Head gaskets for blown BBC

What are you guys using for BBC. If you use copper & 'O' ring the block ,what brand head gasket do you use. How often do you aneal them & what is the method you use? How much success has anyone had with the Cometic gaskets?
Thanks in advance.

 

I've been down the head gasket problems, I feel like I've learned alot in this area.
We run Clark copper head gaskets and o-ring the blocks. We have never annealed.
If your having problems, I recommend;
1-make sure everything is flat
2-make sure the surface finish is smooth enough (for copper)
3-retorque after a new gasket is put through a few heat cycles
If your still pushing them out, then;
4-make sure the problem isn't your fuel system
5-add the inside head bolts as your probably pushing the gaskets out at cyl#2and/or 7
Comments;
I have in the past put a receiving groove in the head. I accidently put a fuel shutoff valve together backawards and within a couple seconds into the run blew the gaskets out and tore the receiving groove out. (the head gasket maybe a good "psi release", if its not the gasket than what is the next weak link)
I'm now seeing signs of loosing combustion psi and am contemplating wire in the head and receiver groove in the block.
We're making about 1600 HP with very few signs of detonation.
I could never get Ø1/2" studs to do me any good, I'd still push'm out.
If faced with thinner or thicker copper gaskets choose the thicker, they conform to irregularities better.

 

my block is o ringed ,not the head and i use copper coat on both sides of the copper head gasket....its like glue!....never had a problem

 

Head Gaskets

O-rings in the head and receiver grooves in the block. SCE copper gaskets, annealing is ancient history with the new gaskets. I have re-used gaskets as many as 4 times in a pinch and have taken them as high a 40 psi, never had a failure.

Never needed to put anything on the gaskets, (Dry Block) Hylomar around the water passages if you are running water.


Corey

 

BBC head gasket

be sure you use the valley bolts.
Clark Gaskets, be prepared when you call them, they will make just about anything you want, they will make any bore size you want. water or none water. I found the gaskets squeezed into the bores on the last motor I had SCE gaskets on when I took it a part, so I went back to Clarks
I have motors both ways, o-ring in the head, o ring in the block.
Never had a problem with either.
If I had a choice the O ring in the head is the way to go with the receiver groove in the block.
with the o-ring in the head
you will have to pry the the gasket out of the receiver, it really seals
if you have aluminum heads and put the o-ring in the block the head receiver groove with gradually "mash" out the sharp edges so it will not seal as well.
I run gaskets basically forever, as long as they go back in the same place with the same block and same head.
Check your head torque after the first couple heat cycles.
I have run .032 with out a problem, but the thicker gaskets .062 you should have less problems with blowing.
I run 70% over and about 38# of boost. With Oddy prepared Kobelco 8-71
Richard Rockefeller
www.Policypeddler.com

 

we run a hemi ta/d....but I have a blown bbc in a flat bottom boat and I run the felpro head gaskets with never a problem...BUT we dont run this thing like a race car 30% over 7,500 rpm's Dave
www.myspace.com/daveloweswr

 

I was at Bob Rosetty's a few months ago. The brand name of the heads on his Tweety's Rat blown alcohol nostaliga funny car is on the tip of my tongue. Donovan block with extra holes in the deck. Pipe plugs in the intake runner roofs, holes that are drilled, then counterbored in the bottoms of the runners for the extra bolt heads to sit in. Looked like the way to go with a blown Chevy that didn't come with valley provisions.

http://www.draglist.com/artman/publish/daily_pictures/article_001456.shtml

 

Thanks guys, as Policy Peddler said , we run O rings in the block with reciever grooves in the head & the area were the reciever grooves meet between 2 cylinders has blown away slightly leaving about 1/2" were the 2 O rings join together missing. We put a new set of copper gaskets @ .062" thick which only done 3 races on a circuit boat & leaked 40% on 2 cylinders .These were the cylinders that had a peice blown away between the 2 reciever grooves. What should the depth of the reciever grooves be, as these look to be maybe .025" - .030" deep. Just wondering if the grooves were say only .010" deep whether it would better seal the area were the piece is missing?

 

ignore the leak down when the motor is cold.
heat the motor up then check it, aluminum expands a lot, you will see them leak cold then seal up when warm.

If the O ring is leaking once the motor is running you will at least see the gasket blackened and probably have it blown out before long. remember it is not an oil or a water leak that just keeps weeping, it is hot gas and it will torch through the gasket if it is in fact leaking much when it is warmed up.

put O ring in head and receiver in steel block or liner, that has already taken care of the leaks i have seen, the gasket pushes into the bottom receiver groove and absolutely seals it.

without checking my liner O ring must be about half or a little less than the diameter of the wire, or the wire would not stay in when you put the o ring in the liner.

If you "really" want to be sure, put an o-ring in both the block and the head, with one just a little bigger than the other.

Call Clark head gaskets and talk to them, they are happy to help with suggestions and tech.

The only question I have, are you sure your heads and block are "flat".

 

Policy Peddler, They are flat. I am concerned about the area in the head that has the reciever grooves. The 2 grooves come very close between the cylinders . In this area there is a small area of about 1/2" were the 2 grooves are joined because a small amount of the head between the grooves has disapeared. I would think that this gives an area were the copper from the O rings isn't being pressed in tight into the reciever grooves as it has a bigger area for the copper to go therefore not a tight seal & allowing the leakage. It is also my understanding that the reciever grooves should only be around .010" deep. The O rings in the block should stick out about 25% the thickness of the wire. Our reciever grooves are around .030" deep.

 

Head Gaskets

Sorry to Hi-jack this thread but I have a quick question. Is it better to put the receiver in the head or the block. I have always put the receiver in the block but the previous texts have made me re-think that concept.

Thanks again for the info


Corey

 

Hello MKR 588,

You are correct your grooves are probably way to deep. As you mentioned you only want the wire to protrude approx 25% of the thickness of the gasket although on the .062 you could probably to to 28% no problem. As far as the reciever grooves you only want them to be 75% as deep as the protrusion of the wire above the block ( or head if you are o-ringing the head and grooving the block).

If you go any deeper than 75 pecent of the protrusion then you have lost the clamp load of the wire in the gasket and negated the whole process. Another thing that has not been asked is if you have an aluminum block and head? if you do then you have pretty equal expansion rates so the reciever groove is not under any shear load, when I had my last motor Bowtie iron block I o-ringed the block but left the heads alone as my thoughts were that the head had to slide on the block as it heated and cooled at different rates, this was just my feeling on this many people think its crap and run grooves with dissemalar metals with sucess just as I ran mine without grooves with sucess.


Richard Gavle

 

Thanks Richard, as mentioned we are running .062" gasket with .040" O rings in the iron block protruding around .010" - .012". The reciever grooves are in alloy heads but I'm thinking like you mentioned that they are too deep.At a guess the reciever grooves look to be at least .020" - .025" deep It looks like the gasket isn't clamping on the raised part of the gasket that is pushed into the reciever groove. Because the reciever grooves are very close there is the part of head that is between the grooves which has either broken or blown away which has joined the 2 grooves together approximately 1/2" in length which makes the problem of sealing the gasket even worse as the copper has too big an area to squeeze into. I dont believe that the problem will go away with a warm engine but I dont want to try as this thing is all apart, yet not sure how to fix it. Perhaps facing the head will help to reduce the depth of the reciever groove or as mentioned put an O ring in the head as well. Whats your thoughts.

 

We use Clark's .041 wire, which is in a .039 wide groove and about .025 deep. So I have .016 sticking out.

Groove diameters:
We've had grooves that "figure 8", so the diameters are 4.840 on center and you have a total of 3 pieces of wire per bank. This leaves 1 wire inbetween the cylinders.
But "normal" to me is cutting the groove at 4.800 on center, so inbetween the cylinders the wires touch each other. There is one wire per cylinder.

 

It's common for the Chevy guys to put the wire in the cast iron block. Some people have problems with receiver grooves in the alum. head. The edges of the groove are "weak" alum. so they break off. I've had this happen.

It's common for the hemi guys to put the wire in the alum. head and the receiver groove in the steel cylinder liner.

It's my perception that wire in an alum. groove and the receiver in steel/cast iron is the strongest, although none of my stuff is that way. (it might be next yr as I'm seeing signs of escaping cyl psi)

 

Sorry for the late reply I have been away from the box...As Sodak said I also had the wire in a figure 8. I feel that the aluminum is to weak to groove for the reciever particularly with an iron block due to the head moving around in relation to the block.

I would either leave the wire in the block, although I would run larger wire that will penetrate the .062 gasket 25% and mill/weld and mill the head flat. If the previous setup held for long at all this should suffice for most moderate boost situations.

On the other hand if you want to run with the big dogs

and you want to go with the wire and groove then repair and wire the heads and groove the block/sleeves this groove should be twice the thickness of the wire and 75% as deep with well defined edges to allow the gasket to be deformed and clamped between the valley of the groove as well as held from moving by the edges of the groove. It is imperative that the reciever groove be well aligned with the wire and head for optimal results.

 

Are the hemi's setup where the cyl. sleeve actually sticks up above the deck surface a tiny amount? Almost like a fire ring on a diesel.

 

What kind of boat do you have? I have a Mako runner bottom that will campaign in the Pro Eliminator (8 seconds) class this season with a blown alcohol BBC.