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  • Engine: Reaming & deglazing or not?

    Hello guys,
    I am currently refurbishing an engine that shows only slight wear in the cylinder area. The piston rings are to be replaced, though. I thought I should use a slightly oversized set of rings but there is not enough clearance for that.
    So, I will revert to rings in standard size but I am now concerned by the slight ridge at the top of the cylinder. I know it is supposed to be removed but is this still mandatory with so little wear? The pistons went out of the cylinder quite easily and it seems to me that the ridge can’t harm the rings but I’d like to get more opinins about this. I must also confess that I read so horrendous stories about using a ridge reamer that I got cold feet about this one!
    I am also concerned by deglazing (or not) the cylinder walls as the instruction note I got with my set of rings don’t mention this at all.
    I’d be glad to get your feedbacks about all this.
    Nice day to all.

    sigpic

  • #2
    As insurance against a possible later problem, probably a very good idea to remove the ridge. If the ridge isn't that pronounced, and you've cold feet on using a ridge reamer, you could use a ridged (adjustable) bore hone. Really need to deglaze the cylinder wall with a very light honing. The slightly roughed surface will assist the rings to seat better and quicker.

    Bo
    Last edited by Bo Markham; 03-03-2020, 02:48 AM.
    Bo

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    • #3
      Christophe, their are 2 types of ridge reamer. the scraper type and the cutter type. the cutter type works best IMHO and will take out that slight ridge. it's harder to use but gives best results. then i would use a berry hone to de-glaze the cyls. a hone with rigid stones will straighten a cyl and make it nice and round but you are removing metal needlessly. just a swipe with a berry hone to de-glaze. if you dont remove that ridge you risk an annoying "Ticking Sound" and piston wear you can avoid. cut the ridge carefully and de-glaze and it shouldn't bother your conscience Luck Doofus PS i could never hear the ticking sound from motors others had built but a paying customer darn sure will!!!

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      • #4
        Originally posted by doofus View Post
        Christophe, their are 2 types of ridge reamer. the scraper type and the cutter type. the cutter type works best IMHO and will take out that slight ridge. it's harder to use but gives best results. then i would use a berry hone to de-glaze the cyls. a hone with rigid stones will straighten a cyl and make it nice and round but you are removing metal needlessly. just a swipe with a berry hone to de-glaze. if you dont remove that ridge you risk an annoying "Ticking Sound" and piston wear you can avoid. cut the ridge carefully and de-glaze and it shouldn't bother your conscience Luck Doofus PS i could never hear the ticking sound from motors others had built but a paying customer darn sure will!!!
        Really...I agree with the above. Peace of mind, and good practice when doing a minimum "refresh." All it takes is one ring to bump that ridge, crack (or worse), and the wreck is on. If you can snag a fingernail... hone or ream it out. I would rather risk an engine using a tiny bit more oil than taking a chance of cracking a ring, busting a piston, etc. You could count all my rebuilds on both hands with several fingers left over, but if I were to rebuild another, I would rather take the time to "retrain myself" on how to go about it, than bolt it back together just because the clearances are "close." If there's a ridge, take it out. Then...clean, clean, clean, pre-lube with reassembly lube, and bolt it back together, and enjoy.
        John Clary
        Greer, SC

        SDC member since 1975

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        • #5
          When installing new rings, if the bottom side of the shoulder at top of the ring travel area snags your fingernail, it must be removed to avoid cracking a top ring. Also, ALWAYS break the cylinder glaze when installing new rings (for chrome rings use a 240 hone; cast rings use 320, and moly rings use 400).

          THE PROBLEM: When removing the shoulder, no matter what kinda reamer/cutter, or how careful you are, you will never get a clean cut all the way around, because cylinder wear is neither perfectly cylindrical nor circular. The result will be a, "reverse shoulder" in spots cut too deep, or a remaining shoulder if you stop at first even surface. THE SOLUTION: per my favorite engine builder in the California desert, in the 1980s, instead of a bar hone use a ball hone. Of course keep it moving, but spend a little extra time at top of each cylinder. A bar hone will leave an untouched area below the groove, but a ball hone will not, and will round the bottom edge of the shoulder just enough so it will not break the top ring. This works great for motors not excessively worn (and probably oughta be bored and OS pistons fitted anyway). I have never used a bar hone since his lecture, and never had a cracked ring in those situations.

          CAUTION: before using the ball hone tape over all holes in the head gasket surface area of the block. If a ball comes off, it can wind up in the darnedest places, i.e. an oil passage. More advice from the old guy in the 1980s, who had been building motors for decades. .
          Last edited by JoeHall; 03-03-2020, 06:25 PM.

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          • #6
            If you decide to use a, "bore hone" mentioned in #2 above, be extremely careful, because the cylinder is softer than you'd think, and you can remove about .005" in just a few passes (don't ask how I know).

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            • #7
              I am currently refurbishing an engine that shows only slight wear in the cylinder area. . . . . . but I am now concerned by the slight ridge at the top of the cylinder.
              Good advice from all. Back in the bad old days, I've been there, done that and hope never again. Having been fortunate enough now to work in an engine shop with the right tooling and machinery is an education.

              There's an option to doing the best you can at home with hand tools. Take a night job as a greeter at Walmart and earn the $100 it will cost to have an auto machine shop with a diamond power stroke hone make the cylinders as straight as they can be. If you just clean up the top, you're leaving the cylinders funnel-shaped and forcing the rings to cycle in and out of the grooves with every stroke. This makes it impossible for the ring face to stay perpendicular to the cylinder wall. It's way better science for the cylinder to be .005" oversize for the full stroke than just at the top.

              jack vines
              PackardV8

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              • #8
                Thank you very much for all your sound and detailed advices. I have a much clearer view of all this now. Of course, it would be better to take the engine block to a machine shop, but the car is in a location that makes it difficult to take the engine out of it. I already had the valve seats grinded, BTW. I think I will take the ball hone route. Thanks Joe for mentioning the required grit. The info I found locally was 180 grit but this sounded a little too steep to me. Just for the record, the set of rings I have is especially designed to avoid to remove the top ridge. Thus, the top ring is stepped to avoid clashing with it. I mention this only because I don't know if such ring sets were available in the USA.
                Thanks again and nice day to all.
                sigpic

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                • #9
                  Never heard of those stepped rings, but the idea sounds good. Still, I'd round the shoulder a bit with the ball hone. Definitely don't use a 180 git for anything. The 240 grit is for chrome (top) rings to insure they seat, but cast iron rings will seat just fine with 320. The 400 is for the, "modern" moly rings, and is all they need. I have heard many folks complain their chrome rings never seated, yet most of them could not say what grit hone was used. A good machinist will sk you which rings you intend to use, so he knows which hone to use.

                  I am sure we all agree a rebuild (made new again) of the motor is best, but you'll get many more miles out of this motor with the approach you are taking. Hopefully you let us know how the, "surgery" went. LOL
                  Good Luck!

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                  • #10
                    I have had some engines where the ridge was pronounced enough that the pistons would not come out and the ridge had to be removed. If the pistons are forced past the ridge there is a high risk of breaking the top ring land. Also the carbon must be removed between each ring land with a carbon removing tool. I don't know how the top ring can strike the ridge, as it can only come up so far. The original piston ring assembly removed the material in the first place and stopped right at the ridge.
                    I would still remove the ridge anyway. On some engines the top ring comes right to the top and no ridge ever develops.

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                    • #11
                      Engine machining procedures, piston and ring technology have advanced greatly in the last 60 years what was done 60 years ago would not be acceptable today, however some of us are still doing things that way. In the day an engine would get maybe 80,000 miles and would need a rebuild, most engines would not see 100,000 miles. Today 100,000 miles on an engine is nothing and it is rare to rebuild a modern engine if ever. There use to be auto machine shops everywhere and now they are about 80 miles apart.

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                      • #12
                        Here is the car concerned by the rebuilt. A 1962 SIMCA 1000 that belonged to one of my grandfathers. These were exported to the USA but in small numbers. Except for those who were living in coastal areas at this time, I don't think many of you ever saw one in the flesh.
                        I put her back on the road a few years ago but noticed the lack of peps from the engine which had seen a little over 60000 miles. In fact, I was able to turn it by hand and the compressions strokes were barely noticeable! Of course, this is a tiny one by US standards with less than 58 CID (944 cm3 to be accurate)!
                        Upon examination, I found that the cylinder wear ranged from 0.0025" to 0.0028. As the first oversized pistons are 0.004", I did not choose the full rebuilt route. If all goes well, I should be able to get 20000 miles more before the first rebore. In all fairness, I have to say that I don't think I'll see this one as I put much less miles on my cars than Joe!
                        I just ordered the Flex-Hone and the corresponding honing oil from Amazon and will keep you posted about the progress.
                        You are very right about modern engines, David. Most recent cars go to the junkyard with an engine that was never opened. BTW, I don't think a garage would take the risk of a rebuilt nowadays, assuming he could find a really knowledgeable mechanic. What I am currently doing could not be applied to a modern engine and this is one the many reasons why I prefer to stick with the old ones.
                        Nice day to all.

                        sigpic

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                        • #13
                          As a bit of confession, when I first responded (post #4) I'll admit that I hadn't paid a lot of attention to you (Christophe)as the original author of this thread. At the time, I was having my morning coffee and distracted as I was catching up on the morning news. I quickly read the original post and comments that followed. For years, I have followed Christophe's postings and have the utmost respect for his opinions, sound mechanical suggestions, etc.

                          After realizing who the post came from, I'm confident the car and work undertaken will be in good hands. Also, my opinion of the original poster is elevated by the fact that even an experienced "tinkerer"/mechanic is wise enough to seek counsel and suggestions from others.
                          John Clary
                          Greer, SC

                          SDC member since 1975

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                          • #14
                            Looks like a fun project, and a fun little car to drive, when it's running again. I think the ball hone will work out well for you, and the "refresh" will get her up and running. Good Luck with it.

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                            • #15
                              Around here the Chrysler dealerships imported Simcas and there was lots of them in this area.

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