There’s something alluring to a small group of racers about the path less traveled when they’re building an engine combination. Maybe they’re seeking a challenge or see a way to get a leg up on the competition, but they always find a way to bring something unique to life. Pat Donovan took a non-traditional path, and it led to his wild 632 cubic-inch Batten B4 engine combination.

The Batten B4 that powers Donovan’s Top Sportsman Firebird is a wild piece of engineering. This big-block uses a total of four overhead cams and four valves per cylinder. Fueling the engine is a mechanical fuel injection system that Donovan has put a lot of time into developing. It does an excellent job of keeping the engine fed, happy, and running consistent times at the track.

If Donovan wanted to, he could spin this engine to an insane 17,000 rpm, but he only pushes it to around 7,000 rpm to keep maintenance demands low on the mill. At that rpm level, the engine makes around 1,400 horsepower, and that rockets his Firebird deep into the seven-second zone at 180 mph.

Behind the B4, you’ll find a Torque-Drive unit that Donovan designed and built himself. This drive unit allows Donovan to mate a torque converter to a Lenco transmission. Moving to this combo allows Donovan to optimize the power his B4 makes while still having the benefits of both an automatic and manual transmission.

There are so many cool details about this engine and how it landed in Donovan’s possession. You’ll want to check out the video on the Dragzine YouTube channel where Donovan goes into more detail about this totally badass Batten B4 engine.