2-Cycle Engines

[Red Byrd]

Quick question (although more may follow...)

When was the last 2 cycle engine entered to race in the Indy 500/Nat'l Championship?

Thanks to all who reply!

[midtown]

Was the Cummins Diesel in '52 a two-stroke?

[ZOOOM]

IIRC the Cummins engines are two stroke diesels. If I'm right then all the Cummins race cars were two strokes.

The Detroit Diesels are four strokes, as are most diesels.

[Gerald Laurie]

You got that backwards. Only the latest Detroits are four strokes. All of the older engines were two strokes and used a blower to pressurize the airbox and the air entered through the crankcase. Of course the fuel was injected. Any Detroit you see with a roots type gear driven blower are two strokes. Some have a turbo on top of the roots blower for more power, but all of the the detroits with a roots type blower are two strokes.

All of the Cummins Diesels have been four strokes. Detroit went to four strokes because they couldn't make the two strokes meet emissions standards