Formerly of the GM Heritage Museum, the tube-chassis car raced in the 1985 and 1985 IMSA GTU class, taking on RX-7s, 911s, and a slew of Nissan Z cars.
Just like the base-model production Fiero, you’ll find a four-cylinder pushrod engine mounted just behind the cabin, but its basic configuration is about all it has in common with the lame factory Iron Duke. This machine is powered by a 3.0-liter Pontiac Super Duty four-cylinder with Kinsler fuel injection.
The SD4 engine was often used in drag and oval-track racing, but really shined in IMSA endurance racing. Never offered for sale in a production car, it did make an appearance in the three Fiero pace cars used in the 1984 Indy 500.
The engines were made with racing in mind and were essentially half of a V-8 and could be had with different head bolt placement to accept a Pontiac Super Duty or Chevrolet small-block cylinder head. That meant that high-flowing, spread-port, canted-valve heads could be used to produce well over 400 horsepower using displacements at least as high as 3.5 liters, although we imagine the vibrations from a four-pot that size would have tried to shake every fastener out of the car. There’s a reason why production four-cylinder engines rarely approach 3.0 liters and when they do, they typically employ balance shafts.
Kinsler still produces the intake manifold used on this engine, and while electronic injection is now available, we’re betting this one is mechanical injection. Mechanical injection and huge throttle butterflies are not known for part-throttle drivability, but this engine would no doubt make some great sounds at wide open throttle. A provided video gives some idea of the sound—we bet it’s even better from behind the wheel.
Like its production brethren, this mid-engine racer seems like quite a bargain. With 12 days remaining to bid, this class-winning car is priced far less than the sum of its race-bred parts. Just imagine posting a better lap time than some mid-six-figure exotic with this eight-valve hot rod. You couldn’t put a price on that, but it has to be worth more than $8500.