hey guys, I have 3 sets of new piston rings and one set of old ones.. is there any ways to tell if they are good before I install the head and do a compression test.. I would really hate to put my head on, torque everything down and do a compression test to find out that one is bad and then buy a new headgasket/bolts/valve cover gasket? thanks

anyone? moderators? gurus? thanks :)

Originally posted by 420Adebt
hey guys, I have 3 sets of new piston rings and one set of old ones..

Wait. So... You have 3 pistons with good rings and 1 with bad rings?

Why the fuck did you do that?

haha, nah I bought some used pistons from mitsubishi graveyard.. then I bought 3 sets of new piston rings (from neon.org) they didnt have the 4th set, why I dont know, so that's why I wanted to know how to test them. rather than me having to buy a new set of 4

Chances are is that somebody broke a ring trying to get it on the piston and sold the rest to you. The best you can do is check the ring gap via the cylinder size. Stick the ring in the cylinder, turn the desired piston upside down, and push the ring so that it sits level in the cylinder. Get some feeler blades out and check that gap that is left in the ring. Compare that to what it should be. When I have to blueprint a motor, I always do this to be sure the gap in the ring is within specs. If the gap is too small, then it will need to be filed. If it is too large, then you are screwed, unless you like low compression and blow-by. Buy a new set of rings by the same brand so if you break one, you have extras. Chances are that you will stick that piston in the cylinder and it will not develop good compression seeing that you have no idea what happened to the motor that they came out of.

sweet thanks alot for the replies.

I wouldn't chance it I put some supposedly used but good rings in my engine and now it burns quart of oil ever 100 miles go with new set of rings, you'll be out for the 3 new rings you got but its some piece of mind. it did seal up good though but its burning oil must be the oil control rings.I guess a machine shop can check if the rings are good but it has to be cut to fit into a bore and everyone bore isn't perfectly the same.

Originally posted by 420Adebt
...then I bought 3 sets of new piston rings (from neon.org)....

How much did you pay (w/ shipping) for the 3 sets of piston rings? I checked Parts Dinosaur and the price for a complete set is only like $47 bucks (...or 47 Wendy's Jr. Bacon Cheesburgers !). I was just wondering the reason behind the purchase?

30 bucks, but they were hastings rings.. not the cheapo's

Originally posted by 420Adebt
30 bucks, but they were hastings rings.. not the cheapo's

Paying 40% of the full price for 75% of the full package. Not bad I guess, except now you're stuck with finding 1 more set.

I wouldn't use used rings, they're vital to compression.

Dont know exactly what you are trying to do here, but never put in used rings, mainly when referring to a newly honed cylinder. Just dont do that. Now if you are re-installing the SAME old rings on the same old piston, in the same cylinder, then thats ok. Fresh honed cylinders always get new rings. If all your cylinders were bored oversize, then you have no choice at all to get all new rings in the correct oversize.

Buy new rings IMO.
I tried the used ring in the same cylinder thing once and it ran rough. Never even bothered doing a compression test cause it was obviously not sealing. Pulled it all back apart and did it again with a fresh hone and new rings.
I know $50-75 seems like a fortune now, but if you have a crappy engine build you'll think 'why the hell didn't I just do it right' everytime you drive the car.

EDIT- You might try calling Hastings and see if they'll sell you a ring set for just one piston. They do it for 5 cylinder audis. :shrug

Originally posted by thedawg
EDIT- You might try calling Hastings and see if they'll sell you a ring set for just one piston. They do it for 5 cylinder audis. :shrug

Yeah, tell them you broke one of the rings and don't want to buy the entire set of 4 for just 1 set of piston rings.

good ideas thanks guys

hahah dude those were my piston rings I think...was it from neonGuy302???