Like to hear anyones experience with o-ringing a block. Never done it before, but I have a brand new Isky O-ring tool and some wire that I want to use on a build. One seemingly obvious question.....do you have to use a copper gasket or does it work fine with conventional gaskets as well? I understand the mechanical process to set the tool up and cut the groove. Looking for experiences with wire type and how high it should protrude. Results others have had when they o-ringed an engine. Water leaks, sealing issues? And would also like to hear from others who did NOT o-ring when adding a blower onto their engine. I'm looking for mild boost on mine in the neighborhood of 5-7 lbs.
I have build several blown 392 Hemi engines and not o-ringed the block. Last I heard the customers were in the 8psi range and no complaints.
If you O-ring the block you should also cut a receiver groove in the head....I haven't had any problems with my blown hemi and my block isn't O-ringed....Mine has 7 thousand miles on it...
On the O-ringed sbc blocks I built, I always used copper gaskets. Blower motors with 7.5 - 8lbs. boost. Never had a problem with them.
Both my y blocks have run 5-8 lbs without head gasket problems. And yblocks don’t have the best head bolt layout or gasket selection. The only blown gaskets I had were from poor engineering on the PCV baffle in the valley pan. Twice on hard dyno pulls we blew a gasket at the fire ring between 7 and 8. The second time we looked closer and found oil in the intake which caused it to detonate apparently. Right above the distributor gear and at 5000 rpm it sprayed more oil than the baffle could handle. Fixed, never happened again. So I’d say not necessary unless it a fun project.
I o-ring every GMC 6 block and head. I use SS o-ring material. It depends if I’m installing the ring in the head or block which direction the gasket goes. The wrap a round on the gasket always goes in the receiver groove. Blocks are easy….heads not so much.
I have built several blown small blocks, never O ringed any of em. One we have run a bunch at the track in a street driven Willys With 10 pounds of boost . It runs 10.20s @ 131 with O head gasket issues.
Overkill on the street. Stud it and go. JMO , We have really good headgaskets now. Blown alky race, blown nitro race, injected nitro race, Yes. Lippy
My last blown alcohol 392 Chrysler had stainless o-rings in the heads, and I cut the receiver grooves in the block with the Isky tool. Worked great!
I used to run small block Chrysler stuff, the blocks were o-ringed with nothing done to the heads. And ran blue Fel-Pro gaskets.
I didn't have any place to rent one, so I bought one for 2 to 300 bucks, in '88. Also, we had a 331 that was built at Keith Black, as an injected Nitro engine, that had O-rings in the heads, but no grooves in the block. We switched it to Blown Alcohol, and tried solid copper gaskets, this is what it would do just whooping the throttle in the shop. I am a slow learner, after we used up all the gaskets copper ones available, I tried sandwich Fitzgerald gaskets, last photo. At the track, I had a couple experts come to our pit, and after looking things over, they said 39 percent overdrive, was a bit much for 336". Those guys were Art Chrisman and Gene Adams. After backing it down to 15 percent, she went almost 193 !
Cometic brand gaskets, no more than 10 psi boost and have had no issues. Machinist said O ringing would be overkill at my level.
So educate me. I know what it is, always thought it was for serious pressures. But, say a guy did it on a 500 HP engine. Would it be a maintenance item to change head gaskets and orings, or would it last the lifetime of the engine?
Back in the 80s, I o-ringed a small block Mopar. SS wire up about .008" with fel-pro blue head gaskets. Head studs too. With over 13-1 cr, it was prone to head gasket failure because there were only 10 head bolts. After that, no more head gasket troubles. The troubles went somewhere else! The O-rings themselves don't need to be changed unless they get damaged
My best guess is that O-ringing the block and the head is the best solution because it eliminates either side having just a flat surface to contend with. I think that would offer the most secure sealing. The number of head bolts has a definite effect on head sealing for sure. I have the equipment to mill a groove in the head. The biggest problem I see with doing that is insuring that both grooves are exactly the same diameter and concentric with one another. While measuring from the locating studs and making the calculations probably isn't too difficult, actually machining 16 grooves the same size and concentric within a few thousandths could be somewhat challenging. If there is a simple way to do that, one that I'm not seeing, I'd be interested. I always think back to the time many years ago when every dollar had a place to go. Bought a new carpet to put in the bathroom (ugh!).......measured it very carefully and made the cut to go around the commode errr....toilet. Took it in the bathroom, flipped it over to install it.........and the toilet hole was where the sink was. The good side was that it made me always (?) remember to think about if the part I'm making will get flipped when installed. I'm leaning toward o-ringing the block but may just go with the Fel Pro gaskets. I'd still like to hear more experiences however, and thanks to those who have already provided info.
Personally, I would not groove both sides. I think it would be asking for trouble. The single groove is enough to substantially increase the clamping (pinching) force at the o-ring, while kinda lightening up on the sealing force at nearby passages. Double o-rings, aside from the concentricity issue, would definitely be overkill, unless the head gaskets were pretty squishy. I would think that extra just might keep the gasket from sealing nearby water passages. O-rings, good gaskets and top quality bolts or even studs should be enough to seal the most obnoxious of engines!
I’m just following along here because I have had some recent issues blowing head gaskets on a BBC with an 871. I was just running GM head gaskets at first but recently decided to change to blue Felpro. Also trying to correct the issue, I had the heads surfaced and it took about .010 to get them cleaned up. Anyway, I put the engine back together but figured if I had any more issues, I would consider o-ringing the block. So, thanks for all the input. I’m hoping I don’t need to do it.
I am with Lawless , on the Chrysler stuff all we ever did was the block. Up around 14.1 and never had any issues. We also used studs.
I'll add that studs are important especially for those engines with only 4-bolts per cylinder like the EarlyHemis but we also made sure to use the proper surface prep on heads and block. The 'roughness' is a big factor in holding the gasket in place and probably the most overlooked. We also coated the gaskets with Copper Coat spray. I would not ring both sides. Good luck.
Not that I'm planning to do it...........but it kinda bugged me thinking about getting the head/block grooves concentric. Let me say up front for anyone who may be comtemplating doing head and block.......IF you make a mistake it will probably be on the heads, as the block bores make it easy to locate the grooves properly. You then have to transfer those locations to the head and that would require measuring from the locating pins to the bores and getting the measurement right.....exactly right. With a CNC mill, you could do it fairly easily, but doing it manually might prove difficult.....but not impossible. The thought came to me (I know some of you believe I don't think rationally )Anyway..........what seemed like a good solution would be to use some thin aluminum or possibly a head gasket and cut it when making the preliminary first cut on the block. The block locating pins would locate it and a little care would allow the groove cutter to cut through either the aluminum or the head gasket before it cuts the block. This would provide an exact pattern to match the block. Then if someone cuts their heads, they can spray dykem blue on the head and lay the pattern in place. Use some more dowels polished undersize on a belt sander to locate the pattern and scribe a line. That provides a visual reference on the head before any cutting would begin. Like I said, probably not gonna do that......but finding a better way was bugging me.
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