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Join Date: Jan 2018
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Ring filing
Is it possible to file an 82.5 cast goetze oil ring to fit an 80.5 bore. Or would it end up not round or would it conform to the smaller bore.
Ive run out of options to get an oil ring for my 67s that is .5mm over size. Or just fit std oil rings. For reference with new oil rings. .080" end gap with a new 80mm oil ring installed. The bores are well used and in spec albiet at the outer limit. Lyndon 
Last edited by Lyndon302; 10-15-2020 at 10:06 PM.. |
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10-15-2020, 09:40 PM
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Join Date: Aug 2012
Posts: 255
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Hi Lyndon,
Interesting question and probably difficult to be sure... I could run FEA-simulation on it however a bit of over the top ;-) Better is maybe to go a bit more experimental first. Take an old ring and file way more then needed to make yours fit the 80.5 bore. Then compress by hand and measure roundness and see if tendency is oval or still circular!? just a thought.... Cheers, Bart |
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10-15-2020, 11:59 PM
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Join Date: May 2003
Posts: 3,346
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I don’t think the gap is that important for an oil control ring. It’s just scraping oil from the cylinder and a 2mm gap would allow very little extra oil through.
__________________
72 Carrera RS replica, Spec 911 racer |
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10-18-2020, 08:22 AM
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Thats what I would like to think. It's not a race car. I have a good gap on the first and second.
Lyndon |
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10-18-2020, 12:20 PM
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Location: So. Ca.
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Use the Light Tight test cut the gap then install the ring in a loose barrel shine a flash light from the bottom and see if it is concentric to the bore. If not don't do it.
regards |
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10-18-2020, 03:34 PM
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Join Date: Feb 2005
Location: California
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I was able to buy 80.5mm rings directly from Porsche. It was a while ago, call Porsche and ask for 901 103 315 50.
andy |
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10-18-2020, 08:25 PM
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Ingenieur
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Yes, do this. It's all about conforming to the bore.
Quote:
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10-19-2020, 10:52 AM
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Join Date: Feb 2005
Location: California
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Intuitively, it seems like the rings would be made to a certain tension spec which you would be exceeding by using an oversize ring and filing back to fit.
andy |
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10-19-2020, 10:58 AM
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Quote:
No longer available. I have a 3 piece oil ring from a Honda B engine. 80.5 I'm looking to get the land depth taken in to accommodate these rings. Will report back |
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10-19-2020, 01:22 PM
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Engine is in. Top ring was good as it was new and specially made.
2ring is a Honda B engine. Perfect fit. 3rd is a standard new mahle 80mm. Runs great. No smell. No smoke and goes really hard. I'm happy Lyndon |
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11-05-2020, 10:05 PM
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