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  1.  
    Hello......It seems as if almost everyone has a favorite way to make their rings....I know that we had this discussion before,and I thought that it may be a good time to visit ring making again.....I know that we have a bunch of new members, and they would be interested to hear our thoughts and how we make the rings....I wondered
    if the members would would take the time to share their ways to make the "best" rings.....thanks....Dale Detrich
  2.  
    What spurred this on? Haha

    I recently used the Bob Shores method where you turn the inside/ outside diameters and part them off. I used a pair of diagonal pliers to crack the ring. Then i spread the gap about .020 inches and heated the area opposite the gap to a dull red color.

    There was some concern that a flat spot would be created in the heated area and the ring would leak. I checked 3 of the rings with a laser pointer and could detect no more of a gap than any other spot.

    I am not sure there will be adaquate wall pressure but I am not too far from trying to fire so i'll keep you posted.
  3.  
    Hello all,

    I think the best way to make rings is the George Trimbel way,his technique is in the early issues of Strictly IC mag. Its definitly not the quickest way to make good rings but the best in my oppinion. George was a NASA Engineer so he did his work thoroughly. I have all issued of S.IC and time and time again different builders refer and prefer his technique. There are countless other ways that I am sure get desent results as well. I guess you have to look at what type of engine you are building and its performance.
    By the way if you don't have all 84 issuies of Strictly IC get the while you still can.... they are a must have for all MICE.

    Have a nice weekend

    Jan
  4.  
    I've built engines using both methods, Bob Shores and SIC.

    Bob's method produces a slightly out of round form which is corrected by honing the rings installed in the piston into the cylinder bore, results are very satisfactory, compression is lower than SIC produce rings, however this may be builder error.

    SIC method produces more rounded shape rings, formulas for calculating rings are good, allowing for enough material to brake rings ( I prefer the cut them using slit saw 0.006 wide) the formulas provide for enough material to be remove from the ends of the rings anyway while fitting them into the cilynder.
    What I have found is that heat treating tends to form scales in the outside diameter of the rings, to prevent this, you can wrap them in Stainless steel foil ( MSC or Mcmaster sells it) and place a couple of kitchen matches inside the envelope to consume the oxigen. My preferred method is to use an old piece of exhaust pipe ( about 2 inches diameter), one end is capped and is about 3 inches long, I place the rings, with the mandrel, cap and a couple of kitchen matches inside, seal with a piece of metal and clay and then heat slowly until temperature is reached. This creates nice rings, heating seems to be more gentle and more uniform, producing no scaling in the rings.

    There was a publication in model engine builder (MEB) about using a similar Retort concept made of SS for rings.
    Now my two cents here, piston rings seal is not critical in the radial direction ( against the liners) it is more critical sealing against the piston groves, axially while moving up and down. So I place more emphasis in obtaining a polished surface in the ring sides after heat treating. polish them by hand in 600 grit sandpaper with some oil, measure with a micrometer to reach as close as possible thickness around.

    There has been a lot of research done in Cast Iron material to use, Ron's Chernich website (Ron's model engineering and model engines) have a very good discussion.

    Best regards.
    Jaime.
    • CommentAuthordavid
    • CommentTimeFeb 20th 2009
     
    I have always enjoyed making rings. But while Bob Shores was around it was a touchy subject.
    I have also successfully made rings with Bob’s method and the Trimbel method from SIC magazine. I get more round usable rings after heat treating with the Trimbel method. I use a steel or cast iron fixture to spread and clamp the raw ring for heat treating. I use a ant-scale compound that melts over the parts and keeps the oxygen out. The rings get dark but one stroke on 600 grit paper brightens it up again.
    I make 2 or 3 set and use a bright light to verify they seal radially against the cylinder and eliminate any that don’t. On my last vertical I reduced clearance between ring and grove axially as Jamie described and got better compression but just thought it was good rings.
    I have a drawing that summarizes the Trimbel method if anyone needs it.
  5.  
    Jaime,

    I wouldn't you say an all around good seal is the best seal.... ring to cylinder wall as well. I would certainly prefer this in my models.
    The Trimble way does not "break" the rings, a spesial cutter/clipper is to be made especially for this..... OK call it a controlled break. :)
    I have read another article in SIC written by a seasoned retro-model airplane engine restored and he had a much simpler approch to rings that he said were very satisfying. Like I mentioned earlier.... the engines performace should be taken to account, a slow show runner... the simple mothods will be good. If its high perfomace that is the goal... I would invest the extra time and effort and make the best possible sealing rings.


    Dale, I know you have bulit several engines that have many hours of hard running, I am not sure if my memory is right but don't you use a similar method to Bob Shores? ? ? Have you given the Trimble method a go ? ? ?
    Since you started this post.... tells us your method..... it certainly works well.

    Jan
  6.  
    Jan:

    Ring sealing against the Cast Iron liner will improve with use, the ring will hone into the liner and the seal will improve before it starts to wear off and degrade.

    Seal between ring and piston ring grooves will pretty much stay the same after many hours of running, with the exception of oil fouling and accumulation.

    Rings I've made using the SIC / Trimble method are running in a Sealion, clocking very good speeds (RPM's) and still have very good compression.

    Cheers.

    Jaime
  7.  
    I am relatively new to this hobby. I haven't made many piston rings, but I have made a couple different sets of rings a lot of different ways. The only way I was able to get consistantly good working rings was using the Trimbel method. These rings seem to produce good compression initially, and need little run in to produce great compression. I have also found that the Trimble ring geometry guidelines will keep ring breakage to a bare minimum, BUT I haven't made any oil control rings yet. When using my controlled heat treating (two propane torches), I have found that a generous coat of white silver solder flux works very well in preventing oxidation during heat treating. I am currently only building slow to medium speed throttled engines, and my oil control method uses a thin undercut under the lower ring with oil drain holes in the undercut. I am planning on using fewer rings per piston in future slow speed engines to reduce friction. This will move my lower ring above the piston pin. If anyone sees a problem with this oil control method above the piston pin, I would apreciate your thoughts or experience.

    Jeff
  8.  
    Jan....Hello....After a few years and attempts at making rings, I thought that I would bring up the ring making again to see what was working best for the builders.....I have tried to use the "Shores" way of making rings, But for me it seems as if I get a reverse bend just where I heated the rings.....I use a laser pointer and shine it at the point where the ring meets the cylinder wall, and look to see if any light is leaking past the ring/wall joint.....It is easy to see the light if it passes behind the ring...I just finished making 30 rings the other night ..I turn the O.D. to the cylinder dia. plus .002"/.003", so my .750 " rings were at .753" O.D......I turn the I.D. to the piston ring groove Dia. plus about .006", and that will leave about .003" to .004" room at the ring to piston fit.....I use a .010 cut off tool to part the rings off of the tube....I try to set the cut off tool, so that one side of the cut off groove is a good smooth cut.....So that gives you a smooth side, and a rough side to each ring as it is cut off of the tube....I cut the rings off and leave some spare stock, about .006"-.007" ......I make a tool to hold each cut off ring ( I will send some pictures to David) and ask him to post them so you can see the tool.....It is a fast , easy way to bring the rings down to the size that you want for thickness......The tool in the pictures is my tool for 1.000" ring, and.060" thick....You want to make the holder out of the hardest material that you have....You will have to turn the
    round down to fit the drill motor that you have (mine is turned down to .375")....You will have to bore a cavity to fit your rings, mine is 1.001 and is .060" deep....Try to leave a wide as posible outside rim on the ring tool....I next put a 1" X 30" belt (you want to use a worn out) , almost smooth sanding belt on the sander......Then fit a ring (with the rough side out ) into the holder.....Bump the holder into the belt sander, (with the sander off), then turn both the drill motor and the sander......This spins the ring, against the moving belt.....Sand the face of the ring until you feel the load come off of the belt sander.....Pull the tool away from the sander, and you should have a smooth side on the ring...Now reverse the ring in the tool, and again bump the tool into the sander belt.....Again
    start the sander and the drill motor, and when you sand the ring down to the right thickness you will feel the load come off of the sander again.....Just back off the belt, pop the ring out and check for the correct ring thickness.....
    Do not force the ring into the belt sander, use just enough force to keep the ring against the belt.....It takes a "bit" of time to get the feel of using the tool......Then I take the ring blank (it will have both sides sharp), and run it against a scotch bright wheel, to take away the sharp edges......I then use a toenail clipper to cut the ring then I use a diamond finger nail to clean up the cut ends of the ring....I now take the ring and fit it to the cylinder, and
    finish the ends of the ring to leave a small end gap....Now I find a bit of flat stock ( I used .080"), then spread the ring and "hang" the ring on the flatstock.....Then take a medium sizes propane torch, with a medium sized flame
    and with a circular motion bring the ring to a dull red color.....You will see the ring relax as it is being heated.....
    Then let the ring air cool down.....I think that is where I am having some trouble, and that is where the ring may twist durning the heating and cooling cycle....I think that I will see if I can come up with and make the holders to keep the rings from twisting while they are heating and cooling..........I get some "good" rings, and some not so good rings....Sorry to take up the space....If you have any questions, Please get in touch.....Dale Detrich
  9.  
    Dale,

    Thanks for telling us about your experiences.... you are a seasoned builder and its nice to hear.... its not that easy from guys like you.
    Have you considered the Trimble Method (as in S IC)? He used a heat treating holder ect. It may be the key to your distortion problem.....
    like we say here in Norway.... "You can't teach your father how to make children"..... in other words.... I am just a novice and I don't want to be sounding like an expert at all.
    You are the seasoned builder not me. :)

    Jaime,

    I agree but an all around good seal from the start has got to be better as the ring will wear more unifom.... wouldn't it ? ? ? ?
    Am I out with my microsope nitt-picking again.... sorry :)



    How about some others out there??? This is a very interresting subject


    Jan
    • CommentAuthorjay rich
    • CommentTimeFeb 24th 2009
     
    sorry guys i love my orings for the lack of heat friction and easy to fix or change i can say on ringed engines to aid in break in to help the rings use marvel mystery oil ive used thins on old briggs and orion engines to re seat new pistion adn ring sets in old blocks ....jay
    • CommentAuthordavid
    • CommentTimeFeb 25th 2009
     
    Dales notes, photos and drawings are in the Tips area.
    ->link<-
    Dale, thanks for sharing this with us.
    Remeber tips are always welcome.
  10.  
    Dale, great tip sheet thanks

    Jan
  11.  
    Dale:
    one of the ideas behind the SCI / Trimble device for heating the rings it to deform them to the expanded diameter, and to avoid twisting while heating and cooling, I use them finger tight and avoid heating the rings directly, concentration of heat in any single area. That is why I like the idea of enclosing them in a retort (kind off, it is an old piece of exhaust pipe from my old VW) and heat the pipe slowly, heating them to temperature and them maintaining the temperature for about 15 min, then let them air cool.

    I have made a small ring holder in the lathe to shave the sharp edge left by the cut off tool in one side of the ring. It is an expansion mandrel made of a 5C collet pot chuck.
    Cheers.
    Jaime
  12.  
    Apart from the issue of the method used to make piston rings; what materials have others found best/usable for the rings themselves? Convention seems to favor class 40 gray iron but has anyone used the ductile irons (65-45-12 or 80-55-06 for example)? Much of the cast iron I've located seems to be available only in 2.00" dia and larger dimensions. Any junk yard solutions for small diameter stock?

    Thanks to all for the info on making rings, I'll soon be headed into that task so the discussion was timely and useful.

    Garry
    • CommentAuthordavid
    • CommentTimeFeb 28th 2009
     
    I have always made my cylinder sleeve and rings from Cast iron.
    I have been thinking of making the sleeve from steel like 12L14. If I did that I would also make the rings from it. The Trimble method as I recall can be adjusted other materials by changing the gap.
    Has anyone made steel rings?
  13.  
    I've been considering trying rings made from a section of chrome moly 4130 steel tubing - not sure of the anneal/heat treat process though. It would certainly save a lot of boring / stock removal.
    Garry
    • CommentAuthorgbritnell
    • CommentTimeFeb 28th 2009
     
    The one thing I learned along time ago was not to run two objects together made of the same material, shaft-bushing, gear-gear, etc. They will gall up and wear very quickly. I have read that people have used 12L for cylinders. Personally I haven't tried it so I won't comment. Maybe someone who has will jump in. I would say that you can't make rings out of 12L or most mild steels for that matter. The reason is when you tried to open them to fit them on the piston they would bend rather than spring back. I don't think elasticity is the word I'm looking for but you get my point. I have always used cast iron for my rings and had good success. Cast iron has a natural self lubricating quality with the graphite in it so it works well for cylinders and rings.
    gbritnell
  14.  
    Rings material cast iron, have not tried others, liners, most water cooled use cast iron, several air cooled radial engines use steel liners 12l14 has good machining qualities.

    Steel liners seem to take more time to wear into the rings and achieve higher compression than cast Iron.

    Best regards.
    Jaime.
  15.  
    Thanks for all the great info. I'm pretty new to the hobby and all this will be really helpful on some future projects.Right now I'm working on a little brother for a friend.Take care , Mike Moslak
  16.  
    I have always annealed my Trimbel made rings at about 1000-1100F for about 10 minutes. I have found that the annealed rings usually will no longer fit the cylinder after annealing. This growth no doubt imparts some out of roundness to the final fitted ring requiring lengthy run-in. Has anyone found a lower annealing temperature, or procedure that does not cause ring growth?
    Jeff
  17.  
    Hello All........I have made cylinders out of both materials , cast iron, and 12L14 steel.....I have noticed that (as Jaime Q. has) that it seems to take longer for the rings to wear, and seat better with the 12L14 cylinders......On a second point or question ???? what type of oil do you use while first starting and "trying" to get the engine parts to "seat"..???? I can tell you what Not to use !!!! I have on hand a 5W40 synthetic oil that I use on my VW diesel , and when I used that oil , the parts did not want to wear......So is there any thoughts on what oil to use as a break-in oil ???? I would be interested in your thoughts, or history of break in oils.....Thanks......Dale
  18.  
    Hello, Well I believe that Lycoming aircraft engines still require mineral oil for the first 100 hours. You can buy it under the Aeroshell name. For our engines a quart would go a long way and at it's price, you want it to!!! Mineral oil does not have the additives that regular oil does. That's about all I know about the difference in the oils.
  19.  
    Dale,
    Lee Hodgson of Ageless Engines wrote an article in an issue of MEB on the preferred use of non detergent oils for break-in. This was determined from WWII, and current light aircraft enigne manufacturers recommendations. I don't know which issue the article was in, but his conclusion was that non detergent mineral oils will also provide the fastest seating of rings in model engines. Straight SAE 10 non detergent automotive oil is about the lightest (mineral) oil weight available, although it is not easy to find anymore. The diesel oils usually have more of the friction modifier additives that gasoline oils, hence will almost prevent run-in.
    Jeff
  20.  
    This is a bit late but its what the non expert will need.
    The only right way of making piston rings is by the Trimble/Chaddock/Wellshaw methods.
    For piston rings use only fine grain cast iron grade USA = G2, UK = GA300.
    DUCTILE IRON SHOULD NOT BE USED.
    Use the following formula and the above grade cast iron which is approx17 tons UTS and you will have the right spring tension against the cylinder wall.
    D = cylinder diameter.
    t =radial thickness,use D/25 to D/30.
    w = axial width,use D/25 to D/30.
    G = free gap,use t times 4.
    g = working gap,use 0.002 inches per inch of diameter.
    Do not cut the gap.break or snap the ring and only when finnished file the gap.
    Annealing/heat treatment,for forming the ring in the open position[free gap)using a wedge of t times 4,heat to 480-520 decrees centigrade,slow heat for 10 minutes,cool by air or quench in oil,if ring holds its t times 4 gap treatment is ok.
  21.  
    The rings should be made 0.002 inches oversize on outside diameter and after heat treatment using a holder that keeps them closed finnished to cylinder size.
    Another holder can be used to finnish them to piston ring groove size.
    Piston ring groove depth should be,piston ring + 0.004 inches.
    Another tool can be made to break/snap the rings.
    An assay on piston rings by T.D. WELLSHAW is recomanded reading,if its still there it can be seen on www.metalstop.com/technical/wall-ring/wal-ring1.html.
    • CommentAuthordavid
    • CommentTimeAug 23rd 2009
     
    Great site lots of interesting engine info. Go to ->link<- .
    Thanks for sharing it.