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· Registered
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142 Posts
Discussion Starter · #1 ·
Has anyone successfully done it?

seems like it would be a tight situation to o ring it.

dont have a spare block to take down and see if they can o ring it.



sidenote:
if the cylinders were oringed would you use viton rubber orings for coolant and oil passsageways or use a copper or home made gasket?
 

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142 Posts
Discussion Starter · #4 ·
are you talking about a custom machine plate for all 6 cylinders?

i was talking about usging a seperate steel ring for each cylinder


machine shops in your area are expensive 600$ ouch


the only concern i have is the fact of room inbetween the cylinders..

might have to use a plate

Bill
 
G

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It's been done here. Didn't get to see the engine. We talked about it but it seemed to be a PITA. I have seen the car run, and it is SICK!! 28psi/150shot and still holding together.
 

· 2JZ Mk2
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1,396 Posts
I can't see why you would need any plate to cut an oring groove in the deck. We have all kinds of oring grooves (non-engine stuff) machined at work and they are cut with a normal mill cutter on an NC machine usually. I'm pretty sure o-ringed engines just use a stainless wire for a groove around the combustion chamber with a copper gasket. The water and oil passages are sealed by the HG alone from what I've seen. The only issue I can see on a M engine is that the cylinder bores are mightly close together. I can't really see a need for this since a $120 MHG will more than seal the power 99.999999999% of the people make on a 7M.
 

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619 Posts
I talked to someone who did it once, can't remember who.... anyway, they had to make the rings inteconnected, like figure 8's instead of 6 cirles. then they laid a single wire in a zig-zag from one end of the block to teh other, then used small (half circle)pieces too fill in the rest.

GLEN
 

· greasemonkey
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3,341 Posts
my friend had his block o-ringed. it was 6 individual rings and he used a 2mm hks mhg. he was running 22psi and a 150shot wet system. i am thinking of o-ringing the race motor im building. i think it was $360 to have the cyclinders bored, honed, the block decked, and then o-ringed. the hot tank is $40 extra. i havent priced how much for the main saddles to be align honed but figure ~$500 total for block machine work.
william
 

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947 Posts
You could get away with just grooving the block too, rather than a full o-ring job. Should keep the gasket in place in the face of shearing forces too. Heck, might let the composites stand up better too, saving the costs for MHG's in those cases where the boost pressures are not getting out of hand.

Bob
 

· 25psi = 14" brakes :)
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2,348 Posts
If your running a composite HG, just don't get such a smooth RA.
That alone will help clamp your stock HG better.
IF you have a good MHG, no rings or ridges are needed. The gasket will not blow out, especially if you have a stopper type.
 

· Eclectic
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659 Posts
Back from the dead....

A mopar guy at work is trying to convince me to o-ring the cylinders and use a copper head gasket. His reason being that this combo maintains a proper seal in high boost applications where the head bolts stretch from the force and the head lifts from the block.

I haven't heard much about this from any supra owner, but this guy's been around a few blocks so I listen to a lot he says. If any serious techies have some input I'm all ears. Don't give me any "MHG PERIOD" junk.

I just recently read a little bit about it in project MR6 in turbo magazine, they junked it because they were still leaking coolant from the copper HG and had no issues with detonation. I can't remember what they switched to.


couple links I'm currently reading.

http://www.scegaskets.com/techtips/engineprep.html
http://www.supraforums.com/forum/showthread.php?s=&threadid=115735&highlight=oring+and+block
Won't list the rest. There's lots in the non mkiii sections

Baisically what I've found is that it's really only a race only application. They work great for detonation but leak coolant like a sieve if not sealed perfectly, which is a real PITA. Anyone have any first hand knowledge?
 

· greasemonkey
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3,341 Posts
i wouldnt use a copper hg, use a hks mhg. i have seen this combination in action and it works. i will be having my block o-ringed. i found a new machine shop that builds lots of race motors and ive seen there work. my buddy had his engine machined there and it came out awesome. the most important thing in doing this is a competent machine shop. the hks mhg has a 86mm bore which will fit around the orings. most the problems is people useing a standard gasket and the gasket sitting on top of the o-ring and not allowing all the pasages to seal properly. with the hks mhg this isnt a problem.
william
 

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I say go for it. I was told by several machine shops that they would make figure 8's instead of circles.

Around here: if you don't know someone who has done it, it can't be done, right? It's funny how things that have been done for years and years suddenly become the latest and greatest in the import community.
 
G

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I just raised this question with my machine shop. As the HKS MHG basically has a raised ring around the cylinders anyway, they recommended not O ringing.
 
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