LNF full manual

JBINTX

Goblin Guru
Does anyone have the correct pressures for a LNF cylinder compression check? I have found all kinds of numbers quoted on other forums, but none referencing GM explicitly.
 

Gtstorey

Goblin Guru
I can see if the service manual has any numbers this evening. I really thought that it was all fairly close for all gas engines.
 

Desert Sasqwatch

Goblin Guru
GM Authority (.com) states the LNF is 9.2:1 CR. Wikipedia corroborates the 9.2:1 CR for the LNF.

LDK engines are listed as 9.2:1 CR in both places.

From everything I can locate, in multiple forums on several Ecotec web pages, a cold crank compression ratio (2-3 engine rotations) is stated as 160-175 on a 'new' (crate) engine tested with no or low miles.

A quick calculation for a 500cc cylinder that is compressing ambient air to 9.2 times atmospheric pressure results in approximately 130 psi. But this doesn't account for the dynamics of a motor or a combustible air/fuel mixture.
 
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Goblinfanclub1234

Well-Known Member
make sure to adjust compression for altitude also...I am a 6,600 ft...my compression numbers were garbage by regular standards haha!!
 
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