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compression

Posted: Wed Aug 24, 2016 9:38 pm
by 73sprint
I think the sprint head i am rebuiding has been skimmed twice. It measures 119.6 mm from the cam journal to the head face. What happens if it runs with too much compression ? All standard sprint engine and carbs by the way.

Re: compression

Posted: Wed Aug 24, 2016 10:21 pm
by soe8m
More hp.

Jeroen

Re: compression

Posted: Fri Aug 26, 2016 10:07 am
by Jon Tilson
Risk of detonation and piston failure...

Very common on Sprints especially with modern fuels and hotter climes...

Use a thicker head gasket. Be very careful with ignition timing and listen for "pinking" when running.

Jonners

Re: compression

Posted: Fri Aug 26, 2016 2:02 pm
by soe8m
Skimming in total 1,5mm of the head and engine deck together makes me use octane 98 at a minimum. When a head is skimmed the normal way 2 times i would not worry. If the engine then pinks there's something wrong with your mixture or you have ignition wear. My advise would be use a normal gasket and enjoy the few hp's more.

Jeroen