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In the mid 1960’s suffering stiff competition from larger displacement stock based engines, it appeared that the old Offy that had evolved from the speedboat engine of 1926, was finished at last. A fortunate change in racing rules gave renewal to the Offy and a chance for victory as forced induction engines were now permitted. The first turbocharged Offenhauser of 1967 could put out nearly 570 horsepower at 6,400 rpm. Because of the tremendous power increase, the Offy crankcase had to be beefed-up and an oil cooler to dissipate the added heat and four short years later, with its boost unlimited by the rules, producing more than 1,200 horsepower returning Offenhausen to its winning ways.