An Offenhauser engine no less.   The Offenhauser Racing Engine, or Offy, is a racing engine design that dominated American open wheel racing for more than 50 years and is still popular among vintage sprint and midget car racers. the 270 cu in (4.4 L) was a DOHC naturally aspirated 4 cylinder racing engine with a 15:1 compression ratio. Look at the massive brakes.