How do I know what rings to buy

[Deleted User]

I have a 1950 Hudson Pacemaker with a 232 cu inch engine. I measured the top of the pistons and they seem to be exactly 3.5 inches in diameter. They are pinned rings. When I pulled a piston, I tried to remove a ring and broke one. I did not like the looks of the pinned rings because it looked like I should lose compression because all the top rings had the gap in the same place. It did not look like the gap closed all the way when the rings closed. Can I buy replacement rings that are not pinned, if so how do you remove the pin and cover the hole. What is best? How do I know what size rings to order? I don't suppose they sell rings for just one piston do they :-(.

EssexAdv

contact: Paul Weaver Paul Weavers Garage 680 Sylvan Way Bremerton WA 98310-2844 (360) 373-7870 They sell open stock rings. HE will sell you one it that is all you need.



To remover the pin, you can either drill it out from top to bottom or use a dermel tool and cut the pin out of the ring groves. Have the hole in the piston welded up if you have drilled the hole

Uncle Josh

On the other hand, aside from 4 fingers and a thumb,



The pinned rings are all machined a little differently where they go on the same pin, so they will block each other slightly. Smart, eh?



Then, when you go to put that piston back in there, you'll notice the lower oil ring pin is about 1/3 of the circumference off from the top pin.



It's easier to get the bottom ring in first using a hose clamp for a ring compressor, so you can see what you're doing, then use the regular compressor on the top rings.



If the rings arent free in the grooves, you'll have to take them all out and clean the grooves. If they're really stuck, you'll have to break most of them.



To replace them, or to remove free ones, use a ring spreader, available at Sears for about $6 and many other places.

Uncle Josh

By the way, the bore is 3 9/16 or 3.5625. 232 uses the same rings as the 262.

dave s

Dale Cooper has both pinned and non pinned rings. Dale Cooper has bought out Bob Rovengo's inventory of engine gaskets, seals and engine rebuild parts for a lot of engines 1914 to 1957. All gaskets are either new or N.O.S., all cork and paper gaskets are new manufacture. He has bearings, valves guides and springs, timing components, pistons and rings (some original pinned piston rings) , lifters, oil pumps & kits, thrust washers and crank spacers for vibration damper 1931-56 6 and 1934-52 8. Catalog is viewable online at http://www.hudsonmotorcarco.com

Park_W

Based on recent experience, I strongly advise against trying to cut the pins out with a Dremel or other tool. When you do that, it's almost impossible to avoid scuffing up the lower surface of the ring groove, and the ring MUST be able to seal well against this bottom surface, which it won't if it's scarred up. I've just had to pull an engine down and replace the pistons with ones that weren't damaged this way. They caused bad compression leakage and burning of the pistons where the leakage was taking place. And Uncle Josh is right ... the notch in the rings is offset, and you put one in "upside down" compared with the other, so the gaps are offset from each other.

[Deleted User]

I ordered a shop manual, will it tell me how the rings go back. It sounds like I need to take. I did not know one went upside down relative to the other. In addition, it does not look like my rings go all the way around the piston when fully compressed. It looks like a space will be left for compression loss.

[Deleted User]

There is actually no gap on the rings of a properly installed piston and no compression loss when you look at the bore and stroke of a Hudson 6 you can calculate the resulting compression and this should be at minimum a 100 Ibs.



The way a pinned ring does not display a gap is that the rings are notched on the inner diameter at the gap slot. And here is a Hudson engineering quote:



" Width of the notch is .125" total of which approximately .075" is at one end of the ring and .050" at the other end. This offsetting of the notch enables a single pin to anchor the 3 top piston rings without having the gaps aligned on adjacent rings"



If you are see a gap your rings are worn or maybe the grooves need cleaning if you have the pistons out I would do a good cleaning and use a groove cleaner and yes the manual will show you how to install them and what to look for.