Diesel engine "compressor", what is it?

[jimbunyard]

Originally Posted by a64pilot

Turbo lag isn’t the issue, the issue is that the turbo won’t begin to make significant boost until X RPM, and you can’t get to X RPM until after you get onto plane, but need the extra HP to get there.
Classic example of being behind the power curve.
A supercharger gives you power now, boost is there, always.
I’m surprised at the complexity of a compound engine though, especially if the Supercharger actually disconnects.
The advantage of a Turbo is it’s more efficient, it uses “free” energy from the exhaust, where a Supercharger steals crankshaft power and therefore is less efficient, however the decrease in efficiency isn’t all that much and isn’t worth the complexity of a compound engine in my opinion.
I have never seen a blower that is disconnected, I didn’t think that was possible, they are positive displacement pumps, if it doesn’t spin, air doesn’t go through it, so there must be an alternate air path too?
Unless it’s a centrifugal blower?

I'm going from memory here, but if memory serves, yes there is a bypass when the blower (double rotor, twin lobed, Roots style) disconnects.

You think that's complicated, how bout this:





4 turbos, 2 blowers, 149 cu in per cylinder, rated 1600 hp continuous duty. An indication of how highly tuned these dinosaurs are, the cylinder under the black exhaust manifolds is the oil cooler...

[zeehag]

Originally Posted by newhaul

zee that was solved with 12v refrigeration compressors.

guess what... mighta been solved but there are still some that have not been yet changed out. and others with different priorities.