so i already posted this pic but didn't get alot of replies so i'm hoping i can get some more insight this time. 7 top rings came out like this, all 2nd rings were fine. no ridge so they didn't break when i pulled the pistons. i pulled the motor due to a knock which was caused by running low on oil. a few things appeared on tear down, rocker shaft blew out a plug that lucky stayed put in valve cover. exhaust was coated with oil showing a leak was happening. when i pulled the intake, it looked like i was sucking oil but i never had any blue smoke, but chambers and piston tops were wet with oil. i drove 7 hrs each way to race in montreal with my 2.76 pumpkin and did a few passes with said ratio at 13.8 before putting in my 3.91 and going 12.9 @ 106. my friend thinks doing 3 passes with the 2.76 lugged the motor and trashed the rings. i'm leaning to detonation from sucking oil, my exhaust is loud so it's hard to hear engine sounds. it's a reringed 440 w/mvb 727 in a 3700(w/ me) b body. any help is much appreciated. (sorry so long)

definitely heavy detonation...

the 2.76 gears DID NOT cause that.....

you usually dont see a top ring shater like that.... what kind of rings are they? whats the top ring made out of? is it a cheep set posibly like a cast top ring. i see the second ring do that but not the top. is it possible when the engine was built the second and top ring got mixed up? detonation will cause this but i see it manley the second ring.

I have never seen piston rings break into so many pieces Can you take a good close up picture of one of the piston tops (broken ring one) from the side so we can see the side of the piston above the top ring? Oil will and does cause detonation What do the sprak plugs look like? Picture also

Ouch!
Detonation!
Ring grooves on piston worn (up-down) clearance to much! Lucky all the big parts are in one piece!
Good Luck!

rings weren't mixed up but they were cheap iron rings. i reringed it myself and honed it myself. they were std. size so the gaps were a bit on the big side. i had no money but was diligent and the motor ran great. i'll go out and take pics right away. i knew the 2.76's didn't cause this. i was shocked when they came out like this . thanks for the replies guys. appreciate it.

I have seen top rings do this once before with to much clearance/too thin of a ring...don't ask how I found out...

a cheap set of rings prob had a cast top ring in it an not a nodular. and its very possible if you were oiling in the cylinder and detinated it would do it

sorry i can't get any closer with my camera. the plug is showing very rich which is something i have been trying to fix ever since i had the car but that's a different topic

I sure dont see any signs of a problem in the piston
pics... doesnt even look like detonation from the top
edges but I'm not saying it wasnt that... I have seen
rings break but not like yours... just 1 break so it
has 2 parts.... and you say you have 7 pistons that
did that

Sweet Sweet Detonation.

What does the top of your intake valves look like?

I bet that the plug that poped out of your rocker shaft filled the head enough to have the oil level above the valve guides, and if thare worn and all you have is umbrella seals that the extra oil caused detonation and broke the rings.

This time maybe some better rings and maybe a overbore.

Also some guide liners and some positive seals should do the trick.

i know....what the heck? what about running low on oil? i figured the two were seperate problems but????

---

Lack of oil had nothing to do with that... 2 separate
issues... to me its a stumper

brand new source heads. haven't pulled the springs yet. going to do a stroker next have the kit and the 400 but this was my runner and i wasn't financially ready for machine shop yet. looks like my RRSP may be taking a hit soon

I had that happen one time with one piston. My wife was nagging me while I was assembling the engine, and I accidently reversed the top and second ring.

The cast scraper shattered exactly like that. You may have a set of 2 scrapers due to mismarking also.

Two things come to mind, both involve ring butting or not enough clearance on the back side of the ring. Did you remove all of the carbon in the top ring lands before installing the new rings? Did you check for back clearance on the new rings? There has to be a reason besides detonation to break 7 out of the 8 top rings, I think