I2
Enzo Ferrari and Lampredi were interested in creating extremely reliable engines for racing use. In 1955, after seeing the success of Lampredi's straight-4 engines, the pair considered a straight-two engine for the slowest racing courses. Lampredi built a prototype with 4 valves per cylinder and 2.5 L (2493 cc) of displacement. It produced 175 hp (130 kW) on the test bench, but broke the crankshaft due to poor balance. The project was shortly abandoned in favor of more-conventional I4 engines.
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