If you bleed Chevrolet orange, there are some select phrases that ring that tuning fork in your loins-ZL-1, Yenko, L88, Stinger, and 427, just to name a few. In the late '60s, Chevrolet's ammunition in the horsepower wars was a 500-plus pound killer that was chock full of compression, cam lift, and carburetion. Atop this list was the undeniable presence of the 427 L88s that were snuggled up inside the '67-'69 Corvettes.
Rated at 430hp from General Motors, one could drive directly off the showroom floor to the strip and smoke the tires all the way down the track to the tune of 118-plus mph after proper preparation. In the hands of the great tuners of the era, with drag slicks and headers, low 11s were within reaching distance. It was a great time to be a gearhead, with the Big-Three brawling it out across the country
Today, NHRA Stock Eliminator is one of the few havens left for fanatics to witness V-8 American muscle tearing up the 1320. A simple walk through the pit lanes at an NHRA event will find you rubbing shoulders with Hemicudas, GT-500s, Corvettes, Camaros, Novas, and a laundry list of big- and small-block combinations from yesterday and today.
The story begins with a two-bolt main 454ci siamese truck block bored .060-over to 4.310-inch by the man, the myth, the legend, Charlie Weston of Weston Machine of Piscataway, New Jersey. Many of the top NHRA racers use Charlie for their engine block machining. After a thorough cleaning, the assembly process begins with a stock, machined 427ci crankshaft weighing in at a substantial 75 pounds.
Over the years, rules have changed for many reasons, especially when dealing with the lack of available engine parts. Let's face it, few can afford to collect high performance parts from the '60s and risk breaking them, especially when only a handful were produced in the first place. On the Bowtie side of things, GM Performance Parts has you covered with its full line of class-legal reproduction and aftermarket engine components.
We visited Steve Ficacci Racing Engines to check out what was being deep fried over the winter and came across a bare, steel Chevrolet big-block that was destined for greatness. Built for Joe Fasano's AA/SA '69 Corvette, this block would be the starting point for a reproduction engine unlike most, but faster than all-the 427 L88.
Everyone agrees that the factory 430-horse rating was a joke; perhaps a number taken at an rpm well below peak horsepower. Regardless, this build shows there was a lot more inside that legendary mill. The end result of our build was 650 flywheel horsepower and the quickest Stock Eliminator pass in NHRA history.
Follow along and learn how to build one of the baddest of the bad.
A great deal of horsepower can be found in the camshaft geometry. Stock lift is mandated for all Stock Eliminator competitors but not duration, overlap, or profile. We went to Bullet Racing Cams for this piece, providing .560/.580-inches of lift and a duration of ... so sorry. This is one specification the engine builder was sworn to withhold by the car owner. Realistically, there are probably 500 better modern cam profiles if you're not building an L88 to Stock Eliminator specifications. Think of the possibilities if you're not hamstrung by stock lift or a flat-tappet profile.
Next, the CP piston/Manley rod assembly is cleaned and painstakingly filled with the ring pack. Much of the horsepower found in the L88 engine over the 427/425hp engine of the time is courtesy of the piston design. Providing over 12.7:1 compression, the ZL-1/L88 piston is the biggest to ever come out of a General Motors plant. Even compared side by side with the 427, the difference in dome size is easy to see.
The 401 aluminum heads (PN 12363408) are listed on the GM Performance Parts Web site as the NHRA-approved engine parts for the motor they were building. According to the class rules, no porting of any kind is allowed, though you are permitted a 3-angle valve job. Steve installed spec valves measuring 2.19/1.88 and stamped steel rockers. It's not a pretty sight when one of these breaks at 7,500 rpm, but the rules stipulate the use of these antiquated lumps of coal.
Prior to assembly, the cylinder heads take a trip to the flow bench. Although they are from identical castings, no two sets of cylinder heads flow and perform identically. Flow is measured at every .100-inch and then at the max lift of .560-inch on the intake and .580-inch on the exhaust. On these heads, one can expect them to flow over 300 cfm at .500-inch lift on the intake.
There are enough mountains that need be crossed when building horsepower in such a competitive class. That is why ARP bolts are used to keep the crankshaft and heads in place. No need to take any chances with stock or discount bolts/fasteners. Here, thread sealer is being applied to the threads prior to installation of the cylinder head.
Here we see the short-block with "ZL-1"-stamped CP Pistons ready to be closed up.
The installation of the cylinder heads (once they are assembled) is pretty straightforward. They get torqued in a circular pattern from the center outward in stages (40 lb-ft, 55 lb-ft, 65 lb-ft) to ensure an equal torque on all head bolts.
The intake manifold (PN 19131359) is right out of the box from GM Performance Parts. Side by side, you can see the precision that GMPP puts into creating an exact replica. The black manifold on the right is the GMPP reproduction, while the original, on the left, is a bonafide piece of Chevy horsepower history.
The heads and gasket go on dry, as does the manifold with a bead of silicone on the front and back of the block. This manifold was being dry fit before paint.
After a leakdown test and five quarts of Joe Gibbs Driven break-in oil, the L88 was trucked to B&B Performance Machine in Rahway, New Jersey, to be let loose on the dyno. Steve Ficacci said he has had great success with Joe Gibbs Driven products and finds they protect engine vitals-especially crankshaft bearings-as well as make excellent power.
After the engine is placed on the dyno, the race-prepared OEM 850-cfm Holley carburetor is installed, as is a set of 21/8-inch Hooker headers. For all the dyno runs, VP Racing Fuels C12 race gas was used. Most racers tend to use jet sizes up in the 80s for optimal horsepower in the quarter-mile. For our test, we started the day with 82s and tuned from there.
Once satisfied that the engine was running optimally, we went for broke. Joe Gibbs XP1 5-20 racing oil and a new filter were installed and the L88 was wound up to 7,500 rpm.
L88 Dyno Pulls
Max horsepower was 650 at the flywheel at 6,500 rpm, and the torque was still climbing down in the 5,600 rpm area. Peak torque was 580 at 5,100 rpm. On the track, these engines never see rpm less that 5,500. The best result was achieved with 84 jets.
What is the end result? Only the quickest car ever to run NHRA Stock Eliminator, with a best pass of 9.747 at 136.91 mph and a 9.814 at 134.73. This was good enough to make wheelman Steve Calabro (near lane) the fastest man on 9-inch tires.