Hi all,
Have there been different types of piston rings for the B20 engines throughout their evolution? I could get a discounted set but cannot judge if it applies to my specific application (B20E, K-jet, 8-bolt crankshaft: 1974-75, I guess). If there have been different types, what should I be looking for?
Any hints? Thanks, Séb

Last year I put new rings in a B-20F removed from a '75 240 (eight bolt flywheel). I ordered rings directly from Hastings (US piston ring manufacturer). They had different sets available for different years - I thought I ordered the right set - NOT! The ones I got were substantially thinner than the ring grooves. I ended up getting a set they had listed for a 6-bolt motor - fit just fine.

Moral of the story: measure what you have before going to order replacements, because the supplier's listing may not be accurate.

Agreed, measure what is in there! And if you are doing a re-ring "freshening" then I suggest all new bearings, glaze-break (and possibly ridge-ream) Very careful cleaning of the ring grooves and the oil return holes, new wrist pin clips (but yours is press-fit, I think) and total seal rings. total seal very nice.

mike!
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Mike!

Hello,

Yep, you always have to measure how thick the rings are.
It depends if you have Mahle or KS pistons in your engine, Volvo used them both. Always measure the bores of the engine before deciding to put in new rings. If the bores are not straight (mostly tapered), or there is an edge at the top of the bore the rings WILL break ! If the bores are not round anymore you will make things worse with just new rings. If the bores dimensions are still acceptable, hone them PROPERLY, 35°-45° angle and always use lubricant while honing. Otherwise the new rings will never run in.
To assure a reasonably short break in period use cast iron rings, not the hardchromed ones.

Best regards

Stefan