wrote:

"Steve" wrote in message
...


I pretty much agree, although today's high-speed diesels are doing a lot
better at approchin the constant-enthalpy cycle than they used to,
thanks to being able to divorce the injection profile from crankshaft
position via electronically-controlled injection systems.


Now that you mentioned it, what sort of rpm ranges are the high speed
diesels capable of?

Well, a "high speed" diesel in the usual sense is anything that turns
more than 1500-2000 RPM. So 18-wheeler diesels (Cummins N-14, DD Series
60, etc) are considered "high speed diesels" and locomotive engines are
'medium speed." Low-speed diesels are those direct-drive 3-story tall
ship engines that turn 120 RPM max and put out 25,000 horsepower.

But there are more and more small diesels that run just as fast as
gasoline engines. There's no fundamental limit thats any different than
a gasoline engine, really, but up until now there's not been a demand
for high-RPM diesels.