Rebore, hone or what?

How do you know what rings to buy when the shop needs the new rings first to measure how much to bore and the tolerance etc?

I believe the shop should be boring to piston size not ring size. It is piston to cylinder wall clearance that is the issue when determining if an overbore is required.

RomSpaceKnight wrote:

How do you know what rings to buy when the shop needs the new rings first to measure how much to bore and the tolerance etc?

I believe the shop should be boring to piston size not ring size. It is piston to cylinder wall clearance that is the issue when determining if an overbore is required.

Right. If your shop wants to size the bore to the rings instead of the pistons, take it to another shop.


I might add that piston to cylinder clearance is not the only reason to change out the pistons.

Pistons can have gauled pin bores. But, the most common over looked problem is worn ring groove size. As a piston starts to wear in the groove, the ring will move up and down. This is called ring flutter. As this happens, the wear in the groove accelerates. The wider the groove, the more flutter, which makes the groove even witer, etc.

I have seen pistons that were in good shape on the skirts, clearances OK, but the ring grooves ovewrsize.

Jay

I used a micrometer on my jugs and pistons marking them to make sure you put them back how theY WERE! 1234, they were all within factory specs put new set of rings and that was it ready to go! 5k miles and counting. Just make shure the specs are good check them at least 5 times!

ballstix, did you do anything to the cylinders, i.e. hone them before putting it back together? Just curious.

Thanks!

Willo46, If you did as ballstix did, and just re-ring, then you still need to hone the cylinder walls. They get oil glazed and the hone roughens the surface so the new rings can seat as they should. Honing is far less expensive than boring the cylinder.