Converting A Ford Flathead Four Or V 8 Engine To Overhead Valves

Converting a flathead engine (valves in block) to an overhead valve involved removing the original head and valves and installing a custom-made cylinder head and pushrods. Other modifications such as exhaust headers and pipes, intake manifold, and carburetors or fuel injectors were often required. Most conversions, including the famous Ardun OHV, moved both the intake and exhaust valves to the new cylinder head while a few only moved the intake valve. OHV conversions vastly improved the performance of Henry's flathead engines which were around 100hp from the factory. Ardun-powered dragsters and land speed cars often reached 250-300+hp after conversion and additional fine-tuning and hot-rodding. By comparison, the fuel-injected small block Chevy OHV V8 in 1957 produced 283 horsepower with much more powerful muscle cars appearing in the late 60s. Needless to say these kits were incredibly rare and expensive and are incredibly sought-after today.

If anyone is lucky and/or wealthy enough to obtain a flathead OHV conversion today then this skill is still applicable, although I would argue that working knowledge of flathead engines in general is a dying skill since they are no longer in production for automobiles. Since drag racing and land-speed racing is divided by engine types and classes the OHV-converted flathead still has a place. The overhead-valve flathead engine represents hot rodding in its truest sense by trying to squeeze every ounce of speed out of what you've got.

http://www.ardun.com/images/line2.jpg(approve sites) http://www.ardun.com(approve sites)