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Fasteddie313
Joined: 29 Sep 2013 Posts: 2596 Location: MI
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Posted: Sun Jul 21, 2019 7:23 am Post subject: Cutring Head Gaskets |
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Have you heard of these things?
Watch this starting at 4:25 to see what they are.. https://youtu.be/R8PriUgXbe8
Some sort of seperate fire rings with grooves that cut themselves a bit into the head surface.. They even run them over a copper spacer with great success..
I looked for more information on these types of head gaskets and can only really find anything related to the e36 straight 6 engines, but those guys say these cutrings are the best head gasket no question..
But check this out...
You can see in the video that they are separate pieces from the head gasket.. Just some rings..
AND, you can get them in 87mm <!
So, it may be theoretically possible to cut out a 924 head gasket (not by hand) and run these rings the BMW guys rave about on our 924 engines!!
What do you think?
http://www.cesmotorsport.com/documents/94.html _________________ 80 Turbo - Slightly Modified |
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Carrera RSR
Joined: 08 Jan 2010 Posts: 2309 Location: Somerset, UK
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Posted: Sun Jul 21, 2019 7:12 pm Post subject: |
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Unmachined O ringing. There’s opinions for and against O ringing our blocks on here if you search. Some success. Some failure. I personally wouldn’t do it. Once O rings are machined in or in your link, compressed into the head and block, you cannot re use non O ringing head gaskets. Would be too big a dent in the metal to machine out and re use. Just use Cometic MLS for a strong seal. Will work up to 2,0bar boost no problem with ARP studs and properly prepped surfaces. _________________ 1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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Cedric
Joined: 27 Aug 2004 Posts: 2614 Location: Sweden
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Posted: Sun Jul 21, 2019 9:03 pm Post subject: |
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JoakimS uses it in his monster engine, since there were no mls gaskets available back when he built that engine. It have worked for years at his power levels, but i remember him having some issues with oil dripping out the side ouf the head seal. will go mls soon, on my way to remove the head at the moment, got some lifting of the head sadly. _________________ 1980 924 Turbo
www.instagram.com/garagecedric/ |
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Carrera RSR
Joined: 08 Jan 2010 Posts: 2309 Location: Somerset, UK
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Posted: Sun Jul 21, 2019 9:18 pm Post subject: |
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I think that’s a key issue of O ringing if the machining or O ring is not calculated absolutely spot on, you get a solid seal of the cylinders but water and oil channels don’t get 100% sealed and can potentially leak.
My MLS has been fit and forget so far for 4yrs and counting. May last 4 more yrs or 4 more days. Let’s hope it’s the former. But who knows with the abuse it’s gotten over last 20,000 miles and will still get in the future. _________________ 1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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TJC
Joined: 04 Apr 2010 Posts: 828 Location: Central-ish Arizona, USA
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Posted: Mon Jul 22, 2019 12:55 am Post subject: |
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Back in the dark ages, (mid 80's), we used to machine the blocks, (or sometimes the heads), for O-rings using a boring bar or mill. We would form our own O-rings from stainless steel "wire" of a diameter slightly larger than the width/depth of the o-ring groove that we cut to get a proper amount of protrusion that would "bite" into the head gasket to aid in sealing the combustion chamber/bore but still allow the gasket to seal the rest of the surface. Oft times we would use a solid copper head gasket as we wouldn't need to worry about interfering with a standard composite gasket and it's own metal sealing ring and it could be reused by simply annealing it. Since we did this strictly for race engines which were torn down quite often we really didn't run into a sealing issue with water or oil too often but I could see where that might be a problem over the long run as Cedric pointed out in his example.
At the time we would be doing this for engines of American manufacture that were used for drag racing or on oval tracks. _________________ '95 BMW 318i/5 ..."Pearl"
'87 Porsche 944 NA... "Liebchen"
'02 Porsche Boxster..."Sunbeam"
'04 BMW X3..."Xander"
Still on the Prowl!
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Kenodog
Joined: 25 Jun 2003 Posts: 2651 Location: Vancouver,B.C.
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Posted: Mon Jul 22, 2019 2:19 pm Post subject: |
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TJC wrote: | Back in the dark ages, (mid 80's), we used to machine the blocks, (or sometimes the heads), for O-rings using a boring bar or mill. We would form our own O-rings from stainless steel "wire" of a diameter slightly larger than the width/depth of the o-ring groove that we cut to get a proper amount of protrusion that would "bite" into the head gasket to aid in sealing the combustion chamber/bore but still allow the gasket to seal the rest of the surface. Oft times we would use a solid copper head gasket as we wouldn't need to worry about interfering with a standard composite gasket and it's own metal sealing ring and it could be reused by simply annealing it. Since we did this strictly for race engines which were torn down quite often we really didn't run into a sealing issue with water or oil too often but I could see where that might be a problem over the long run as Cedric pointed out in his example.
At the time we would be doing this for engines of American manufacture that were used for drag racing or on oval tracks. |
My old 931 was o-ringed this way. The shop used a fly cutter to make the grove on a mill and then stainless wire was tapped into it. With a standard cheapo head gasket she ran 15psi of hard driving for the 2 years I had it together. Never leaked a drop of oil or water, perfect seal.
Me _________________ 1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140 |
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