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1971 Blown Chevy Nova - It's Not Easy Being Green

Robert Mix's E85-Powered Blown '71 Nova

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Tech Notes

Who: Robert MixWhat: An E85-powered '71 Chevy NovaWhere: St. Paul, Minnesota, home of the Car Craft Summer Nationals. Please attend in 2008.

Engine: Rob bought the short-block from Ron Flood at Cedar Machine in St. Paul with Eagle rods and a set of Speed-Pro flat-top pistons that would give him 10.5:1 compression with the Dart Pro 1 215cc heads. He decided to use this compression ratio so he could run the car on regular fuel if the E85 experiment didn't work out. The cam is a Comp Magnum grind that isn't necessarily designed for boost with 244 degrees of duration at 0.050 and 0.501 lift. Rob picked it for a naturally aspirated engine with a thumpy idle and a lot of lift and duration to match the 3.73:1 rear gears and converter he'd already chosen.

Induction: Originally he had a Victor Jr. intake manifold with a Proform 750 carb. It was successfully running on E85, but no one noticed. "It didn't have the eye candy," Rob says. He knew he could cover the extra squeeze with the high-octane rating of the E85, so he called Bill Dyer of Dyer'sBlowers. Bill and Rob worked for about six months to decide how far they could push the car in terms of the limits of the fuel and cylinder pressure. Rob ended up with a bunch of different pulleys, and on the dyno they found a sweet spot underdriving the blower 19 percent and building 9.5 pounds of boost. The combination has dynamic cylinder pressure equivalent to 16.0:1 with the blower at 9 pounds and a 10.5:1 static compression ratio. Rob says that the baseplate on the blower gets so cold that the moisture from condensation will end up on the windshield as you drive, even on a warm summer day.

Carbs: He started with a Holley 750 HP and increased the main well size and the idle circuits. The corrosive nature of the E85 ate a lot of parts that were weakened and exposed from the experimental drilling. Rob replaced the HP with a Proform carb for more tuning and eventually came up with his own version of the 750 Proform carb he currently uses.

Ignition: After the blower was installed, Rob added a 6AL box and MSD distributor with a vibration-resistant coil. "With that kind of horsepower, you find the rev limiter real fast."

Exhaust: The 383 and the blower liked a set of generic 171/48-inch headers with 2.5-inch exhaust tubing, and a set of 3-inch Flowmaster mufflers on the dyno. So he copied that on the car.

Drivetrain: The green car had a TH350 built by La Vang at local shop V-Auto with a 3,500 Hughes converter. After the decision was made to take the car on the road, Rob installed a 700-R4 and upped the gas mileage from 8 to 10 mpg, even with the addition of the blower. The rear gear was originally a 2.41:1; Rob upgraded to a Richmond 3.73:1 and a set of Strange axles.

Wheels: In keeping with the almost-stock theme, Rob left the Chevy Rally wheels and added 215/60R15 and 235/60R15 BFGoodrich rubber.

Interior: The interior went from green to black in Rob's garage with the help of Year One bits and pieces.

On The Dyno: The engine made 703 flywheel horsepower at 6,500 with 600 lb-ft of torque from 4,500 to 6,500 rpm. All on pump E85 and boost.

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