Compression Test

[ZeroKnowledge]

before I do a full rolling road session I have done a compression test on the engine.(using sealey VSE300D)

haynes manual states it should be 11-13 bar

 

first results on hot engine with all plugs removed showed all cylinders were around 6 bar, then I remembered

that the throttle should be wide open.

 

2nd results were between 15 & 16 bar.

 

as the head has been skimmed would this account for higher than spec pressure??

[Snapperpaul]

A head skim will increase pressure so will a thinner head gasket but not by loads unless you skimmed 1mm or more

Cam timing makes a difference, inlet valve closing late, exhaust valve closing late all make a difference.

A performance cam will give less compression due to more overlap

[Foz]

As I understand it, there are loads of things that affect the actual pressure you get, but as long as all 4 cylinders are pretty much the same as one another there's nowt to worry about !