1G Cylinder damage

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Hi, this car has the original block, pistons and rods. It’s a 90. 4g63t. I put new rings in it probably 50k miles ago. Anyways, I only run around 22-23psi on a green and just recently started getting little random misses under boost. Did a leak down test and #3 was leaking out the exhaust.

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Pulled the head and had quite a bit of carbon built up on the pistons and head. 2 stem seals were leaking. I over looked the front side of the cylinder walls and started cleaning, lapping valves and replaced the stem seals. Started cleaning the piston tops and seen the Grand Canyon in number 2 cylinder. It’s never smoked or burned oil so I don’t know when this happened. Looks like it’s been there awhile I think. It’s a stock bore and want to get new pistons. I know it’s hard to judge just with a pic but would a bore over possibly get this out or may be get it sleeved if I can find a single sleeve?

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[donniekak]

Take it to a machine shop. They’ll run a hone in it until it cleans up, then measure it to see where you’re at piston size wise.

 

[bump]

Take it to a machine shop. They’ll run a hone in it until it cleans up, then measure it to see where you’re at piston size wise.

Ok thank you. That’s my plan but I’m just worried it it looks to deep to be honed out. But I guess that would be the only way to find out. Thanks again.

 

[donniekak]

Ok thank you. That’s my plan but I’m just worried it it looks to deep to be honed out. But I guess that would be the only way to find out. Thanks again.

Machine shops use pressure head power hones with diamond stones. They easily take cylinders to .020” or .040” oversize in minutes. Way faster than setting up a boring bar and then a hone.

 

[bump]

Machine shops use pressure head power hones with diamond stones. They easily take cylinders to .020” or .040” oversize in minutes. Way faster than setting up a boring bar and then a hone.

Called my local shop and they said it’s $25 a cylinder and if it’s over .040 they will machine in a sleeve for $105.