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#Post#: 5711--------------------------------------------------
Hard To Find Or Custom Piston Rings
By: 660magnum Date: December 21, 2011, 12:49 pm
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Frank C Bowman of Farmington, NM has been making special and
custom piston rings for years. He has a great reputation in the
model airplane engine arena.
Some people remove the factory rings and install his rings.
You can even send your piston and cylinder to him and he will
custom fit a ring to the assembly.
Rings are $11-$12 ea plus $4 1st class or $5.65 priority
postage.
email: ringmaster46@msn.com Phone # (505) 327-0696
#Post#: 5712--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Chainsawrepair Date: December 21, 2011, 12:53 pm
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That sounds like a good deal. My last set of 181 thin rings were
$40 and 2100 thin rings were the same price a couple years ago.
Hey snoopy make sure you check this thread out.
#Post#: 5720--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Al Smith Date: December 21, 2011, 6:23 pm
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That's certainly reasonable enough .I have a set partly done for
a Mac 125 made of A2 steel .They just need finished with a
surface grinder .Before I got them completed I found a factory
set for 14 bucks though .
#Post#: 5725--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: 660magnum Date: December 21, 2011, 8:18 pm
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How does A2 work for rings? Were they hardened? Compare with the
original Meehanite gray iron for rings? Other variations?
From one extreme to another?
I had to repair a European engine that the guy had caught the
ring gap in the exhaust port at assembly. I was able to pull the
previously run ring out of the piston grove through the exhaust
port and it didn't break??? I figure he had originally got it
too hot? The hard cylinder wasn't scored.
The Chinese ideology of a ring is that it be very hard. Most of
the Chinese engines I see, you can run them for a year and the
ring is still not fully seated all the way across the exhaust
port. Of course they are running in a "as cast" cylinder.
#Post#: 5727--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Snoopy Date: December 21, 2011, 8:40 pm
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Thanks for the info. I need some 181 and 2100 rings ;D
#Post#: 5745--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Al Smith Date: December 22, 2011, 4:26 am
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I don't know how A2 would have worked because I never finished
them .I just figured it was more stable than 4140 and should get
hard all my itself kind of like gear steel . It was a pain in
the butt to cut without over heating it .Fact I got a few so
hard that carbide wouldn't cut them any more . I think I tried
to get 6 but only ended up with three good ones .
The reason I used steel instead of cast iron is because the
rings are so thin . I figured if I used iron that thin there
would be a good chance of breaking them when installing .
On that praticular instance it was a Mac 125 that I resleeved
with an iron liner .Grade 50 cast iron I think . Nodular would
have been tougher but it doesn't cut like gray iron .
FWIW if you search the net you can find a zillion places that
mention several methods of making rings .Interestingly many are
RC sites .Again though reiterating ,I've found more ideas from
RC sites than I ever have from chainsaw sites .
#Post#: 5750--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: 660magnum Date: December 22, 2011, 9:24 am
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I'm listening to you. I wanted to hear what you had to say.
I just never thought of making rings from it. But being air hard
etc, I could see where it might be a viable alternative.
I always thought D2 machined real crisp. You can spot it a mile
away because of the dull gray color. I suppose it would be just
too brittle?
Seems like L6 rough and then go ahead and harden then draw it
back would be hard but less chance of breaking? But I guess the
rough finish before HT and then a final finish grinding would
present a problem?
I noticed that a lot of things have changed in steels and cast
irons in the last 30 years.
#Post#: 5756--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Al Smith Date: December 22, 2011, 12:17 pm
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On some of the RC sites they speak about iron that once cut to
size is placed on a mandrel and heated to set it on a slight
expansion then cooled and tempered .You want some expansion but
not too much from what I gather .
Then you have to hand lap the rings while under tension using a
honing sleeve and fine lapping compound so it's pretty involved
.That's what I say if that gent can turn out good rings for that
price I wouldn't even fool around with them .
#Post#: 5757--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: Al Smith Date: December 22, 2011, 12:30 pm
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Let me toss another tid bit of info which I found out the hard
way .Don't use cutting oil in place of some type of coolant when
cutting hard steel .The danged oil shields the part and drives
the heat in .Tool steel will get so hard the only way to cut it
is with ceramic tooling which I have but most people don't .In
addition the harder it gets the less machinabilty it has .
If nothing else give it a shot of water from a mist bottle .I
myself can get water soluable coolant by the bucket full if I
need to for nothing .I just get a few ounces and mix it up as I
need it which isn't that often .
Now you could use something like "tap Magic " which cools by
evaporation but then you are breathing the fumes which I don't
think is especially healthy . On occasion I have used WD -40 but
I had a fan going at the time .
#Post#: 5761--------------------------------------------------
Re: Hard To Find Or Custom Piston Rings
By: 660magnum Date: December 22, 2011, 1:31 pm
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I'm still listening
I remember having a W&S 4B with a hydraulic leak and couldn't
get any production out of it at all with the hydraulic oil
getting on the work piece.
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