Depends how much needs to come off before you can decide how much, if any, shim to install. It’s difficult to calculate how much the compression ratio will change, but if your only skimming a couple of thou off it’ll not make any noticeable difference. You’d need to measure the volume of space to calculate the comp ratio but to put it into perspective, a 20 thou skim on a particular 2.5l engine I’m working on will increase the comp ratio from 10.5 to 1 up to approx 10.6 to 1. You shouldn’t need anything like that.
and I’ve skimmed a few myself
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Most of the old school diesels are flat faced heads and flat top pistons so compression hikes through skimming are negligible, the only danger of a monster cut off the head face would be valve to piston clearance.
Bob
I don't think the words performance and Perkins diesel engines, crop up in the same sentence often.
I liked the P6, good solid engine.
I’d like one of those for exhaust manifold s
Have the gaskets blown ?Hi
My perkins v8 will need its heads skimmed presumably as i need to do head gaskets . So i presume you need thicker gaskets ? How you you know what ones etc.
I have never had it done before.
Thanks
Don't you measure the the height of the piston at TDC, to the engine block, to establish head gasket thickness?
What some mechanic taught me when rebuilding old BMC's.