piston ring check with head off

[Gregor]

Hausdok,
I will try and get a photo here over the next day or so. If you are facing the car from the front of the engine, the "scuff" mark is on the right (drivers) side of the cylinder wall and about 1 1/4" or so down from the top edge of the cylinder.

[njonkman]

Hausdok,
I will try and get a photo here over the next day or so. If you are facing the car from the front of the engine, the "scuff" mark is on the right (drivers) side of the cylinder wall and about 1 1/4" or so down from the top edge of the cylinder.

Then it can't be the wrist pin, it would be front or back. Probably a broken ring.
Nick

[hausdok]

Hausdok,
I will try and get a photo here over the next day or so. If you are facing the car from the front of the engine, the "scuff" mark is on the right (drivers) side of the cylinder wall and about 1 1/4" or so down from the top edge of the cylinder.

Hi,

When the piston is at TDC, that is just about where the piston skirt meets the bottom of the oil ring groove. Those rings are supposed to scrape the oil off the cylinder wall as they recede toward BDC. If you've got a clearly defined scuff like that I'd suspect a broken oil ring or ring land. Instead of recompressing smoothly like it's supposed to, something is causing that oil ring to hang up and exert excess pressure against that cylinder wall and it's wearing a groove in the wall.

You've got the head off, it's not that much more work to pull the pan. Pull the pan, pop that piston out and check it out. I'm betting you're going to find a broken ring or cracked skirt and that, once you have that cylinder mic'd, you're going to have to pull that engine and have it bored to restore that cylinder wall. That means you'll need to install oversized pistons and rings to restore that cylinder wall. If it's not too badly worn that is. If it's too far gone, perhaps it'll be possible to sleeve the cylinder. If not, it'll be time to start looking for a new block.

Edited shortly thereafter: On second thought, before you start pulling that pan, check with your local auto parts stores to see if any have a tool lending/rental program. What I don't have, I can usually borrow from the O'Reilly's down the street and if I bring it back that same day there is no charge. Pick up an inside micrometer. Rotate that cylinder to BDC and mic that cylinder. Then check your manual to see how far over spec it is and whether it's fixable with simple boring or you'll need to start resourcing a block or someone who can sleeve it.

[Gregor]

Thanks Hausdok, now you're talking. I appreciate your input.

[DEEPNHOCK]

Hi,

When the piston is at TDC, that is just about where the piston skirt meets the bottom of the oil ring groove. Those rings are supposed to scrape the oil off the cylinder wall as they recede toward BDC. If you've got a clearly defined scuff like that I'd suspect a broken oil ring or ring land. Instead of recompressing smoothly like it's supposed to, something is causing that oil ring to hang up and exert excess pressure against that cylinder wall and it's wearing a groove in the wall.

You've got the head off, it's not that much more work to pull the pan. Pull the pan, pop that piston out and check it out. I'm betting you're going to find a broken ring or cracked skirt and that, once you have that cylinder mic'd, you're going to have to pull that engine and have it bored to restore that cylinder wall. That means you'll need to install oversized pistons and rings to restore that cylinder wall. If it's not too badly worn that is. If it's too far gone, perhaps it'll be possible to sleeve the cylinder. If not, it'll be time to start looking for a new block.

Edited shortly thereafter: On second thought, before you start pulling that pan, check with your local auto parts stores to see if any have a tool lending/rental program. What I don't have, I can usually borrow from the O'Reilly's down the street and if I bring it back that same day there is no charge. Pick up an inside micrometer. Rotate that cylinder to BDC and mic that cylinder. Then check your manual to see how far over spec it is and whether it's fixable with simple boring or you'll need to start resourcing a block or someone who can sleeve it.

Sort of like post #2, huh?

[Gregor]

Not "sort of", exactly!

I appreciate all your inputs and decided instead of screwing around with this mickeymouse "maybe I can fix it cheaply", I am pulling the engine and see if it can be sleeved, etc.
I need to find a trusting/good machine shop here in Jacksonville, FL next.

Thanks again to all!

[Gregor]

I have pulled the engine and had the head gone over totally, and am planning to replace all the rings. I haven't removed them yet, I am trying to find a supplier for rings.
Kanter advertised that they have them but they don't, and Studebaker Intl doesn't carry 1961 stude lark ohv 6 rings. DOES ANYONE HAVE A GOOD SOURCE FOR THESE RINGS THAT THEY WOULD LIKE TO SHARE WITH ME? Thanks in advance.

[Alejo]

Hey Gregor, I'll have my 1955 Champion in Gainesville early next month so I can work on the engine. Maybe when both are done we can meet up!