The Stovebolt Site Forums The Shop Area Engine Shop Ring Questions 1950 3600 216

I'm getting ready to put the new pistons in my 216 and started by checking the rings in the bore. According to the shop manual, the end gap should be .005 to .015 but I'm finding them to be in the .017 - .018 range. The paper that came with the rings says the end gap should be .003 - .004 per inch of cylinder diameter. The 216 has a 3-1/2" bore standard (mine's .030 over) so, according to the sheet, the gap should be about .010 - .014.

Also, I was checking the ring clearances in the grooves. For the compression rings, the manual says a .0015 feeler gauge should fit freely and a .003 feeler gauge should have a "rather heavy drag." I have the heavy drag with the .0015 feeler gauge in both grooves.

I know the manual was written 60 years ago when they were using cast iron pistons. I'm replacing them with aluminum pistons so I'm not sure if some of the measurements have changed with the updated technology.

Has anyone come accross this issue and how did you deal with it?

Thanks,
Shawn

Are your rings good for your .030" cylinders? I don't know about the ring land clearance but your gaps sound pretty close to me.

They're supposed to be .030 oversize rings. The box has 030 at the end of the part number so I'm thinking they should be the right ones. Of course it's always possible a package can be mislabled. Thanks Truckernix.

.012 would be the minimum spec or as little a gap as you could/should have. The .0015 grove would again be a miminum spec. You are good in my opinion.

.012 would be the minimum spec or as little a gap as you could/should have. The .0015 grove would again be a miminum spec. You are good in my opinion.

Did you bore it .030 or was it already bored and you are re-ringing it? If it was already bored before, I would not use anything but cast iron rings. Did you measure the gap at various points. You could get different gaps if you have taper. But here again it depends on if you have a fresh bore. Since aluminum expands more than cast iron, I think you should have a little more clearance in the groves to keep the rings from sticking when the engine is hot.

Sorry guys. Lots going on the rest of the weekend so I haven't been close to a computer for a while. The engine's freshly bored. Thanks, Shawn