Inside a Keith Dorton–Built Sprint Car Engine

Asphalt sprint car racing makes incredible demands on engines, here’s how Automotive Specialists builds power plants capable of feeding that demand.

The modern Sprint Car has evolved into an incredible racing machine. They develop tons of downforce thanks to the overhead wings, have tires that create the largest combined contact patch short of a Top Fuel drag racer. On top of that, absolutely everything possible has been stripped away in the name of weight savings until about all you have left is a seat, roll cage, chassis, engine and tires. It makes for one of the greatest shows on dirt.

But things can go to another level entirely when you put a winged Sprint Car with all that that downforce and grip on asphalt. That’s exactly what the Southern Sprint Car Shootout (SSCS) does at a number of its races in and around Florida. Not all races allow the giant wings, but when they do, the action can get hot 

With all that downforce and grip at the drivers’ disposal, you’d better bet they have a keen thirst for horsepower. To find out more, we spent a few days at the shops of Automotive Specialists as they put together an all new 360 Sprint Car engine for a team on the SSCS series.

Like most Sprint Car racing series, the rulebook is relatively thin. But as far as the engine goes, rules do require 23-degree cylinder heads, mechanical fuel injection, no titanium except for valves and retainers, methanol fuel, and a maximum displacement of 366 cubic inches.  

Engine builder Keith Dorton of Automotive Specialists was surprisingly candid with the components he used in the build, including cam specs, but the dyno chart was off limits. He did tell us, however, the engine made over 700 horsepower with a strong torque curve to pull the Sprint Car hard out of the corners and maintain steam all the way down the straights. We can’t wait to see this in a race car and on the track!

Piston orentation is especially important with odd numbered valve heads.