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Old 09-21-2012, 02:39 PM   #37 (permalink)
oil pan 4
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I think dave nailed it.
Just ran adiabatic compression for a 22:1 diesel like mine and with 0'F air the temperature in cylinder at TDC is only going to be like 860'F.
A more normal 18:1 compression diesel will only hit about 800'F.
40'F air in a 22:1 engine gives me 930'F and a 18:1 engine will hit 860'F.

The hotter the air the better, to a point.
800'F does not seem hot enough.

Quote:
Originally Posted by Duffman View Post
Our Macks at work say under hood air at -12C and winterfronts at -18C I believe.
Ok so we have Mack, cummins, Man and adaibatic calculations all saying air below 30'F isn't good and air in the >20'F range is bad.

Thats good enough for me.

Seems like we should try to shoot for <40'F IAT and keep it as cool as possible when the out side temperature is well above 40'F.
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1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
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