of the casting. A HIP’d casting isn’t quite as strong as a billet cylinder head, but it comes pretty darn close.”

When Edelbrock began machining its first batch of HIP’d heads, the improvements in hardness were immediately apparent. “The material was so much harder that we immediately broke the drill bits,” says Roberts. ‘We can usually drill 17 head bolt holes on a cylinder head in five minutes, and the drills last for hundreds of sets of heads before they wear out. When we machined our very first HIP’d head, the drill broke by the time it got to the fifth head bolt. We had to change the drill speed and feed rate, as well as the drill itself, to account for how much stronger the casting was as a result of the HIP process.”

Nevertheless, the true test of any casting’s durability is how well it holds up in the heat of competition. The HIP process has proven its value in the most punishing race applications. Nine-time NMRA Street Outlaw Champion John Urist remarks, “The Edelbrock SC1 heads have the strength of a billet head, but they’re also easy to set up and machine. It’s the best of both worlds. The HIP process makes the SC1 castings so hard and dense that it lets you push the limits of the head much harder. You simply don’t have that luxury with other castings. Billet heads are great, but they can cost twice as much. A billet head also requires machining out the water jackets, but with a HIP’d casting like the SC1s, they’re already in there.”

With enhanced durability comes longer operating life, which equates to savings in both time and money. “Cylinder heads are an investment. Once you’ve spent money on extensive porting, you want to make sure the casting is going to hold up,” Urist says. “With other cylinder heads we’ve used in the past, we had to redo the valve job after five or six runs. When we disassemble the SC1 heads after a race weekend, the seats and guides haven’t moved around at all. In the past, we had to replace the heads every two seasons, but the Edelbrock SC1 heads are still going strong after eight seasons.”

Alloys

The U.S. Aluminum Association establishes specifications that outline the composition and mechanical properties of aluminum alloys. For example, an A356 alloy is mostly aluminum, but the percentage of silicon and magnesium it contains must fall within a specified range to qualify as A356. These metallurgical formulas also place limits on impurities like iron. Many of these elements represent just a small fraction of a percent in the overall composition of the alloy.

“Compared to A356 aluminum, which is a very popular alloy for cylinder heads, an A355 alloy contains much more copper,” says Roberts. “This may help with cooling because copper increases thermal conductivity, but overall the properties of the metal aren’t as durable as A356. In contrast, A357 aluminum alloys are often used in the aerospace industry. They offer greater purity than A356, but the benefits are questionable for automotive applications so the added costs are not justified. This explains why A356 alloys are so popular in automotive applications.”

Heat Treating

Without proper heat treating, raw castings are not strong enough to survive the stress endured in an internal combustion engine. Roberts explains, “The T6 tempering process—which is widely used in our industry—involves heating a casting up to 800-900 degrees, then holding it at that temperate for a specified period of time. Heating a casting up to a near-liquid state allows the particles inside the metal to dissolve in a uniform fashion. Next, the casting is quenched in cold water. After quenching, the soft and gummy structure of the metal suddenly forms a distinct grain structure. At that point you have a really hard aluminum, but now it’s brittle and prone to cracking. By heating the casting to 350-375 degrees for five or six hours, we can age the metal to put ductility back into the casting while maintaining hardness. The aging process takes a strawlike grain structures and breaks it down. Now you have a casting that’s very strong and easy to machine yet has enough ductility to prevent cracking. In contrast, the T5 tempering process ages the casting, but it does not quench the metal or heat it up as high as the T6 process.”

Formula Modification

Having complete control of the casting process makes it possible to experiment with different metal compositions and heat tempering techniques depending on the needs of a particular application. “Simply adding a tablespoon of copper or magnesium to a 400-pound batch of aluminum can have a noticeable effect on the properties of the metal,” says Roberts. “For extreme endurance applications, like offshore boat engines, we can go with a T7 heat treat to improve durability. In heavy-duty nitrous engines that experience incredible cylinder pressure, we can experiment with different additives to improve casting strength at high temperature. We’re always experimenting with different heat tempering techniques and additives to give us an edge. In fact, you can slightly underage or overage a casting and still fall under T6 standards.”

Ultimately, getting the formula just right comes down to experience. “Running a foundry is a lot like porting cylinder heads. The more gray hair you have, the better off you are,” Roberts jokes. “The specifics of what distinguishes a good casting from a bad casting doesn’t come from a textbook. It comes from experience. We’re very fortunate to have a couple of very talented foundry operators that each have over 50 years of experience. One of them actually helped pour the very first Donovan block.”

Controlled Solidification

After a casting is poured, the solidification of the molten aluminum must be controlled very closely to prevent air pockets from forming. “Aluminum shrinks as it solidifies,” says Roberts. “If you have a pocket of liquid aluminum that’s surrounded by metal that’s already gone solid, that pocket will tear itself to pieces when it solidifies because it wants to shrink but it can’t. To prevent this from happening, we pour the cylinder heads with the deck facing downward. Ideally you want the head to solidify from the deck to valve cover rail in a uniform fashion. A head that’s solid in one spot and liquid in another is a disaster in the making.”

When a head is poured, liquid aluminum travels from the pour spout into three or four passages routed underneath the cylinder head deck surface in the mold. From there, the metal passes through 1×1-inch gates before entering the mold. Once the metal fills the mold from the bottom upward, it enters several cylindrical risers positioned above the head.

“The risers act as reservoirs that feed liquid metal back into the mold as the head solidifies and contracts,” Roberts explains. “The diameter, height, temperature, and location of the risers all affect how a cylinder head solidifies, so these variables can be changed to eliminate hot spots as necessary. We can also move the gating around to address hot spots as well. Experience is key, and at Edelbrock, being able to get advice from people who have been working in foundries for 50 years is a huge luxury. It’s not hard, but when you’re trying to make changes to control how a cylinder head solidifies, the guys with experience know exactly which changes they need to make.”

Computer Simulation

Thanks to modern technology, it is now possible to virtually pour a casting on computer to identify trouble spots before they surface. “The Magma software we use is like a CFD (computation fluid dynamics) program that’s used to optimize the casting process. After we design a mold in CAD, we can compute how liquid aluminum will flow into it and watch it solidify on the computer screen,” says Roberts. “The software can predict the microstructure and properties of the finished casting as well as the location of hot spots. By simulating the pour process, we can identify potential problem areas and address them before we even bother making the first mold. Overall, computer simulations allow us to make better castings more quickly and inexpensively.”

Molds

As horsepower levels continue skyrocketing, the molds used in the casting processes have evolved to improve both casting quality and manufacturing efficiency. “Our green sand foundry uses a process very similar to what foundries in the 1950s used to cast iron blocks and cylinder heads,” says Roberts. “Green sand, which is actually black in color, is similar to the sand at the very edge of the water at the beach. You can almost see the imprint of your hand and feet in it, but not quite. Green sand can be packed down very tightly, but it also breaks down into loose sand easily. It’s used to create the envelope of a casting where the liquid aluminum will be poured into.”

Unlike a green sand mold, a permanent mold uses a steel envelope that works like a waffle iron. “As the liquid aluminum is poured, the chilling effect of the aluminum coming into contact with the steel mold creates a casting that’s structurally stronger,” says Roberts. “Since the mold is reusable, you don’t have to make a new mold out of sand after casting each cylinder head. The downside is that a permanent mold is three to four times more expensive than a green sand mold, so it only makes sense when casting in high volume. Most of our Performer RPM small-block heads are cast in our permanent mold foundry.”

Production Line Evolution

Edelbrock’s casting operations are split between the green sand, permanent mold, and dry sand production lines. The green sand line is a high-volume foundry that casts intake manifolds, water pumps, and many of Edelbrock’s street cylinder heads. The furnace holds 35,000 pounds of aluminum, and it runs 24/7 for 11 1/2 months of the year. “That’s good for high volume, but it doesn’t give us much leeway if we want to change the metallurgy of the aluminum for a small batch of cylinder heads,” Roberts remarks. “If we shut it off at night, the metal would harden and take a very long time to melt again. Over the years we have transitioned our highest-volume cylinder heads to the permanent mold process to improve casting quality and efficiency, since permanent molds are reusable.

“The challenges we encountered while casting our first SC1 race heads made us realize that we needed a third production line to handle more specialized castings. When we designed the green sand foundry, the big-block Chevy cylinder head was the biggest part that we made. We never envisioned casting a head with 3/4-inch-thick port walls. After pouring the first SC1 head, the mold started bubbling and hissing from all the turmoil going on inside of it. Metal spewed out of the pour spout, and we were afraid that it was going to explode. We found out pretty quickly that we reached the limit of the green sand process with the SC1 heads. With heads that require that much metal, the green sand casting process makes it impossible to feed the mold quickly enough. By replacing the outside of the mold with dry sand, we were able to make the mold as large as we wanted. That enabled us to change the way the liquid metal feeds into the mold, and solved the problem.

“After that experience, we decided to build a separate dry sand foundry so that we could cast much larger and heavier race heads. The dry sand molds cost twice as much as green sand molds, but we’re now able to cast heads that are 50-percent larger than the SC1 heads without any problems. Likewise, since the dry sand production line only melts 400 pounds of aluminum at a time, we can pour cylinder heads in small runs of 10-12 units. This allows us to experiment with different additives to strengthen the metal. Investing in the dry sand foundry was a very big step that we took 10 years ago that now makes it possible to build extremely durable race castings like our Ford SC1, GM LSR, spread-port big-block Chevy, and many of our Pro-Port raw cylinder heads.”

Green vs. Dry Sand

Shaping liquid aluminum to exacting tolerances with sand can be challenging, especially when the slightest deviation in the contours of a port can dramatically affect performance. Depending on the profile of the shape that needs to be made, Edelbrock uses green sand, dry sand, or a combination of both. Roberts says, “Green sand is a mixture of sand, clay, and various chemicals. Its clay and moisture content make it easier to shape but burns off after each casting run. While it can be tightly packed together, it doesn’t bind or get hard. That enables green sand to hold together well during the casting process, but you can still pull it apart by hand, replenish the clay content, then reuse the sand. Humidity can affect the moisture content of green sand, so the mixture must be monitored and adjusted as necessary.

“On the other hand, dry sand uses an adhesive as a bonding agent and its smaller grain size creates a smoother finish on the casting. It gets hard as a rock after sitting for 30 minutes, and you have to hit it with a hammer to break it. Green sand is versatile enough to shape all the features under the valve covers, like the oil drains, but it has its limitations. Dry sand works much better with casting shapes that have a lot delicate and intricate features. Even in our green sand foundry, the cores used to form the ports and water jackets of a cylinder head are made from dry sand.

“Fine, narrow pieces of green sand don’t mold or form very well, and are prone to breaking. However, making shapes like that aren’t a problem with dry sand. The dry sand is used to form the outer envelope of a cylinder head is reusable, but the sand used to form ports and water jackets is not reusable. That increases costs significantly, but sometimes that’s what it takes to cast a cylinder head strong enough to handle the most demanding race applications.”

Core Production

While a casting mold determines the outer shape of a cylinder head or intake manifold, cores must be inserted into these molds to form any internal passages such as the ports and water jackets. The old method of making cores involves mixing sand with glue, packing it into a mold by hand, then waiting half an hour for it to harden. It’s slow and tedious, but it works fine for low-volume production runs in Edelbrock’s dry sand production line. However, newer hollow-core and sulfur-dioxide core processes handle high-volume production more efficiently.

The traditional shell (hollow) core process uses a cast iron box that looks like the actual cylinder head. “After heating up the box and connecting a hose to it, sand is blown into the mold. The sand is impregnated with glue that’s activated by heat, so it solidifies when it comes in contact with the hot cast-iron mold,” says Roberts. “The sand in the center of each core doesn’t heat up as much, so it falls out after it’s removed from the mold. You’re left with a hollow-shell core that’s very accurate and well suited for high-volume production. The downside is that since the core box is made of cast iron, it’s very heavy and difficult to modify if we want to change the shape of the cores. The cores used to build most of our Performer RPM cylinder heads are made using the hollow-core process.”

About 20 years ago, Edelbrock began transitioning over to a sulfur-dioxide core process. This uses a different mixture of sand that has binders instead of glue. These binders are activated by sulfur dioxide, which means that hot cast-iron molds are no longer necessary. “Instead of iron, we can use a plastic mold, blow sand into it, then fill it with sulfur dioxide to harden the sand cores,” Roberts explains. “Not only does this enable us to work at room temperature, but it also makes it much easier to repair or modify the molds since they’re plastic, not iron. Even though the sand is abrasive, the plastic is very tough and wear resistant. Over the years we have gradually converted our production lines from the hollow-core to the sulfur-dioxide core process.”

Testing

Compared to foundries built in the 1940s and 1950s, Edelbrock’s casting facilities are relatively young. With this youth comes testing equipment that closely monitors all aspects of foundry operation. “Every morning we take a sample of A356 aluminum that’s the size of a hockey puck,” says Roberts. “After it cools we inspect it under an electron microscope to ensure that it’s structurally sound. We also have a pull-tester that stretches each metal sample until it breaks. That way we can measure the tensile strength and yield strength of our castings, and make sure they’re within our target range. We also have a room that’s always measuring the content of our green sand. Although 80-90 percent of it is reusable, a certain amount of clay content burns off, so we have to closely monitor the sand content and replenish it with clay as needed.”

Pattern Making

Just like the rest of the casting process, the art of pattern making has changed tremendously in the last 70 years. Back in the day, Vic Edelbrock Sr. sketched his intake manifold designs on paper and took them to his pattern maker, Harvey Hartman. Roberts says, “Vic loved the pecan pie that Harvey’s wife made, so he enjoyed sitting down at the kitchen table and going over his designs with Harvey. The patterns were hand-carved out of wood in that era, so the real specifics of what the pattern looked like was up to the pattern maker.”

These days the entire casting, including the pattern, is designed using 3D CAD software. “Pattern makers don’t have the same creative flexibility they used to and stick closely to the designs that the engineers give them. The tooling for a cylinder head costs $50,000, so you don’t want to make any mistakes,” Roberts remarks. “CAD software allows us to virtually design the entire cylinder head, flow test it, and machine it all on computer. We can make test prototypes using our 3D printer as well. All of these tools allow us to eliminate mistakes.”

Once the design is finalized on computer, the CAD file is sent to Edelbrock’s in-house pattern department, which designs the patterns and the mold to mimic the shape of the cylinder head. “Wood eventually wears out from sand abrasion, so patterns these days are made from plastic and cut on CNC machines,” says Roberts. “The design of the patterns and mold must account for sufficient draft (angle) to drain the sand cores after casting. Ultimately, all of these measures make it possible to make very precise patterns that contribute to a high-quality casting.”

Racer Testimonial

Phil Hines, two-time NMRA Street Outlaw Champion, says, “I love the Edelbrock SC1 cylinder heads. They are by far the best small-block Ford cylinder heads I have ever used. At this horsepower level, you find the weak spots in a casting very quickly. In the past, I’ve had heads that crack on the corner cylinders, but since switching to the SC1s, they have been bulletproof. Forced induction engines put a lot of heat into the valves. I compete in a ton of races each year, but I can go half a season with the SC1 heads before they need a valve job. That’s a lot. The HIP process makes these heads so durable that I have no reason to go with a billet head. The casting strength also lets you get very aggressive with the porting without sacrificing durability.”

The post How It Works: Edelbrock’s HIP Cylinder Head Casting Tech appeared first on Hot Rod Magazine.

We build an almost budget stock block for turbocharging

“No replacement for displacement” has long been elemental t-shirt slogan wisdom in car crafting. If it were true, we would expect the early leviathans of motorsports such as Giovani Agnelli’s 995 cubic-inch FIATs and Henry Ford’s 1155 cubic-inch 999 racer to dominate small-cube whippersnappers.

But back when the CC Underbird was a new car, “turbo” became a nuclear-hot marketing buzz word on the staggering strength of 91.5 cube Formula One engines. These tiny 1.5-liter Grand Prix mills of the 1980s flashed to more than 1300 horsepower for three to four minutes of qualifying time on hand-crafted, custom brews of aromatic hydrocarbons euphemistically described to the awed masses as “gasoline.”

Before long, nearly every fast and furious vicenarian “tuner” believed any ordinary VTEC Honda was 1,000 horsepower ready. These young tuners mostly dismissed the hulking Hemis, Bosses and Rats of the 1960s as quaint and useless as dial telephones and slide rules in the glorious new world of microchips. Out of the cacophony on America’s boulevards emerged a great divide: old school, mossback Luddites clinging to the glory days of their antiquated, carbureted big block V8s versus the fresh, technological zealots who placed their new-age automotive faith in DOHC, R.P.M., EFI and boost.

None of that was really new. The truth is displacement has often been replaced throughout the history of the automobile. Even the 1000 cubic-inch mastodons were quickly slain by the 1912 DOHC Peugeot on less than half the displacement. Forced induction became a motor sports equalizer by the early 1920s. 1,000 horsepower turbocharged Porsche 917/30s destroyed the Reynolds Aluminum Chevy Rats in early1970s Can-Am racing.

Yet the old saw “no replacement for displacement” hangs around like mullets and Daisy Dukes at a NASCAR show because, all other things being equal, it mostly works. The current stars of the streets, such as Larry Larson, Jeff Lutz, and Tom Bailey rule with outrageous, hyper-expensive mixes of boost and mountain-motor cubes. Moreover, the price of making big, streetable horsepower with high RPM, small-bore engines remains shockingly high. For example, one of the clean hands magazines recently claimed the ticket price of a professionally built 750-horsepower vintage racing NASCAR mill is over $60,000.00. And such a millionaire’s mill would hardly be streetable.

KILLING “MYTHSTAKES”

The displacement versus technology debate has fostered a few false beliefs. Among them is the idea that turbos are only good for small engines, and that turbocharging a big American V8 is as silly as putting Linda Vaughn in a Prius. Another canard is the claim that you need the massive budget of a Lutz, Larson, or Bailey and a best-of-everything parts list to successfully turbocharge anything bigger than a weed whacker. We are out to harpoon these mythstakes with the CC Underbird (or scatter a lot of cheap parts trying).

It seems in the age of the Dodge Hellcats, you need a power-to-weight ratio of at least 5-6 pounds per horsepower to be taken seriously. Any number of “dream wheel” horsepower calculators and simulator programs predict that five pounds per horsepower ought to be good for around 135 m.p.h. in the quarter mile. In a typical 4,000 pound street/strip/grand touring car, it takes at least 800 solid horsepower to run that fast. Any number of powerplant combinations will hit that bogie. We hope to obliterate it.

WHY A 460 FORD?

We chose Ford’s 460 for our initial attempt, based on many of the same reasons Ford offered that gargantuan lump in the smog-choked 1970s. An oversized, robust, relatively slow-turning V8 is still one of the cheapest ways to generate a massive torque curve. We also anticipate that a modestly turbocharged stock block 460 will be more reliable and tractable than a high reving, hyper-turbocharged micro motor or a cammed-up, all motor stroker of similar peak horsepower. We want the CC Underbird to be somewhat pump gas friendly, too. So the simplest, if not cheapest way to achieve that is with a long block as mild as Mister Rogers was on a summer Sunday morning.
Some racers, railbirds, and keyboard warriors will properly question all of this. Why not a lighter Windsor or a Modular or even a GM LS V8? We ruled out the stock block Windsors because of their unfortunate propensity to divide themselves at the 600+ horsepower level. John Kaase claims the production 460 block will hold up under the strain of at least 900 horsepower. Turbo expert Corky Bell points out that high RPM-based horsepower is much more stressful on an engine assembly than similar lower RPM turbo grunt. We eliminated the junkyard turbo favorite LS engine because we wanted the CC Underbird to be welcome at all-Ford events, and because we will enjoy all of the I-told-you-sos when our lump of hope gets schooled by those “budget” 5.3 LS/S400 turbo cars (or more likely fragments like Waterford crystal tumbling in a cement mixer). And we fought the strong urge to use a Ford Modular or Coyote because our wallets are as thin as Flat Stanley on a hunger strike.

On the turbo-phobic flipside, some ask why not just drop a dirt-cheap, plate nitrous kit on a junkyard big block? Nitrous may be initially cheap, but as every manifold explosion on Street Outlaws suggests, it can quickly get expensive. And bottle capacity always cramps the fun. Nitrous is also mostly useless on a road course and illegal in many venues.

Others say why not a brutally simple “all motor” Kaase Boss 9 or even a conventional TFS head 460 stroker? While we dream about such screaming, blueprinted, under-hood art, assembled by a legendary engine master, we always wake up troubled by niggles such as food, clothing, and shelter. Besides just buying the bespoke top-end parts of the incredible Kaase Boss conversion would cost as much as our whole engine and twin turbo system combined.

Any number automotive scribes have offered variations of the acronym PLANS to summarize the basics of making more power. PLANS stands for (cylinder) Pressure, (stroke) Length, (bore) Area, (cylinder) Number, and (R.P.M.) Speed. While our loud, fast and real Ford 460 may not be the absolute bottom-dollar way to go fast, it should yield a substantial increase in PLAN over the stock turbo 4 without the huge cost multiplier of higher R.P.M. speed. But before we get to the flashy turbo and fuel system bits, we are blowing the lid off of just how stingy we really are.

Parts List

The post Project CC Thunderbird: 460 Long Block “Plans” For Speed appeared first on Hot Rod Magazine.

Through the years as we continue to play with old trucks, it seems as though our standards rise as we go. Some may remember differently, but in my own high school Auto Shop class, back in the mid ’70s, engine swappin’ was not a refined art form, and when splittin’ differences was necessary, radiator flex hoses were an acceptable path of least resistance.

Now as I seem to recall, it was later in the smooth, red ’80s when molded radiator hoses began to appear more frequently on high-tech works of art. That may have been my own personal turning point. It was time to forget about flex hoses and step up. Thirty-some years later, however, I still don’t recognize needed shapes and sizes. I can’t just peer into an engine bay and come back with perfect-fitting hoses, but that’s OK. My ringer parts guy can.

For odd-application, molded radiator hoses, I’m quick to call upon my friend, Mike Ferguson, for assistance. Ferguson is the type of “real” parts guy that the elderly amongst us were likely spoiled by, and he’s not intimidated by one-off radiator hoses. For those in need of an example, how about molded hoses for a small-block Chevrolet engine—swapped into a low-tech ’47 Brand-X pickup?

The post Radiator Hoses appeared first on Hot Rod Magazine.

“Successful contenders learned to close their eyes and . . . listen”
“Lesser muscle simply wasn’t in the same league”
“Plenty of folks credit 12-second timeslips to L78s they’d forgotten were bolstered with headers, cam swaps, and other go-faster add-ons”

Chevelle spotting in the 1960s involved a lot of guesswork and speculation. Though the fender emblems read “3-9-6,” the actual, canted-valve Turbo Jet beast under the hood could have been one of three very distinct versions with anywhere between 325 and 375 “rated” horsepower. This made things risky for would-be stoplight challengers sizing up the SS396 in the next lane.

Though every 1966-1970 SS396 Chevelle featured a power dome hood, rode on an extra-beefy 12-bolt rear axle, and had dual exhaust, those visual tips were of no use in determining if, say, your 383 Magnum, 390 GT, or 389 Tri-power was up to the particular job at hand. Successful contenders learned to close their eyes and . . . listen. By their distinctive clatter the solid lifters fitted to the top-tier L78 396 would make themselves known

Lesser 325- and 350hp 396s didn’t “make the click” since GM fitted them with low-maintenance hydraulic lifters—and lower compression, milder cam timing, 10.25:1 compression, smaller round-port heads, 2.06/1.72 valves, and less efficient round port intake manifolds with Rochester carburetors (1967 and up; a small 585-cfm Holley 4160 was used in 1966). Here, a 383 Road Runner or Firebird 400 stood a good chance of victory.

As for the top dog L78, every one came with a hot solid-lifter cam, 11.5:1 compression, big square-port heads with upsized 2.19 intake valves (the 1.72-inch exhaust valves remained), and cast aluminum high-rise intake manifolds with a 4150-series Holley quad packing 780 cfm. A virtual twin to the first big-block engine offering in Corvette, where advertising forces nudged output up to 425 hp, the L78 would later share cylinder heads and camshaft with solid-lifter Corvette 427s and the mighty LS6 Chevelle engine of 1970. Stomping an L78 called for 440 Six Pack, Ram Air IV, or W-30 equipment. Lesser muscle simply wasn’t in the same league.

But looking back, how much power did a stock L78 really make? All too often, day-two aftermarket bolt-ons obscured their true potency, and plenty of folks credit 12-second timeslips to L78s they’d forgotten were bolstered with such go-faster add-ons as headers, nonstock intake manifolds, and cam swaps.

For this story we hooked up with R.A.D. Auto Machine in Ludlow, Massachusetts, where a customer’s 1969 L78 Chevelle engine was being refurbished and then dyno validated. Let’s zoom in and see what made the L78 go tick, tick, tick.

The Dyno Doesn’t Lie

Chart 1

Dyno Results, Stock Cast Iron Exhaust Manifolds

Chart 2

Dyno Results, Headers

The post Chevrolet Lied! Stone-Stock 1969 L78 396 Big-Block Makes 50 HP More Than Factory Rating appeared first on Hot Rod Network.

Internal combustion engines have been around for some time—the concept was first patented in the mid ’50s and it’s been undergoing refinement ever since. But regardless of the technology that has been incorporated in those gas burners we have grown to love are basically air compressors with fuel and ignition systems.

The operation of a modern automotive gasoline engine is simple enough, it begins when the piston descends in the cylinder on the intake stroke, a low-pressure area is created, and atmospheric pressure causes fuel and air to flow in through the intake port. The piston then rises on the compression stroke, squeezing the fuel and air into the combustion chamber. The fuel is ignited and the expanding gases push the piston down on the power stroke. Finally, the piston rises on the exhaust stroke and the cylinder empties to begin the process again. If there is any shortcoming in this process it’s the power that is produced is dependent on the engine’s volumetric efficiency (VE) or how well the cylinders fill on the intake stroke. With naturally aspirated engines atmospheric pressure provides the pressure to fill the cylinders, which is why they run better at sea level where the atmospheric pressure is higher than high altitude where the pressure is lower. In any case the cylinders in most engines are seldom filled as well as they could be with VE as low as 75 percent for typical “low performance” engines. High-performance engines may reach 85 to 95 percent VE and heavily modified engines may do better yet.

Superchargers

There is no question that the most direct means to enhance engine performance is to get more mixture into the cylinders—and supercharging is the most effective way to do that. Forcing fuel and air into the cylinders with a pump, or supercharger, increases volumetric efficiency dramatically, as much as 50 percent more than is possible with normally aspirated engines.

Superchargers have been around almost as long as the internal combustion engine. Gottlieb Daimler received a German patent for a supercharger in 1885. Today superchargers come in all shapes and sizes, but for the most part they can be divided into two categories: exhaust driven and crankshaft driven.

Turbochargers use the energy in the exhaust leaving the engine to drive a turbine. In turn the turbine drives a compressor wheel in a separate housing, which pressurizes the intake tract of the engine. While turbos are extremely effective, they do have some drawbacks. One is what is often described as turbo lag. In some cases it takes time for the turbo to “spool up,” or spin fast enough to create boost, so low speed throttle response is not as immediate as with crank-driven superchargers. Due to the exhaust plumbing installation can be complicated, and matching the size of the turbo to the displacement of the engine is critical for optimum performance across the rpm range

Certainly one of the most recognizable engine-driven superchargers is the Roots style, particularly the iconic GMC that topped all those great front-engine top fuelers. While Roots superchargers produce boost right from idle, they are rather large and can be complicated to install. A variation of the Roots supercharger is the axial-flow type that compresses the air as it moves between the screw-like rotors to create positive pressure without creating the heat the GMC type create and are more compact than the GMC and its derivatives.

Centrifugal Supercharging

Another version of a belt-driven supercharger, and the style we chose for the installation shown here, is the centrifugal type from TorqStorm. Similar in design to a turbocharger, these superchargers are belt driven by the crankshaft rather than being spun by exhaust gas. They are compact, are the easiest to install, and because they use centrifugal forces to compress the air these superchargers are more efficient in terms of power consumption and heat production.

According to the manufacturer, Accelerated Racing Products (a division of Accelerated Tooling) the TorqStorm scroll and impeller combo moves enough air to support upwards of 700 hp with intake temperatures of 185-200 degrees on a hot day. To accommodate various applications the scroll can be rotated on the supercharger body.

Engine Modifications

In most cases a stock engine in good condition will handle a centrifugal supercharger with boost in the 6- to 8-pound range. However, much above that, beefier connecting rods, forged pistons, and a stouter bottom end are wise additions. Although head modifications can be beneficial, for most street applications stock heads will suffice, as the blower will do the work.

As for camshafts, in most cases on the street the OEM profile will work fine. However, keep in mind all grinders offer profiles intended specifically for supercharged applications. However, be aware profiles will be different between a Roots- or screw-type supercharger and a centrifugal style. Always get the manufacturer’s advice when choosing a cam for a supercharged engine.

Fuel System

To realize its full potential a blown engine must have an adequate supply of fuel, in most cases that means increased carburetion capacity or larger fuel injectors to supply the engine’s demands. In our case the FAST fuel injection was equipped with Aeromotive fuel rails mounting 60-lb/hr injectors

Ignition System

Because of the increased cylinder pressures, blown engines require an ignition system capable of delivering a strong spark with increased cylinder pressures. We used Flame Thrower coils controlled by a FAST ECM.

Blow-Off Valve

The vacuum-controlled blow-off valve protects the system—it releases excessive boost, preventing damage to the system if the throttle suddenly closes on deceleration.

Intercoolers

When air is compressed it heats up and becomes less dense—that means there is less oxygen per cubic of air the engine takes in, which means less horsepower. To cool the engine’s incoming charge and increase density, intercoolers are often used. Ours came in kit form from Summit.

A Case In Point

Our Tech Center manager, Jason Scudellari, has been working on a 1956 Chevrolet pickup for some time. Riding on a Fatman Fabrications chassis, power is provided by a GM LS3 equipped with a COMP Cams camshaft, Eagle bottom end, RHS heads, and FAST electronic fuel injection. Even with that collection of parts Scudellari decided there was room for improvement, so he bolted on a TorqStorm supercharger.

As the TorqStorm comes with detailed instructions and is easy to install we’ve elected to concentrate on what Scudellari did after the supercharger was in place. Take a look at this compact and sanitary installation for some great examples of putting your truck under pressure.

The post 1956 Chevrolet Pickup – Blower Basics: Installing a Centrifugal Supercharger appeared first on Hot Rod Network.

In a typical four-stroke cycle engine, it is virtually impossible to avoid some form of contamination in otherwise combustible air/fuel charges. But before we dig into the effects of such contamination, let’s look at the conditions that can cause it in fresh mixtures.

First, pressure conditions in the inlet and exhaust paths and corresponding pressures in the combustion space, throughout all four cycles. To make this as simple as possible, our example engine will be a single-cylinder design.

The reversion process begins at the opening of the intake valve. At this point, the exhaust valve is open and has usually been allowing combustion residue to exit the engine. When the intake valve begins to open, pressure in the intake manifold in a normally aspirated engine is at or below atmospheric—generally, below—and residual exhaust gas begins to flow back into the intake manifold. This condition continues until the pressure in the intake manifold is briefly equal to cylinder pressure. Even though the intake cycle begins before the piston reaches BDC on the exhaust stroke (considerably before with racing engines), a certain amount of incombustible gas has already entered the intake track.

As a function of revolutions per minute and when the intake valve begins to open, efficiency of the exhaust system and related variables, the time and distance traveled into the intake manifold, and volume of contaminating gases varies. Generally, the higher the engine speed, the less time for this transfer to occur, but it happens nonetheless. I’ve seen engines running at relatively low revolutions per minute and wide open throttle display a cloud of vaporized fuel above a carburetor’s air horn. As engine revolutions per minute increases, this cloud is forced into the engine due to the reduction in time for the so-called standoff cloud to form. Intake manifolds that employ some type of plenum volume tend to minimize this condition, when compared to individual runner (IR) manifolds that typically do not use plenums or some method to dampen pulses.

As revolutions per minute increases, reversion contaminates the combustion process. I’ve seen reversion cases sufficiently serious it stains the bottom of the carburetor throttle plate with exhaust gas. The stronger the reversion pulse, the greater the amount of energy needed to equalize intake manifold and cylinder pressures to allow the intake cycle to begin.

At some moment in the reversion process, pressure in the intake path and cylinder equalize. With the exhaust valve closed, the true intake cycle begins and allows atmospheric pressure to force and fuel into the cylinder. Eventually, the intake valve closes, the mixture compresses and ignites, and the entire process repeats.

Take what occurs in a single-cylinder engine, and visualize connecting seven more single-cylinder intake manifold runners to a common volume (plenum). Depending on the engine’s firing order (let’s say its 1, 8, 4, 3, 6, 5, 7, 2) and the fact all runners usually share the same reversion cycles and periods (unless something has been changed in the camshaft’s design to address the problem), you can see there are noncomparable pressure conditions among the runners. For example, even though they are side-by-side in their union with the manifold’s plenum, runners 4 and 2 are separated by several crank degrees, as compared to cylinders 5 and 7 that do not enjoy that separation. As a result, among other related issues, air/fuel mixture distribution between the latter two cylinders is often a problem with this firing order when using a single-plane manifold. Note that cylinder 7 begins its reversion and contamination period during the intake stroke for cylinder 5.

It’s not just that the reversion/contamination situation is isolated to individual cylinders. This so-called cross talk among cylinders joined through the plenum chamber can have a negative impact on combustion efficiency and power. The problem is somewhat comparable to the short-runner/long-runner design in these types of intake manifolds. The conditions of other cylinders can affect the performance of any one cylinder. The bottom-line, there is two-directional flow in a typical inlet path and the material passing in either direction, toward or away, from the cylinders isn’t always combustible or contamination-free.

Even if we attempt to rid the combustion space of contaminants, more than likely, when the combustion process begins there will still be some incombustible material in this space. And it will have displaced any fresh air/fuel charges that are combustible. Not unlike the introduction of recirculated exhaust gas (EGT) for the reduction of NOx (emissions reduction), residual exhaust gas in the combustion space will reduce net heat produced, thereby, causing a decrease in power and on-track fuel economy.

Yes, extreme reversion can create a fuel standoff condition, particularly in a single-plane intake manifold. Actually, the same condition could potentially exist in fully divided two-plane designs, except for the dampening effect provided by this type design.

How can you identify signs of reversion and address the problem? Here are a few of the more common ones. Inspect the areas around the cylinder head and manifold surfaces. Traces of exhaust gas coloring in such locations indicate reversion. Check for such traces on the long side of the manifold’s runners, particularly in single-manifold designs. The underside of carburetor throttle plates is another indicator. In addition, a rapid increase in brake specific fuel consumption (BSFC) numbers above peak torque revolutions per minute and reduced combustion efficiency is likely being affected by reversion (contamination). Under such conditions above peak torque, you may see a reduction in EGTs below what you’d expect at higher rpm power levels. Exhaust gas residue tends to reduce combustion temperatures.

Interestingly, you can address a few things in the cylinder heads to reduce the reversion. One, improve low-lift flow in the exhaust port. A reduction in backpressure and a re-shaping of exhaust valve seats, pockets, and ports, can help. Also work on a reduction in flow direction back toward the combustion space. Valve seat and head modifications that help keep flow away from the combustion space and not travelling in a back-flow direction can address this issue. To evaluate such modifications, you can reverse-flow intake and exhaust ports (on an airflow bench) and determine how effective your modifications have been for the low-lift flow. By increasing low-lift exhaust port flow, you will be trending toward lower backpressure when the intake valve first begins to open. This will reduce the strength of reversion spikes at this point in the intake cycle and net potential for increases in volumetric efficiency (torque).

See the little sketch of a time-pressure trace that chronicles the positive and negative pressure history during one full intake cycle. It represents a measurement taken approximately at the junction between the cylinder head and intake manifold on a running engine. This is what you’d see in a single-cylinder engine. You’ll recall the complexities introduced with a multi-cylinder engine using a single-plane intake manifold. Regardless, the illustration here sheds light on the actual pressure excursions.

The amplitude and duration of the initial spike represent the reversion period. The area bounded by the horizontal axis and the pressure trace represents the filling or volumetric efficiency of the engine. Finally, the little spike at the end of the cycle amounts to the decay of the energy once the intake valve closes. Any successful attempt to reduce the amplitude or duration of the reversion spike usually nets a power increase (increased volumetric efficiency).

Any changes in air flow pressure differentials or pulses created across a carburetor can alter the amount of fuel delivered to an engine and upset the desired carburetor calibrations. It’s best to identify the presence of reversion and take steps to reduce its effects on your engine power.

The post The Effects of Reversion on Combustion Efficiency and Power appeared first on Hot Rod Network.

Welcome to the second installment of our stroker FE engine buildup for our altered project. If you were with us last time you’ll recall we’re working with Barry Rabotnick at Survival Motorsports, one of the nation’s authorities on FE engines. Our goal: We want to build an anvil. Nothing exotic, high-strung, or fragile. We don’t want an 800hp monster spinning at 7,500 rpm. We want to race, not constantly work on the engine.

The foundation is a swap-meet 390 “mirror 105” block filled with a Scat crank and rods and Mahle forged pistons. To that we are adding a Lunati hydraulic roller cam, Harland Sharp roller rockers, Edelbrock heads, and a factory low-riser 2×4 intake.

For a street engine, it’s respectable. For a race engine, we left a lot on the table. The medium-riser Edelbrock heads are right out of the box, while the low-riser intake gives us port misalignment that hurts to look at. Barry said the low-riser intake on medium-riser heads usually costs about 20 hp, while a basic gasket match, bowl work, and larger valves in the Edelbrock heads—“nothing crazy, just the basics”—are good for a solid 20-30 hp. Port them to within an inch of their lives and there’s even more available.

The cost of the cam, lifters, and rocker arms looks like high-end stuff, but think of it this way: The cost difference between a flat-tappet and a roller cam is several hundred dollars. The performance advantage of a roller is pretty hefty, and with the new motor oils, flat-tappet cams are not as reliable as they once were. That may be a stretch for the justification, but so be it. Keeping costs low in other areas lets you splurge on the hydraulic roller cam, and even at that, it’s not a bank-breaker.

As for the rockers, Barry has some strong opinions on the worth of factory rocker arms, none of them flattering. There’s also some concern with stock rocker shaft stands failing with high-lift cams. Lots of guys do just fine with stock pieces, but we don’t want to chance it. If we’re going to spend a couple hundred bucks on factory adjustables, we’d rather spend a bit more on quality aftermarket pieces. For hot street engines and race engines, Barry recommended Harland Sharp.

When all was said and done, our 445ci FE squeaked out 505 hp at 5,500 rpm. Our target was 500-550 hp, with a 5,500-rpm redline, so we were fairly pleased with it. The reality is 500 hp in the lightweight altered is going to be plenty fast for us. While online calculators are really only an educated guess, they give a terrific starting point for a build. By plugging in some weights we’ve found online for different components (aluminum-head FE, Powerglide, and so on), and some rough guestimates for what’s built so far (body weighs less than 50 pounds, chassis probably weighs 250, and so on), we figure the car is going to weigh about 1,800 pounds with me in it. The calculators over at Wallaceracing.com say that with a 30-inch tall tire and 3.30 gears, that combination should work out to 8.90s at 151 mph, turning 5,550 rpm through the traps.

To be honest, that’s too fast. If our guess on the car’s weight is off, running the calculations at 2,000 pounds with everything else the same puts us through the quarter at 9.25 at 145 mph.

We’ll be doing a lot of 1/8-mile racing with it too (probably more 1/8 than 1/4), and the calculator says it’ll run about 115 mph with 4.11 gears at 2,000 pounds. Gear selection is another area where the calculators come in handy. Most people automatically think higher gears in the quarter-mile for a drag car, not 3.30s. Bench racing with the guys, a lot of them thought 4.11 or 4.30 for the quarter, and 4.56 or 5.13 for the 1/8, “because that’s what everybody ran back then.” We’ll set up a pair of spool-filled pumpkins for the Mopar 8-3/4 and everything should be pretty happy.

But even within our basic parameters, there’s still room for improvement. We’re already on the waiting list for a Tunnel Wedge single-plane 2×4 medium-riser intake when the next batch is available. At that point we’d also mill the choke horns off the carbs and top them with Stub Stacks. We’re pretty confident that a relatively easy 50-75 hp could be had if we decide to go for it. We built a fair amount of compression into the engine, and the cam specs are stout, so we won’t run out of short-block. With an improved top end, the combo would still be as durable as an anvil because we won’t change the redline.

It’s there if we want it, but the fact is, I don’t think we do. With 500 reliable, pump-gas horsepower, a self-imposed valvetrain-friendly 5,500-rpm rev limit, a Powerglide, and a spool in the rear, we’ll see high 9s or low 10s, and that should be more than adequate for years to come.

And like Uncle George’s original car, we don’t foresee needing to do much more than check the plugs and change the oil. Reliable, fun times hanging out with friends at the track. Now that’s traditional!

Cam Bearing Alignment

In another life, Barry Rabotnick was a bearing guy at Federal Mogul. This gave him a little insight into the ways of Ford’s cam bearings, and he’s surmised Ford did it differently than the others, at least for the FEs.

The original Ford cam bearings were open at the ends and interlocked like puzzle pieces. The bearings were loaded onto a bar and all installed at the same time in the blocks. Then a second bar came through and clearance-bored all the bearings, essentially align-honing them. Then the cam was slid home.

The problem for builders today is that the bearings were align-honed with great precision, but not the bearing bores themselves, so the actual hole through the bearing might be offset a bit. When we install new bearings today, the holes the cam rides on might not be aligned perfectly.

Barry’s head machinist, Bill Blair, made this tool to align-hone the new bearings to the block. Basically, any shiny spots on the cam-bearing surface are scraped with the cutter, to duplicate what Ford originally did. We’re talking thousandths of an inch here.

Sources

ARP: 800/826-3045: arp-bolts.com
Canton Racing Products: 203/481-9943: cantonracingproducts.com
Edelbrock: 310/781-2222: edelbrock.com
Harland Sharp/Custom Speed Parts Mfg.: 440/238-3260: harlandsharp.com
Lunati: 662-892-1500: lunatipower.com
Mahle Aftermarket Inc.: 888/255-1942: mahle-aftermarket.com
MSD: 915/857-5200: msdperformance.com
Scat: 310/370-5501: scatcrankshafts.com
Survival Motorsports: 248/366-3309: survivalmotorsports.com

The post How to Build a 500hp Stroker FE Engine for our Altered Project, Part 2 appeared first on Hot Rod Network.

Heat robs power. With sophisticated aftermarket EFI systems like the Holley Dominator controlling ZedSled’s drivetrain and making decisions in millisecond increments, our ECU can actually dial back timing and fuel if sensors read excessively high temperatures. Excessive heat prematurely wears out components too. For example, the transmission, coil packs, wiring harnesses, and cables all suffer when temperatures exceed normal operating conditions. When dealing with the comfort level of your car and the overall driving experience, heat is not your friend. Nobody wants to be cooked out of the cabin while driving, so heat control is important in other vehicle systems as well. We’re going to walk you through some of the techniques and products we used on ZedSled, our 1978 Camaro project, to keep the heat under control and out of the car.

I-M Shield is a thermal barrier that is customizable to fit almost any surface and is adhesive-backed for permanent installation to any clean, flat surface.

Cooler air entering the engine is denser and allows more fuel to be burnt and make more power. The underside surface of our Holley Mid Ram intake is prime real estate for a heat shield.

We start by making a template to transfer to the I-M Shield.

We’ve left a half-inch extra to create a finished edge to wrap it around intake runners for better insulation—and create a tidy look.

A (sharp) single-edge razor blade trims the backing and insulation easily, while leaving the aluminum exterior intact.

The folded edge doesn’t do much other than look nice, but it’s easy to do and allows you to make a custom-fit shield that looks like a production piece.

The manifold gets cleaned with a wax and grease remover to ensure adhesion. This cleaning step is particularly important if you’re using I-M Shield on a previously installed or used manifold.

With the plastic backing removed from the adhesive, I-M Shield sticks permanently to the manifold, and we made several relief cuts to wrap the shield around the runners.

The finished installation looks great, even though it’s almost completely invisible from the top. The magic is in the insulation factor, and Heatshield Products claims as much as a 15hp gain for LS engines due to the cooler air charge.

Lava Boots can withstand 1,200 degrees F continuous heat and will protect your plug wires from header heat and spark loss due to deterioration. Plug boots are mandatory if you’re using headers.

Stealth Shield is a lightweight fabric, roughly 1/8-inch thick, that is designed to be installed under the carpet and between the headliner and roof panel. It reduces cabin heat and won’t interfere with carpet or headliner fitment or add any substantial weight.

The mat is easily cut with scissors and ours gets laid out for test-fit before gluing down.

A headliner spray adhesive works great for locking the matting onto the floor. We’re gluing ours over a spray-on sound barrier that also functions as a heat-resistant barrier to a small degree.

We’re wrapping our mufflers in Heatshield’s Muffler Armor kit, a job we start by making a template that wraps around the muffler case, then gets transferred to the armor. The aluminum shield is easily cut with a box cutter, and the straight edge ensures a precise cut.

The inside of the shield is not fiberglass, it’s a thermally stable matting that withstands tremendous heat while creating an air-gap between the heat-generating muffler and the floor. As a side benefit, it’s not itchy like fiberglass.

We removed about 1/2-inch of the insulation off the back of the shield, which allowed us to form a nicely folded and finished edge.

We rounded the corners of the shield to have smooth transitions and clean looks.

These thermal ties are made from 304 stainless steel and are available in different lengths to fit a variety of components like our Hooker Mufflers. .

After cinching the ties up, we trimmed the ends off, leaving about an inch that we looped with a pair of needle-nose pliers to lock it into place.

Here you can see the top and bottom of the mufflers, and you can see what the attention to detail creates. This DIY kit looks like a production product and will insulate the interior against heat and also reduce some of the exhaust noise entering the cabin.

Properly coated headers like these Super Comps from Hooker have ceramic insulation on both the inside and outside of the tubes, which significantly reduces engine-bay temperatures (we measured a reduction of nearly 50 degrees) as well as delivering performance gains due to more efficient evacuation of exhaust gases from the cylinders.

Controlling heat in any vehicle is a layered strategy, with each step complementing the others. Being able to install heat insulation while we assemble this car makes the job easier, but it’s never too late to insulate!

Parts List

I-M Shield: $45.00 kit
Lava Shield Spray Plug Booths: $155.00
Muffler Armor Kit: $109.00
Stealth Shield fabric: $67.95
Hooker Super Comp Headers: $740.00
Spray Adhesive: $8.00

The post How to control power-robbing engine heat, with Car Craft’s LS-Powered 1978 Z28 ZedSled. appeared first on Hot Rod Network.