https://www.jalopyjournal.com/forum/attachments/ring-gap-jpg.5488671/ =========./ jpg.5488671/http://www.vanpeltsales.com/FH_web/FH_37-48engine-rebuilding/v8_overhaul-S123-1.htm http://www.vanpeltsales.com/FH_web/FH_37-48engine-rebuilding/v8_overhaul-S123-2.htm "Discard a piston if the clearance between the ring and piston exceeds .004" " . =========./ I'd discard any opinion that holds new ring side clearance much in excess of .004" is OK for re-use as-is. Yeah, factory wear limits don't define a part that will catastrophically fail upon engine start-up, or, if used in an engine will not deliver power, oil consumption, fuel economy or generally run Ok by 1950's civilian standards reliably for 20,000 miles 3 years. So maybe cheat a little. Not .010" plus. As others said, the worn ring is probably worn tapered and with a major step right at the corner of the old worn ring inside corner(s). No new ring will put up with that for long.
I was browsing around just enjoying exploring this site (this is a great website) as I just joined recently. Since this post is 8 months old you have by now probably solved your piston ring problem. My Dad was a automotive machinist. Owned an auto parts store and a machine shop started in 1947 in the Seattle area. When we sold the business he boxed up all the vintage parts and brought them home. Catalogs (yes catalogs) shop equipment and all. Now that he has p***ed it's still in the same boxes but in my home. I recall a box of ring groove spacers. If that's the route and you haven't taken it.
cool! do you have the catalog that shows the applications for them? That might make them useful to someone.
I think the standards for what is an acceptable repair have changed over the years. Back in the day the standard was to repair or patch just what was necessary. Nowadays we have adopted more of a whole hog or none mentality.
yup....and some of us are reverting to just getting it running, since the odds of it actually ever being driven many miles is so low.
From talking to people I got the idea that spacers were not the way to go. I also couldn't find the correct ones I needed so I bought new pistons. Finding parts for a Ford flathead six engine isn't very easy so I was trying to find the best way possible to get the engine running. BTW, I got the engine in the truck and have been working on breaking it in.
While this won't help you, esp now, something to consider for future searches; would be using metric #s & cross-referencing those for your particular application. Just may be helpful, since most stuff is now in that format, & has been for years. Mixing/matching/re-machining to use what's around might prove worth the time/$$$ - or not. Not that I'm happy about it, but it appears that I wasn't consulted about the change-over. ;D . Marcus...
I have probably cut several hundred pistons for top groove spacers over the years, along with knurling the skirt was a common repair to tighten up the top ring land clearance and piston to wall clearance years ago to get another 50000 or so miles out of an old engine. Perfect Circle and others made the spacers and I stocked a wide ***ortment of them. The tool used was manufactured by Perfect Circle, it is called a Manualathe. It pilots in the 2nd ring land and cuts the top land wider to accomodate the spacer. They came with an ***ortment of cutters for different width rings. I still have one of these Manualathe tools if anyone is interested in it.
I seem to recall the proper tool also cut a tiny groove into the back of the ring groove for the spacer The spacer ID was smaller than the groove floor diameter, so the spacer squeezed onto the piston and snapped into the tiny groove. Spacers go on the top side of the groove, towards the fire.
Knurled pistons. Man I haven't heard that since I was sweeping the shop floors on weekends when i was in junior high. Between your Manualathe, my groove spacers and this machine we can put the piston makers out of business. Lol.
I realize the original poster has replaced his pistons, but just for information I'd like to add a bit. Regarding the machining of the piston ring groove, the width is indeed very critical with the top and bottom needing to be parallel. However the depth will have much more tolerance as it is machined to have clearance with the back of the ring. After all, the bottom of that groove typically fills up with carbon. Since both the top and bottom of the groove would normally be cut in the same setup, they will be parallel, and have nice clean machined surfaces. If the groove ends up being a few thousandths unsquare to the bore, it wouldn't matter, so long as the surfaces are cleaned up. As a machinist, I don't see a problem cutting them to the recommended tolerance. But considering the cost of machine work, it would probably be cheaper to just buy new pistons.
Hello Sir, Yes, my Dad saved not only the parts but the complete catalog racks from the store. This is one of 4 racks. I know this technology is before my time so I have no business commenting or should I on if it is even relative today. I do know that there is a wealth of information in catalogs you cannot find elsewhere. So if there are members out there that I might be able to look something up within reason (Part #, Dim, Spec.) I would be happy to give it a shot.
Plus worn valve stems, valve guides, .010" taper in the cylinders and needs a crank turn. I built my first 223" more than fifty years ago. I'm old enough to have used a chain hoist from the rafters and re-ringed it working on a dirt floor. That was then. Today, it all depends upon whether one is doing his own labor or paying a shop to do everything. In shops, we know it takes the same hours to R&R, dis***emble, clean, check and re***emble junk parts as it does to work with new parts. Beyond that, it takes many more hours to knurl pistons and valve guides, machine ring grooves for spacers, regrind used valves and lifters, instead of just installing new parts. Bottom line - I don't know any shop today which will touch a patch job. They've learned it will take longer and cost more and will be more likely to run into problems where the used parts aren't salvagable. Your build, your money, your decision. jack vines Tip - if one could be found, the 262" version in '61-'64 medium- and heavy-duty trucks had lots of heavy-duty stuff in them. BTW - if anyone needs a rebuilt oil pump for a 223", I just found one under the workbench; PM me.
That's true, thanks for explaining some of the reasoning. More reasons are that they have to stand by their work, and their reputation is on the line. But for those of us who can do the needed work at home to overhaul an engine well enough to make it last 10k miles or so, for a couple hundred bucks, it's a whole different story. That's how I did things almost 50 years ago, it worked then, it still works.
I think I've only worked on ***embling one engine that had groove inserts in the pistons. It's been too many years ago to say for certain, but I thought the inserts were on the bottom of the grooves. I'm probably mis-remembering, but either right or wrong, why would it be preferable to have the spacer at the top of the groove? Is it a matter of better controlling heat at the top of the piston, as you stated about installing them "facing the fire"? Or did the rings somehow seal better with the spacer on the top?
I vaguely recall that groove cutting tool (in addition to the groove cleaning tool) in the Sears and Montgomery Ward tool catalog in the mid fifties. Sealed Power and TRW had spacers listed at one time. The op did the right thing by ordering new pistons, though. There were a lot of “make do to get it through another harvest season “ repairs done back when new parts were expensive and labor was cheap. Reproving worn pistons and adding a spacer was certainly cheaper than pulling the engine, reboring, and re***embling with expensive new pistons back then.
This place will get you whatever you need Ring related. https://www.totalseal.com/ Off the shelf stuff, you Want exotic, or custom weird stuff, a one off set, have odd ball bore, need special thickness, coatings, special alloy,
Maybe my 1st sentence??? = "While this won't help you, esp now, something to consider for future searches". I suppose I should've stated "& anyone else too", but thought that abit redundant. Was/am well aware of the post-dates, again, the 1st sentence. The small sized piston needed just might show up in "late-model" 4cyl, so-called domestic or even so-called foreign. While it couldn't matter to you or anyone else, IIRC, at least one of the Stude straight-8's can use pistons from a OT 80's dodge 4cyl(I hesitate to call them "bangers"), if a little thought & machining "trickery" is applied. Rings, pistons, lifters, rockers, bearings, et-al can be subs***uted, if dimensionally close & compensated for w/good machining. Sometimes there is no choice 'twixt this, custom-made, or walking away. Depends what you want... Marcus...
You must remember that 40 years ago this was not considered a "patch job". It was the standard overhaul machining procedures promoted by the major manufacturers of engine rebuilding components and it worked well. Most all of the Indy and many other endurance engines of the 50's and 60's had knurled pistons for oil retention on the piston skirts.
Often a ring groove cleaner was made from one of the old rings that was snapped and broken (intentionally) to produce a sharp edge. The broken edge was then used to s****e carbon and varnish out of the ring groove. It was just the right width to get into the deeper recesses of the ring groove, and it wasn't intended to remove any material from the piston. And it wouldn't gouge or score the ring sealing surfaces like a knife or a screwdriver blade might, especially on an aluminum piston. On some racing applications it was fairly common to use groove inserts to allow the use of a narrower, low tension ring set on pistons that originally used wider stock rings.
I’ve used a ring before as well. Then a week later I stumble across the groove cleaner tool. The one I have does either 3 or 4 land thickness sizes. I should go find it and hang it on a wall in plain sight
Might help to paint it day-glow orange too! I'd forgotten about those groove s****er tools. The "business end" of them had an adjustable rotating head with like 3 or 4 different width bits or s****ing tools. I think somebody like Lisle or K-D tools used to make them, a**** others.
I can't imagine all this effort to save $300. It's just not the way to rebuild anything. 70 years of engine work has taught me the shortcuts eventually failed and should have done it right the first time.
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