Hello,

I suggest exhaust seats and new exhaust valves for the cylinder head along with all new bronze valve guides for all the valves.

We normally have the new valve guides machined to accept modern valve stem seals and omit the stock umbrella seals that mount on top of the valve retainers.

We used to reuse the intake valves, but having a customer suffer a failure of an old intake valve with less than 1000 miles on a rebuild has caused us to install new intake valves as good insurance on all subsequent rebuilds.

FYI, a new set of intake valves cost less than a head gasket set which was required along with the extra labor to fix the above mentioned broken intake valve.

Piston to cylinder wall clearance is .0008"-.0016"

Main bearing clearance is .0015"-.003"

Rod bearing clearance is .0015"-.0032"

AFAIK, there is no specification for out of roundness as the cylinder walls need to be near perfectly round for the piston rings to seal properly.

Are you aware that the cylinder walls should taper slightly from larger to smaller as the piston approaches the top of the cylinder?

So it is critical to make you measurements of out of roundness at the same distance from the top of the cylinder bores.





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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502