This engine by Peter Krukowski is based on the widely acclaimed fabricated model design by Ron Collona. Some of the changes were suggested in Collona’s book -  especially for sealing the cylinder head.

Main bearing assemblies were also altered from fabricated face mounting assemblies to cylindrical assemblies assembled on the crankshaft and slid into the crankcase from the flywheel end. There are also minor revisions to the oiling sytem, magneto and water pump.

The Offenhauser engine, familiarly known as the ‘Offy’, was an overhead cam monoblock 4-stroke internal combustion engine developed by Fred Offenhauser and Harry Arminius Miller and originally sold as a marine engine. In 1930 a four-cylinder 151 cu in (2.47 L) Miller engine installed in a race car set a new international land speed record of 144.895 mph (233.186 km/h). Miller developed this engine into a twin overhead cam, four-cylinder, four-valve-per-cylinder 220 cu in (3.6 L) racing engine. When both Miller and the company to whom he had sold much of the equipment and rights went bankrupt in 1933, Offenhauser bought rights to engines, special tooling and drawings  and he and other former Miller employees took over production and further developed the Miller engines into the Offenhauser engines.

In 1946, the name Offenhauser and engine designs were sold to Louis Meyer and Dale Drake. It was under Meyer and Drake that the engine dominated the Indianapolis 500 and midget racing in the United States. the Drake family designed and refined the engine until its final race days.

From 1934 through the 1970s, the Offenhauser engine dominated American open-wheel racing, winning the Indianapolis 500 27 times. These photos are from the MEWS archive.