When the Chrysler Hemi V-8 was introduced in 1951, its displacement was 331 ci, identical to the Cadillac. Coincidence, or a shot across Cadillac's bow? Chrysler's engineering staff went Cadillac one better in the compression wars, devising a hemispherical combustion chamber that could run on regular gasoline.
409 v8 engine This is quite a unique design in that the combustion chamber is in the block and not in the head as the usual engines are. This helped in keeping ping/knock down and using high compression as the combustion chamber was cooled more efficiently.