Compression ratio.

"L & D milligan" wrote in message
...

"Jacques Mertens" wrote in message
...
It would not be sufficient for a gas engine but diesels need twice the
air
of a gas engine.
If the two engines are of equal capacity and turning at the same speed and
both are say four stroke engines then why would diesel require twice the
amount of air?

"Jacques Mertens" wrote in message
news
Compression ratio.


Makes sense. But wouldn't the higher compression ratio of diesels be at
least partially offset, if not completely, by their significantly lower
operating RPM's when compared to gas engines? Seems between these two
offsetting factors, air consumption should be pretty close to the same given
similar displacement and operating duties. Just thinking out load.