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L20B .040 overbored piston ring gaps


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For an engine stock and up to high performance street applications.... top ring 0.0045" for every inch of bore, second ring 0'0055" for every inch of bore.


I assume 0.040 is in inches? So 85mm = 3.349 " + 0.040" =

3.389 X 0.0045 = 0.015.25" top ring

3.389 X 0.0055 =0.01863" second ring


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Ring gap for top ring is important. .003"-.0035" per 1 inch of bore, so for top ring, about .012" gap


Second ring slightly less.


Oil rings don't normally need to be gapped.


You can buy a cheap rotary file ring gapper from Summit or Amazon for like $15. I wouldn't order from Amazon right now with all the Trump associated USPS bullshit.

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