Thread: Piston scuff and cracked Darton sleeve

Update: Pulled the motor apart this week end. All wrist pins perfectly in tact. Can't see any real reason for the problem aside from the cracked sleeve itself that is protruding a little. The piston ring is slightly damaged where it ran over the crack but the rings themselves are fine, as are the ringlands. Pistons have no damage on the skirts or anything. So I guess this one will remain a mistery.

That's disconcerting.

It was detonation.

Indeed. Regular 15w40 shell mineral oil for break in.



Must have been I guess.

some pics i took with the pistons removed. Looks almost like the sleeve burst. Pistons are good except the ring that ran over the crack a few times.

damn, thats unfortunate. sorry about your loss man. you decided yet who will be liable for the failure?

Doubt it's possible to prove anyone liable for this, so not going to go that route. The company that did the sleeves did complain from the get go that 92mm will leave very little material over, despite us all knowing it can be done. I'm giving up big bore motors. Been nearly 2 years since I really enjoyed my car due to continuous sleeve issues and wasted money. Building a straight up 88mm build now. Wont be the quickest but should be enjoyable enough.

why not keep a stock bore and go HCR, big cam combo?