1,450HP, 299ci, Short-Deck, Small-Block Chevy
Ron Main and George Poteet, Saticoy, CA
Bonneville racing is all about heavy doses of reliable horsepower. Decades ago, it took four supercharged engines in a streamliner to even consider going 400 mph. Now, Ron Main and George Poteet are planning an assault on the Salt pushed by a tiny, 299ci, small-block Chevy built by legendary turbo-engine master Kenny Duttweiler. The engine is specifically built to run in the Main & Poteet Speed Demon car that claimed fame as the first flathead-powered car to break 300 mph. Next came a Duttweiler-built Mopar four-banger Midget engine, followed by a turbocharged Duttweiler-built 2.2L GM Ecotec four-cylinder that set an SCCA record at 343.494 mph in 2008, running 390 mph out the back door. Duttweiler says this newest engine should put them close to their goal of 430 mph. That's 630 feet per second or more than the length of two football fields every second. At that speed, don't blink or you'll miss it all.
That's a Hogan sheetmetal intake manifold plumbed with a 90mm Wilson throttle body. The V-band clamps are an absolute necessity on the inlet side, since the turbo is capable of 50 psi. Fuel pressure is also critical because the pump must be capable of maintaining adequate pressure above the boost level.
Look carefully and you'll notice a pair of 160 lb/hr injectors per cylinder. This is so Duttweiler can run the engine on either race gas (a conservative 1,211 hp) or methanol. To put that injector size in perspective, one of these 160 lb/hr injectors could easily feed a stock TPI 305 small-block Chevy. If all 16 injectors ran at 100 percent duty cycle, they could squirt nearly 400 gallons of fuel per hour. The MoTeC electronics package is also capable of running a distributorless ignition system with the MSD coils mounted on those Rat-sized valve covers.
C. Water-to-Air Intercooler
What you can't see behind the engine is a rather large water-to-air intercooler that reduces the discharge temperature out of the turbocharger. The rule of thumb is that for every 10 degrees of inlet air temperature reduction, power goes up 1 percent, so you can see why intercoolers are important.
The engine is purposefully compact to fit inside the Speed Demon's streamliner body. The Turbonetics 117mm (4.6-inch) turbo is mounted behind the engine. Duttweiler says he twisted the turbo up to 20 psi to make the 1,450hp number. "One pound of boost is worth about 60 hp," Duttweiler says. The Turbonetics compressor map indicates that this turbo can deliver up to 50 psi, which means an additional 10 psi would be worth another 600 hp and there would still be room for more. Keep in mind that the car ran 390 mph pushing only 1,050 hp last year.
E. Heads and Valvetrain
This looks like a baby Rat because those valve covers hide a set of Dart Little Chief heads with large, 235cc rectangle ports and monstrous 2.30/1.55-inch valves. The block is designed to employ a 55mm cam core to allow Duttweiler to use a relatively short-duration camshaft that still pumps out almost 0.850 inch of valve lift using mild 1.62:1 rockers. Duttweiler says, "The lobe lift alone is more than a half inch."
These strange-looking headers were built by Steve Watt and are dictated by the limited width of the streamliner body. The heat shields are made of Inconel and are 3/8 inch thick to prevent heat damage to the body. According to Dutttweiler, right after a full dyno pull, his heat gun registered only 170 degrees F on the exterior of these heat shields. The streamliner's shell also features an inner lining of this same material.
You have to look closely to see the 8.5-inch-deck Dart block buried under all the other internal combustion accoutrements. There's also a Crower steel 2.8-inch-stroke (yes, that's right) crank along with steel Crower rods pinned to a set of Diamond 9.5:1-compression pistons. With a large 4.125-inch bore, this computes to only 299 ci.
H. Motor Plate
Duttweiler says the team plans to bring last year's Ecotec engine and this Dart small-block to the Salt. The key to being able to swap between the two engines is that many of the ancillary components are bolted to the front motor plate that is designed to accommodate both engines. This makes the chassis very modular, allowing the crew to swap from the V-8 to the four-cylinder in less than 90 minutes.
I. Cylinder Pressure Sealing
You would think with all this horsepower that Duttweiler would have to jump through all kinds of flaming hoops to get the heads to seal to the block. The truth is, he bolted on a set of off-the-shelf Fel-Pro multilayer steel gaskets and dropped the heads in place. It was that simple.