I had an engine rebuilt with 86mm Manley pistons. The block needed 1mm cleaning due to a broken tip of a spark plug in piston 1 before. Anyways, the engine ran well for 2k miles and the tune was spot on, Air fuel ratio was always around 11.8 at WOT. No knock whatsoever and i was also running 100% VP M1 methanol for extra cooling and safety.

Last 200 miles i started seeing white smoke when im on boost and let off. It got worse with time to the point where i started seeing oil spots on the rear bumper.

We teared the engine down again and this is what we have found




So what do you think caused the damage in hole 4? No knock and perfect air fuel ratio. Also top of the pistons are excellent shape.

Anyone wants to take a shot at it?

I found the reason for this issue, the engine builder didnt gap the rings and thought they were ready 🤦🏻. So the top ring basically scratched the hell out of the cylinder wall. Manely pistons provide a paper with the box stating what the three rings gaps should be at the different level of boost. Anyways lesson learned and it sucks that we have to sleeve the block.

Anyone have proper ring gaps for an evo running my setup?

I bought another set of pistons so far. Im waiting to see if they are capable of sleeving the block. I really didn’t discuss the cost with them just yet.

I was thinking to send the block to AMS and have them sleeve it for better quality and piece of mind.

thanks i will look into them