Piston Rings

[Gordon]

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?

 

[putputman]

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

 

[Gordon]

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.

 

[Piston_Broke]

http://www.deboltmachine.com/

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

 

[Philipintexas]

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...

 

[gus]

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.

 

[Philipintexas]

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

 

[stevehuckss396]

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.

 

[Swifty]

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.

 

[dsage]

Oops. Removed

 

[Philipintexas]

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..

 

[Swifty]

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

 

[gus]

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.

 

[Swifty]

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.

 

[dsage]

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

 

[Philipintexas]

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.

 

[gus]

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.

 

[gus]

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.

 

[gus]

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.

 

[Swifty]

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.