Piston ring gaps

[ajwans]

Can anybody give me some guidance on what to set the piston ring gap for 2.0S rings? Everything is Mahle if that makes a difference.

The factory workshop manual shows the ring gap to be 0.15mm (0.006") which seems a little small, not that I know more than the factory, only everywhere else I look they give a rule of thumb like 0.004" per inch.



What gives? Do we run super close rings on early cars or did the factory have a misprint in their specs?

andy

[Trackrash]

The spec is 0.006 to 0.0177". So 0.006" is the minimum allowed.

[r lane]

I might ere on the loose side. An extra .01, .02 will have 0 effect on the compression. Too tight and they touch, the ring begins to twist or buckle and lose contact.

[dannobee]

If the ring gap is too small it can pull the top of the piston right off. No, I'm not joking.

[manbridge 74]

Looks like your using factory parts and using factory specs won’t give you any issues. The spec is not a misprint, the cylinders really do expand on these.

[VFR750]

That spec is correct for air cooled cylinders.

.004/1” bore is for water cooled engines.

I did 0.008” gap on all. Just fine

[ajwans]

Originally Posted by manbridge 74

Looks like your using factory parts and using factory specs won’t give you any issues. The spec is not a misprint, the cylinders really do expand on these.

Thank you. That was the part I was missing in all of this. Our cylinders expand way more than US domestic iron/steel bores.

All makes sense now, thanks all for your comments.

andy