“There’s actually a very small combustion chamber at 46cc. It is a true hemi but basically, it’s all valve,” says Vrbancic, noting the valve sizes at 2.400 intake and 1.900 exhaust. “There is water going through the head but it’s not a conventional water jacket. It does keep them cool, though.”

Herbert also designed a custom 3-piece billet intake manifold in which the center section is actually part of the intake port, according to Vbrancic. Sitting on top is a pair of Carb Shop-prepped Holley HP carbs. Rounding the engine assembly are a Jesel belt drive, Meziere water pump and MSD distributor.

With a “small solid roller” the engine makes just over 800 horsepower at 6,600 rpm on pump gas. Peak torque was 671 lb-ft at 5,200 rpm. Final destination is a street rod.