# Piston Rings



## Gordon (Feb 19, 2015)

In the past there was a company which sold piston rings for small engines. I believe that the company is no longer around. Is there another company where it is possible to purchase piston rings?


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## putputman (Feb 19, 2015)

I have always used Dave Reed at Otto Gas Engines. (410) 398-7340
He is reasonably priced and good quality.


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## Gordon (Feb 19, 2015)

That is who I was trying to remember but it appears that they are not longer in business. None of the links seem to work.


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## Piston_Broke (Feb 19, 2015)

http://www.deboltmachine.com/ 

I see these guys at NAMES every year. High quality stuff at a good price.


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## Philipintexas (Feb 21, 2015)

Piston rings are fairly simple to make and fine-grain cast iron stock is readily available. I've made rings for all my engines. Hate to admit it but I have to because I can't hold tight enough tolerances to use stock sizes...


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## gus (Feb 21, 2015)

Hi Gordon,
Used to buy from them but they won't ship overseas. Had to bother my good friend to post to me. Been making my very own DIY C.I.Piston Rings for my last two engines with good results. 
The Howell V-2 will also run with DIY Rings too.
Making your own DIY Rings is not very difficult and not a black art. I can count a dozen of HMEM Members cut their own rings and cutting DIY Timing Gears too. Please post piston ring drawings and we will help. The heat treatment is no big deal and easliy done with a Propane Gas Torch. The Nemett-Lynx Engine ran with DIY Rings. The Howell V-2 require  3 rings.


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## Philipintexas (Feb 22, 2015)

GUS:  To what heat treatment are you referring? I've made many and never heat treated them?? Always ready to learn.


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## stevehuckss396 (Feb 22, 2015)

Philipintexas said:


> GUS:  To what heat treatment are you referring? I've made many and never heat treated them?? Always ready to learn.




One way of making rings is to bore, turn, and part off to size. Then the ring is cracked apart and put on a fixture to hold them open. Then they are heated to stress relieve them. When taken out of the fixture they stay open and need to be forced closed.


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## Swifty (Feb 22, 2015)

stevehuckss396 said:


> One way of making rings is to bore, turn, and part off to size. Then the ring is cracked apart and put on a fixture to hold them open. Then they are heated to stress relieve them. When taken out of the fixture they stay open and need to be forced closed.



And therefor holding them tight against the bore.

Paul.


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## dsage (Feb 22, 2015)

Oops. Removed


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## Philipintexas (Feb 22, 2015)

I see.... I measure the bore, compute the circumference, add about .040 for the gap-size, convert that back to diameter and make them so that after parting off, I can saw the gap and then file the gap until I have a tight fit in the cylinder with only a couple thou. gap. Never thought of doing it your way..


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## Swifty (Feb 22, 2015)

Philip, check here http://www.homemodelenginemachinist.com/showthread.php?t=23065&page=9, starting at post 88. You will see how I made my piston rings. You have to turn them to the bore size, then crack them and heat treat them. This is a very simple method and worked well for me and other members, no complicated working out of circumferences needed. Once the rings are in the bore, they form a near perfect seal in the cylinder.

Paul


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## gus (Feb 23, 2015)

Philipintexas said:


> GUS:  To what heat treatment are you referring? I've made many and never heat treated them?? Always ready to learn.




A clamping jig is required to hold the stack of 3---4 rings tight. Heat to cherry red and hold for min. of 5 mins and quench in water. View Paul's thread.

Paul Swifty, Please audit.


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## Swifty (Feb 23, 2015)

gus said:


> A clamping jig is required to hold the stack of 3---4 rings tight. Heat to cherry red and hold for min. of 5 mins and quench in water. View Paul's thread.
> 
> Paul Swifty, Please audit.




Gus, I just let mine cool naturally, as slow as possible would probably give the best results, we don't want to introduce any stress to the rings.

Paul.


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## dsage (Feb 23, 2015)

Yes. For sure you DO NOT want to quench them. I'm surprised they haven't cracked. Hopefully they won't do so in the engine. You are actually trying to relieve the stress put into them by stretching the gap open so the gap remains set in the new position.

Sage


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## Philipintexas (Feb 23, 2015)

SWIFTY: Very interesting method, Next time I make rings I'll try your method. Since you guys in Aus. are upside down I guess you see things differently.  ;D

Does anyone worry about the lack of a gap for heat expansion? I try to leave a few Thou.


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## gus (Feb 23, 2015)

Philipintexas said:


> GUS:  To what heat treatment are you referring? I've made many and never heat treated them?? Always ready to learn.



I used Malcom Stride's method to make and heat treat piston rings. See attached.

Malcom's book is highly recommended for DIY Engine Builders.


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## gus (Feb 23, 2015)

Swifty said:


> Gus, I just let mine cool naturally, as slow as possible would probably give the best results, we don't want to introduce any stress to the rings.
> 
> Paul.



Hi Paul,

Gus has bad memory. Piston rings and jig was left to air cool naturally.


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## gus (Feb 23, 2015)

dsage said:


> Yes. For sure you DO NOT want to quench them. I'm surprised they haven't cracked. Hopefully they won't do so in the engine. You are actually trying to relieve the stress put into them by stretching the gap open so the gap remains set in the new position.
> 
> Sage



Hi Sage,

You are correct. Piston rings and clamp jig were left to natural cool down overnight. Been six months since making the rings.

Piston rings would have distort or crack if quenched. Just referred to Malcom's method which I followed on heat treatment and cooling.


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## Swifty (Feb 24, 2015)

Philipintexas said:


> SWIFTY: Very interesting method, Next time I make rings I'll try your method. Since you guys in Aus. are upside down I guess you see things differently.  ;D
> 
> Does anyone worry about the lack of a gap for heat expansion? I try to leave a few Thou.



I filed the gap to .004" when fitted, I have had no trouble with expansion of the rings. The method isn't mine, it was written up in Malcolm Strides book about the Lynx.

Paul.


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## Charles Lamont (Feb 24, 2015)

gus said:


> A clamping jig is required to hold the stack of 3---4 rings tight. Heat to cherry red and hold for min. of 5 mins and quench in water. View Paul's thread.
> 
> Paul Swifty, Please audit.



And, as I understand it, cherry red is far too hot.


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## Swifty (Feb 24, 2015)

Charles, Malcolm Stride advocates holding the rings at red heat for 10 minutes, I must admit that I got tired of waiting after 5 minutes and left it to cool down after that. Of course, we are only taking the stress out of the rings, and perhaps some leeway could be taken with the amount of heat applied. My rings certainly stayed sprung open as required.

Paul.


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## Cogsy (Feb 24, 2015)

The procedure I have used several times is the Upshur method and advocates dull red for 60 seconds then a slow cool. Mine too have always retained their sprung gap and sealed well. 

I personally think that although there are many methods and undoubtedly a best practice, in reality cast iron rings at the size we use, and for the use we demand out of them, are not overly critical in their manufacture and heat treating procedures.


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## Charles Lamont (Feb 24, 2015)

Swifty said:


> Charles, Malcolm Stride advocates holding the rings at red heat for 10 minutes



I know he does, but others disagree, with reasons:

http://www.jerry-howell.com/PistonRings.html


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## dsage (Feb 24, 2015)

I've always tried to make them by the Trimble method but I leave out the final skim of 1 thou off the diameter. I found more eccentricity in the mandrel and the clamping than 1 thou so it was futile to try. My engines have never smoked even on first pull. The link to Jerry Howells site mentioned earlier http://www.jerry-howell.com/PistonRings.html is about the best summarization of the many documents written on the subject that I've found. And I've tried to collect all of the originals.
You can't go wrong if you read, understand and follow the instructions presented there.

Sage

http://davesage.ca


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## mu38&Bg# (Feb 24, 2015)

Every time I read about making rings, the author mentions "heat treat". Heat treat describes any heat processing, but many associate it with quenching to harden steel. In ring making you are trying to stress relieve the rings to take the new open shape so as to provide pressure on the cylinder wall. Why is the term stress relieving rarely used?

Annealing of gray irons requires heating to 1290°-1400°F, 700°-760°C (cherry red) with slow cooling. Stress relieving needs only 1020°-1200°F, 550°-650°C (blood red -dark cherry). You stress the ring by stretching it open and when those stresses are relieved the ring retains that shape. The temperature difference is small. Above annealing temperatures, other things begin to happen changing the properties. Oil quenching does surface harden grey iron, but on a thin section such as rings you might expect other issues.

This is of value if you want to learn more. www.dtic.mil/cgi-bin/GetTRDoc?AD=AD0620556

Greg


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## Swifty (Feb 24, 2015)

Charles Lamont said:


> I know he does, but others disagree, with reasons:
> 
> http://www.jerry-howell.com/PistonRings.html



Next time I have to make some rings, I will certainly try using a lower temperature. The avoidance of scale is important.

Paul.


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## gus (Feb 26, 2015)

Swifty said:


> Next time I have to make some rings, I will certainly try using a lower temperature. The avoidance of scale is important.
> 
> Paul.



Hi Paul,

Good idea. Keep Gus posted. Had a great day with the Outerheads. Was productive but a wee bitty hot and humid.Makes me tired.


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## Philipintexas (Feb 26, 2015)

I guess ignorance is bliss, I've never done anything to rings in the way of heating/stress relief and they have worked just fine. Sometimes the KISS method works.


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## stevehuckss396 (Feb 26, 2015)

Philipintexas said:


> I guess ignorance is bliss, I've never done anything to rings in the way of heating/stress relief and they have worked just fine. Sometimes the KISS method works.




Not surprised! Bob Shutt has been running his Peewee V4 for about 5 years now without rings. I suspect they are not as important as we think they are at this scale.


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