Yes, you read that title right. Five years ago, we published an article on a V4 small-block Chevy engine that runs on nitromethane. “But Chevy never made a four-cylinder small-block,” you say. And that is a fact. However, in the world of chasing land-speed class records on dry lakes, almost anything goes. As evidenced by this little spinner.
From the outside, ignoring the induction system, the engine doesn’t appear to be anything out of the ordinary. Once you notice the induction, though, you start to pick up on some clues, like only four air horns on the Hilborn mechanical fuel injection. Not four horns each feeding a pair of cylinders, mind you, but four distinctly individual horns with four cylinders blanked off with billet plates. Because it’s no longer a V8, but rather a V4.
Once you pop the valve covers off, things also look odd, as each cylinder head has a full compliment of valvetrain, but half are aluminum roller rockers, and half are stamped stee stock rocker arms. That’s because only four of this small-block Chevrolet’s cylinders have pistons in them. This is in order to meet the class displacement limit of 122 cubic inches, which still was not an easy task. The shortest stroke possible without going to a custom crankshaft sat at 3.00 inches.
So, that forced the combination’s bore to shrink to 3.562 inches for 119 cubic inches of total displacement. With 5.700-inch connecting rods, that meant a custom piston with a tall compression height. But, at the end of the day, a piston is the cheapest part to have custom-made, so a set of custom pistons was used to make all the math work out.
This crazy V4 engine is an absolutely awesome example of ingenuity and thinking outside of the box. Almost none of what is done to this engine makes sense when looked at, without applying the “because land-speed racing” filter on it. To read the full article on this cool little engine, you can check it out here.
