cylinder scoring/scratching

[DieselTech]

any tips to keep them in place while I put the cylinder on

Are the piston rings rotating on the piston? Or should I say will the piston rings rotate on the piston?

 

[Toby woodman]

the rings will rotate when the piston is not in the cylinder but I think that is normal?

 

[Toby woodman]

when I opened the cylinder after it seized there was nothing wrong with the engine inside just a large score on the piston. could the fact that the cylinder seems to not line up with the block at the bottom. it seems as if the studs are not in the right place. could that cause the scoring.

 

[ImpulseRocket]

Those pictures don't show us anything important or related to the problem. The inside of the engine is what matters.

 

[Chainlube]

when I opened the cylinder after it seized there was nothing wrong with the engine inside just a large score on the piston. could the fact that the cylinder seems to not line up with the block at the bottom. it seems as if the studs are not in the right place. could that cause the scoring.

Was that engine completely assembled when you got it? Did you pull it apart for assembly inspection before you run it?

My point is, some over cast in the intake port could have broken off with the first heat cycle and got trapped between the piston and cylinder wall causing that scratch. You can confirm this if there is a piece of the intake port that is broken off and chipped the bottom of the port.

 

[Toby woodman]

Was that engine completely assembled when you got it? Did you pull it apart for assembly inspection before you run it?

My point is, some over cast in the intake port could have broken off with the first heat cycle and got trapped between the piston and cylinder wall causing that scratch. You can confirm this if there is a piece of the intake port that is broken off and chipped the bottom of the port.

I didn’t take it apart before I ran it but the ports look okay. There were some small bites on the cylinder wall that I filed down though. I was probably running the clip on the needle a bit lean as well which wouldn’t have helped

 

[Chainlube]

I didn’t take it apart before I ran it but the ports look okay. There were some small bites on the cylinder wall that I filed down though. I was probably running the clip on the needle a bit lean as well which wouldn’t have helped

I seen too many poorly casted cylinders to trust any straight out of the box. If you ran it hard without much break-in time that will make the matters worse. Unless you run it lean and hard for a sustained amount of time, I don't think the needle position had anything to do with it. I don't think that top end is going to last very long now, of course you could really baby it and keep the speed down and get a month out of it.

 

[Wrench]

Casting slag