Period-correct L88 Big-block Dyno’d; Going in Falfa ’55 Recreation

The story behind this L88 clone is much more than just a big-block Chevy fan fulfilling a youthful fantasy on the dyno. This engine will be part of what arguably can be described as the most faithful recreation ever of the iconic Bob Falfa ’55 Chevy from “American Graffiti.”  

“It’s as real an L88 as it can get today,” owner Alex Ipiotis tells EngineLabs. “About the only part not stock or original are the pistons.”

The L88 boasted a stout 12.5:1 compression ratio, which is unthinkable for a street engine today, so finding suitable pistons was a chore. An original and correct “512” cylinder block had to be poked out .060-inch to start the project, so even if a set of NOS pistons were available they wouldn’t fit.

“It was a tremendous amount of homework figuring out what would be the best piston,” says Ipiotis, who worked with a devoted Chevy parts collector and a Connecticut engine builder to assemble the legendary Rat motor that was offered in the 1967-’69 Corvette. “It’s difficult to build a high-compression engine with the pistons in today’s market — when you’re not building a stroker or a big cubic-inch engine.”

The team settled on a set of Ross pistons with 51cc domes and mated them to a refurbished L88 3.760-inch-stroke, 5140 steel crankshaft and original 6.135-inch connecting rods.

The heads are the aluminum “074” open-chamber units with 2.19/1.88 valves, and Ipiotis also scored a NOS solid-lift set and NOS camshaft (PN 3925535) with original 354/360 advertised duration and .540/.560 lift.

Rounding out the L88 up top is a “198” aluminum manifold and date correct Holley 850 cfm 4-barrel carb.

Dyno numbers

Musclecar engines from the late ‘60s are notorious for sandbagging the horsepower numbers — mostly due to skyrocketing insurance rates for customers and internal “no racing” policies at some manufacturers. The 1969 L88 was officially rated at 430 horsepower at 5,200 rpm (SAE gross) with peak torque of 460 lb-ft at 4,000 rpm. Note that the horsepower reading was taken at a noticeably low point in the power band, and those engines came with rather restrictive exhaust manifolds. Basically, GM engineers didn’t lie, they just didn’t tell the complete truth.

Ipiotis took his newly minted L88 to Carlquist Competition Engines in Connecticut for dyno runs. As noted in the video description, the big-block cranked out 557 horsepower at 6,500 rpm on Sunoco 112 race gas, 2.125-inch headers with mufflers and 36 degrees timing.

The engine will sit in a ’55 Chevy modified to duplicate the black 2-door 150 driven by Harrison Ford in the movie “American Graffiti.” The car was one of three ’55 Chevys originally built by California hot rodder Richard Ruth for the 1971 classic “Two Lane Blacktop” street-racing odyssey. The main car had an L88 engine, which was beefed up with a tunnel ram manifold, while the other two sported 454 crate engines. The L88 car was then painted black, given a smaller hood scoop and a conventional 4-barrel intake for shooting “American Graffiti.”

Ipiotis’ recreation is a complete build from the ground up, with Ruth handling much of the design and consultation.

“We flew Richard out to Kentucky where the car is being built,” says Ipiotis. “We already have the Ruth front end in the car. He’s working on the firewall, the ladder bars — everything is Ruth built. A lot of homework has gone into this project.”

About the author

Mike Magda

Mike Magda is a veteran automotive writer with credits in publications such as Racecar Engineering, Hot Rod, Engine Technology International, Motor Trend, Automobile, Automotive Testing Technology and Professional Motorsport World. He was the editor of four national automotive magazines, including Chevy High Performance, and has authored hundreds of automotive technical briefings. In covering nearly every type of motorsport, Mike has collaborated with many of racing's top engine builders and factory engineers.
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