Help! what should we use?

A friend of mine is putting together a motor that will have no head gasket. He will be using special nitogen filled O-rings that will seal the combustion chamber. He was wondering how or what he should use to seal the rest of the head with? He must run water in the block and heads. Is there a bullet proof silicone or something else that would work for a water seal? Any help apprecitated. Thanks.

PS. This is on a four cylinder motor that does not have a convetional type deck, it is open around all of the cylinders so rubber O-rings are not an option.

 

The best silicone I have ever used is called "The Right Stuff." I think permatex makes it...but not sure. It's a black silicone. You can get it from lots of places, we usually get it from NAPA.

We use it on anything that requires silicone on our TAFC. We even use it on the exhaust headers and it seems to stand the heat quite well. It takes a little longer to dry, but dries hard when it does.

 

The Right Stuff is the best and I think they make a version of it now called one minute and it dries really quick.

 

The best silicone I have ever used is from the Chevrolet Dealers it's gray in color and cost about 25.00 a tube but it's great stuff.I have never seen anything like it anywhere else and I have flipped wrenches for 30 yrs and I now work for Peterbilt Trucks and we don't have anything close hope this help's Jamie

 

The grey Chevy silicone is UNBELIEVABLE. We have used it for years. I have also used "The right stuff" which, in my opinion is really good also, but still not as good as the Chevy grey silicone.

 

First off, thanks for all the help. I am looking at a 2004 GM performance parts catolog under sealants and I see something called Engine Sealant with a part number 12378521. Looks like it only comes in a tube type size for calking guns. Is this what you are talking about from GM. Thanks, again.

 

A picture of the deck face and head face would probably spark some ideas. What locates the tops of the liners, and how much meat is around the nitrogen rings? Is there room atop the deck to mill for continuous strips of roll stock elastomer? How about welding up the deck solid, and the same for the head passages (to create the equivalent of a dry deck), and then bridge that dry interface with wet external plumbing? Your friend does realize that such rings are notoriously "leaky" until up to temperature?

 

silicone on header flanges

We cracked a header at the races one time,welded it up,put red silicone on it between rounds to get by,cranked the tafc for warmup beside our white trailer,blew little red specks of red silicone all over the side of the trailer.It took me a week to get all that red silicone off the side of my trailer,I'm sure the guy that parked on the other side of me wasn't to happy with me either!!
funny how we remember the little things!!

 

Yes the GM silicone comes in a short syle caulking gun tube.

 

Thanks again for all the advise and help.

My friend bought this motor and it was aready set up this way. The leaky nitrogen o-rings should not be a problem as we warm the motor up to running temp before we make a pass. Last night I asked him how much clearance needs to be filled in when the head is torqued down and he said about .010".

According to GM their sealant can be used up to 1mm which I believe is .039" thick and up to temps of 150 degrees C.

I have only seen this type of sealing with nitrogen o-rings done one other time. It was on off shore BB Chevy marine engines. They o-ringed the deck around all of the water passages. With PSI blowers and carbs they were puting out about 1200 HP. Seemed to work OK for them.

Again thank you for all of your suggestions and ideas.

 

The CJ Batton B4 motor has the same nitrogen filled o rings, you have to look real close with a magnifying glass at them because they crack and all the nitrogen leaks out and then they dont work anymore.

 

i think Mike Moran used those rings on the quad turbo engine a few years ago,but i don't know what he used for water sealant.The gray stuff sound's like the thing honda use on their engines,it's called "hondabond"

 

Such nitrogen rings (Wills rings) are pretty common fare in high end engines. Pay careful attention to the maching tolerances and surface finishes, on both the liners and the head where the rings touch. Dead flat and smooth is the name of the game. Requirements vary according to the specific rings in question. Hopefully you know the source and part number of your rings, and their requirements. If not, I would suggest talking with Garloc-Helicoflex (the likely source of your rings).

Curious, what flavour of BB Chev offshore engine was it that you saw with rings?

Most often, one would machine so that when the head is torqued in place the Wills ring are collapsed by about 20% of their cross sectional diameter, with the head deck tight against either the block or the tops of the liners.

Your friend mentioned a .010" gap, which I am therefore assuming means that the tops of the liners are proud of the top of the block by .010"? If this is so, then you should be able to use almost any sealant between the block & head surfaces, although I would feel better if there was a continuous perimeter channel milled in the block to hold and capture the sealant.

I mentioned "leaky" because it sounds like you have an open deck and floating liners. What you don't want is coolant behind a cold Wills Ring, or else it will invariably weep into the cylinders and cause rust. You need to isolate the coolant from the back sides of the Wills Rings, and make sure that the engine is fully warmed before ever applying a load. Sealant or strips.

A conventional BBC deck is easier to handle with Wills rings, because typically the liquid passages are perimetered with either elastomers or sealants some distance away from the Wills rings. As such, not much chance of getting coolant behind the Wills ring.

I am assuming that this was a running engine when your friend purchased it? What did he find when he took it apart? That would be a good baseline to work from.

 

TOL,
The chevy engines you asked about were made by a well known engine builder whos name escapes me at the moment. The history on the motors? They were built for offshore boats, having a displacement of 360" max. They used Bryant Crankshafts with a stroke of 3.100 and a stock 4.25 bore. Carrillo rods, JE pistons, Brodix heads, PSI 200 series blower, and carbs. This class only lasted a couple of years, then they went to a different motor manufacturer.
I had bought one of these motors, or at least 75% of one. I got the block, crank, rods, pistons, heads, and manifold. No blower, drive, cam, rockers, drysump, etc. I looked at the deck and saw it used no gasket. It still had the o-rings with it. While looking at the deck I saw the o-ring grooves that had been milled in around every water passage that went from the deck to the head. They had even milled a 1/8th inch slot in 4 places on each deck. I thought this might be for some kind of leakage as they did not tie into anything. I ended up selling the motor since at the time I could not find the nitrogen rings.
The motor my friend bought was not together. Well actually he bought two motors. One was turbo charged and it was together. The other was normally asperated and it was apart. He is putting the normally asperated motor back together. It does have special sleeves that tie part of the block and sleeve assemblies together. I will double check on the head to deck clearence, and tell him what you have said about the rings and water. Using nitrogen rings is new to both of us. I appreciate your input along with everyone else.
Thanks.

PS. Sterling built the chevy motors.

 

They make a sealer that I believe is called anarobic sealer. Used when bolting a Camshaft Carrier on a 1.8L GM Engine this stuff works good to. The camshaft carrier is aluminum and the head is aluminum. No gaskets just this anarobic sealer. Just another idea. Kevin