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Cutring Head Gaskets

 
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1769
Location: MI

PostPosted: Sun Jul 21, 2019 8:23 am    Post subject: Cutring Head Gaskets Reply with quote

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
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1807
Location: Somerset, UK

PostPosted: Sun Jul 21, 2019 8:12 pm    Post subject: Reply with quote

Unmachined O ringing. Thereís opinions for and against O ringing our blocks on here if you search. Some success. Some failure. I personally wouldnít 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.
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Cťdric  



Joined: 27 Aug 2004
Posts: 1884
Location: Sweden

PostPosted: Sun Jul 21, 2019 10:03 pm    Post subject: Reply with quote

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.
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Carrera RSR  



Joined: 08 Jan 2010
Posts: 1807
Location: Somerset, UK

PostPosted: Sun Jul 21, 2019 10:18 pm    Post subject: Reply with quote

I think thatís 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 donít 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. Letís hope itís the former. But who knows with the abuse itís gotten over last 20,000 miles and will still get in the future.
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TJC  



Joined: 04 Apr 2010
Posts: 707
Location: Central-ish Arizona, USA

PostPosted: Mon Jul 22, 2019 1:55 am    Post subject: Reply with quote

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.
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Kenodog  



Joined: 25 Jun 2003
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Location: Vancouver,B.C.

PostPosted: Mon Jul 22, 2019 3:19 pm    Post subject: Reply with quote

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
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