When NASCAR first imposed restrictor plates on engines at the superspeedways, some engine builders made more power by reducing the engine displacement. Now there are minimum 350ci and maximum 358ci displacements for NASCAR engines to prevent teams from spending more money and experimenting with different engine sizes.

However, some racing classes with restricted intake systems don’t specify minimum displacement, and Stan Boyd at Michigan-based Engineered Victories is employing the little-engine strategy to make the most power and increase the rpm range while using the required 500cfm 2-barrel carburetor.

“An engine is an air pump, and you can only get so much air through that carb,” says Boyd, who used to race in the old Craftsman Truck Series. “Typically a 350 will run out of air at 6,600 rpm with a two-barrel. To get 8,000 or higher, one of the things I did was lower the cubic inches.”

Without disclosing his bore and stroke dimensions, Boyd says the engine is 320ci. It’s based around a Dart SHP block and topped with RHS 14-degree iron heads and RHS aluminum intake. Internals include Callies crank, Jesel rockers and a flat-tappet camshaft.”

“There’s a lot of stuff to make the cam work, different coatings, different oils and rocker ratios,” says a guarded Boyd. “In order to run high rpm you have to have high-dollar parts.”

On this dyno video the engine pulled 527 horsepower and hit 8,100 rpm.

“The class runs 8-inch treaded DOT tires, so traction is a big problem, adds Boyd. “Another reason to build small cubic inches is to take away some torque so don’t spin the tire coming out of the corner. This motor still makes more torque than [the owner’s] old motor, but now makes it at the right rpm.”

A similar engine will cost $20,000 to $25,000, but Boys says it will last an entire season without a rebuild.