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Preferred pronoun:Maestro
Join Date: Sep 2012
Location: Group W Bench
Posts: 11,359
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Goetz Piston Ring Install - Orientation
I thought I'd read somewhere that there's a difference between the top and second compression rings but I can't seem to find the thread now.
In his eagerness to help get my 1980 930's engine together, my 13 year old son carefully removed the rings from their packaging and laid them out next to each piston/cylinder combo. I'm not convinced though that he kept the compression rings in the order they were packaged/labeled. To be fair, I'm also not certain whether there's a difference. They appear to measure the same (my crappy digital caliper can only be trusted so far) and all markings appear identical. Both are beveled, apparently at the same angle. Hoping someone can shed some light on whether or not the top and second rings are indeed the same and if not, how to identify the difference. Thanks.
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08-08-2014, 04:41 AM
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Look really, really closely, they should have a different bevel on the inside of the ring.
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08-08-2014, 04:52 AM
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Location: So. Ca.
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If there are no marks the gap on the inside ring goes up on the compression ring and down whether it be on the inside or outside of the 2nd.
regards |
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08-08-2014, 06:33 AM
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Straight shooter
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The top two rings should be marked with lettering which should always face up to the top of the piston. The top ring is usually chrome plated and the middle or second compression ring is not.
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08-08-2014, 08:13 AM
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Preferred pronoun:Maestro
Join Date: Sep 2012
Location: Group W Bench
Posts: 11,359
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Getting a pretty good look through a reasonably powerful magnifying glass and can't see any differences.
Markings are the same. Bevels and lands look the same. Finish (appearance) is the same. Seem to be the same dimensionally. I'm concerned because the consensus sure seems to be that there are differences between the top and second ring and I don't want to assemble this thing only to discover is has to come back apart.
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08-08-2014, 11:47 AM
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If you can't see any number or letter on the side of the compression rings near the gap I would ask Henry tomorrow. He's a really nice guy and from my experience he'll come to the phone and help if you call his shop. The number is in his posts.
I have this diagram from the factory manual showing where the ring gaps should be positioned during assembly. I hope it helps. 
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08-08-2014, 06:16 PM
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Did you keep any of the little yellow envelopes the rings came in? There might be a reference pic in there. I'm pretty sure the stock 3.3L Turbo rings are different for the first and second land but maybe not. Do your rings say "goezte" on them in little gold letters or do they have the word "top" etched into them.
If they have either, are both rings marked with the same word? Too many back and forths this year doing M96 and air cooled motors. I'm looking in my files for a pic, but no luck so far. |
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08-08-2014, 06:28 PM
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Preferred pronoun:Maestro
Join Date: Sep 2012
Location: Group W Bench
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Quote:
Rings read "GOE" on the left side of the gap and "TOP" on the right, both in gold type. Looked again for any difference and found none.
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08-08-2014, 08:22 PM
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This may sound odd... But can you feel any difference with your fingertips? It would be on the edges of the ring. If you don't feel any difference, you should be good to go if you install them with the letters up.
Be careful on those oil rings. They are easy to break and easy to forget to put the two piece ring together 180 degrees apart. |
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08-08-2014, 08:29 PM
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Preferred pronoun:Maestro
Join Date: Sep 2012
Location: Group W Bench
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I copped a pretty good feel - nada. I'm thinking I might just go ahead and install them, based on not identifying any differences.
I'll place the gap in the oil ring at zero degrees, and the compression ring gaps at 90 and 270. Thanks for your help.
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08-08-2014, 09:03 PM
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I wish my 14 yr old was interested enough to cause me headaches like that. My favorite moment was when he over torqued and broke the scavenge pump housing. I didn't get mad but it freaked him out. I was just glad he was turning wrenches.
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08-08-2014, 09:10 PM
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Are these the rings you have?
PISTON RING SET - ENGINE - PORSCHE 911 TURBO '78-'92 - STANDARD 97.00 MM - 1.50 X 1.50 X 3.50 MM - PACK OF 6 - GOETZE - http://korihandbook.federalmogul.com/en/section_57.htm#1283
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78’ SC 911 Targa - 3.2SS, PMO 46, M&K 2/2 1 5/8” HEADERS, 123 DIST, PORTERFIELD R4-S PADS, KR75 CAMS, REBEL RACING BUSHINGS, KONI CLASSICS Last edited by snbush67; 08-08-2014 at 10:38 PM.. |
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08-08-2014, 09:22 PM
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P911
Stella
