Big-Block Chevy - The Pile Driver - Part 2

The Engine All that ground-pounding goodness came gratis some free-breathing induction from Trick Flow Specialties in the form of the new PowerPort 320cc aluminum heads, and R-Series single-plane intake manifold. Flowing over 360 cfm at its peak, the TFS PowerPort head could easily feed 502 hungry inches (now 509 with an overbore), but not alone. We got additional induction help from a solid-roller valvetrain from COMP Cams-principally by way of 292/298 degrees of gross duration (.020-inch tappet rise), 254/260 degrees duration at .050, and .653/.666 inches of lift. Finishing out the induction chores was a brand-new 1,150-cfm Ultra Dominator from Holley.

Although the 502 Ramjet short-block we started with was endowed well enough for a touch over 500 hp, these new free-breathing pieces would put a hurtin' on the I-beam Ramjet connecting rods, so we elected to go with some stronger Eagle H-beam rods. Lastly, the Ramjet's low-compression pistons would have to be replaced in order to capitalize on the promising horsepower potential of the Trick Flow induction. We selected a cost-effective set of SRP 17cc domed pistons in a 4.500-inch bore size. With our stock crank, these would push our 502 up to 509 cubes and peg the compression at a comfy 10.1:1. The entire package was assembled with the aid of Andy Mitchell of Outlaw Racing Engines in Upland, California.

The Challenge While hanging out at the dyno, we wondered just how much e.t. the 509 Pile Driver would be good for in a street car that was optimized for the track? It's a question we get asked a lot, especially when readers call bs on magazine dyno test results. As the saying used to go before the advent of Engine Masters, you can't race a dyno. We initially thought about dropping the Pile Driver into the Street Sweeper, our resident '68 Chevelle project car. With its bulletproof Currie 9-inch rearend, TCI Super Street Fighter Turbo 400 trans, and 28x10.5-inch Mickey Thompson slicks, it certainly has the driveline beefcake to handle the power, but without a rollcage, we'd be dead in the water. We have already been kicked out of the track twice for running quicker than 11.50 with the 496-inch Howitzer big-block, so they were on to us.

What we needed was a car that was close to the Street Sweeper Chevelle in terms of weight, equipment, and driveline, but that was more optimized for the dragstrip than our g-Machine-oriented project car. We put the word out locally, and found our guinea pig through Tim Lee, owner of Don Lee Auto Service in Rancho Cucamonga, California. Lee got us in touch with Don Gatlin of Bakersfield, California, a 42-year-old electrical contractor, who has been bracket racing steadily for 20 years. Don liked the idea, and loaned us his '71 big-block Chevelle bracket racer that also does double duty as a street car.

The Chevelle Gatlin's Chevelle has been in his family for six years, being bracket raced for most of that time, while also seeing a good amount of street duty. Gatlin's '71 is a veteran of the regional Top Comp class, having racked up numerous wins and many appearances in the finals. Normally, his Chevelle has an iron-headed 540ci big-block underhood. That mill has 12.5:1 compression, iron Merlin heads, Merlin block, and a .730-inch lift solid-roller cam. Gatlin figures that engine makes around 850 hp, but he's never actually put it on the dyno. It has, however, powered the Chevelle to a best quarter-mile e.t. of 9.98/135 with a 1.45 60-foot time. That e.t. was with a curb weight of 3,730 pounds, including the driver. It's interesting to note that with the aluminum-headed Pile Driver 509 underhood (which also sported a much lighter 502 block), the curb weight dipped to 3,642 pounds with driver, for a savings of almost 100 pounds off the nose.

With Gatlin's blessing, we enlisted the help of Tim Lee and the crew at Don Lee Auto Service to swap Gatlin's 540 Merlin for the Pile Driver. A few hours later, we hit the start button, and everything sounded perfect, just like it did on the dyno.

With jet extensions installed and a slight adjustment to the needle and seat of the rear float bowl, Gatlin went back for his first round of eliminations. We agreed to dial the car hard with a 10.60, hoping we'd feel good if we broke out. We had this one last chance, and the Pile Driver needed to produce!

Without changing the setup to the tire pressure, shocks, launch rpm, or the 6,600-rpm shift point, Gatlin did his burnout, staged it, then let it fly. Once again, the front end stood up, but no bog this time. Everything sounded fine down track, and Gatlin lit up the scoreboard with a losing 10.608 at 128.46. Don redlit by two hundredths, but otherwise ran dead-on his 10.60 dial-in. Unfortunately, losing means we had no more runs left. Nevertheless, we got the TFS-equipped Pile Driver down into respectable 10-second territory, and proved that every pony we made on the dyno got put to the tire!

BY THE NUMBERS