Paul
Typically,
how much boost does a turbo diesel run----say

in a marine application pushing

90 ton boat or a semi truck ccarrying a load

?

bill

I don't have the foggiest. Hold on I will look
it up in Taylor.
Here it is.

A four stroke turbo charged diesel engine with
a pressure ratio
of 2.65:1 operating at a piston speed of 2000
ft per minute has
a bmep of 217 psi and a BSFC of 0.34. Roughly
25 psi boost
if I am reading it right. Volume 1 page 479.

Pressure ratios can run up to six for some
engines like a 2 stroke Napier
Nomad with a bmep of 250 psi. That had an axial
flow compressor.

Curve 1 is for turbo charged engines.
Curve 2, interestingly enough, is the for the
Caterpillar arrangement
where the turbo charger is geared to the output
shaft like I just mentioned.
A simple supercharger type is not on this chart
for some strange
reason. These are all intercooled of course.

Cummins runs some what higher piston speed with
lower bmep
I think. This was in the late 80's.

Paul Lamar

Thanks Paul

The reason I asked is That I saw a 2 stroke turb and supercharged engine on
the net from ZOCHE in Germany. They will have 2,4 , and 8 cylinder ( radial
engines, hopefully certified by 2004 according to their web site ( I have been
aware of them since 1988 ) but one never really knows. In their spec section,
they state an intake manifold pressure of 87" Hg or roughly 3 bars.
Seems like very high pressure to me, but what do I know.

Bill

Don't hold your breath. They have been at OSH for the last ten
years and each year it will be available  next year. Vapor wear.
Last rumor I heard was they were scamming the Austrian or the German Gov.
I just wonder where they come up with the money to attend
OSH with a booth each year. No visible means of support.

The big interest in aircraft diesel in Europe is tax policy.
They tax the hell out of auto fuel ($5 to $7 a gallon.) but not
diesel fuel as that would damage the economy.

We have something similar here in the states. If
you have a farmer friend you can get farm diesel fuel sans
the tax for your Czech PT6 copy turboprop engine for about
86 cents a gallon. Course that does not do you any good when
you are on a long cross country flight.

Paul Lamar

Yes , I know,,,saw them at OSH 1988, and 1990.

Hope springs eternal

bd

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