Smallest diesel?

Thanks. I stand corrected.

Dan

Ed, someplace a long time ago I saw an analysis of how small a diesel could be made using conventional diesel engine technology, I.e. just shrinking existing diesel engine designs. IIRC it wasn't a whole lot smaller than the 170cc engines that exist today.

If you are willing to change fuels, insulate the piston top and combustion chamber and deal with some other problems, then smaller diesels could be made. I would guess there isn't enough of a market for miniscule diesels to make it worth while to go smaller than 170-200cc.

I Googled the topic and couldn't find any reference to the paper I saw about smallest diesels.

Dick

Dan_Thomas snipped-for-privacy@yahoo.com (Dan Thomas) wrote in news: snipped-for-privacy@posting.google.com:

There used to be diesel's down to as small as .01 cu, had an english one of

1/5 cc as a kid on a freeflight 'plane. Used a mix of castor oil and kerosene plus a sniff of Amyl Nitrate to smooth ignition. Had a needle valve venturi for a carb and a turn screw on the head that raised or lowered a piston in the head to alter the compression.

Those are compression ignition engines, but not diesels. In a diesel cycle engine fuel continues to be added after combustion starts. It's a completely different cycle.

Dick

As often happens, someone just asked me a question that I couldn't answer and it got interesting as I learned more. I'll bet that either the SAE or MIT's engine lab has published something about it. As I make up my Christmas list of SAE books today, I'll take a look.

Ed Huntress

Surplus Center in Lincoln, NE has had some smaller 1 and 2 cylinder units, 2-3 HP on up. I think they've finally got a web page out there now.

Stan

I found their web page at, cleverly enough at:

It doesn't list the engines you mentioned, but thanks for mentioning that they have a web page now. That's a keeper.

Dick