Head Gasket 6

[Tioga]

Does anyone know if you need to use a sealer on a new head gasket while rebuilding a 460 Ford motor? If so what is best to use? The engine is a 1986 model and needed new heads because of broken manifold bolts. We need to install the heads with new headers, and the intake. All help is welcomed.

Thanks,
Steve

 

[patprimmer]

Buy gasket

Read instructions

Do what the say

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[evelrod]

In the 50's I followed the 'trend' in what many builders did...that included re using the, for the time, state of the art solid copper head gaskets. After each use, the gaskets were annealed and coated with 'Copper Coat' and let dry, then installed. This worked well on the old flathead engines of the time...I'm not that much of a purist, however! I just changed the head gasket on my 1930 Ford and I installed it DRY. It's 2008, not 1948! Do what Pat says, follow instructions...Gee, you won't even need to re torque on most quality gaskets...In fact, on my race engine head gaskets, re torque is NOT recommended.

Rod

 

[romke]

(metallic) head gaskets are usually meant to be used dry and are manufactured from material that can withstand contact with exhaust gas, high temperature coolant, combustion pressure and engine oil when torqued to the amount as specified by the engine manufacturer. when you introduce another medium on one or both faces of the gasket it is no longer sure that the gasket will be able to perform as expected. the use of sealants with other types of gaskets is usually far less critical and can be advantageous when the two mating surfaces are damaged somewhat or not completely lat.

 

[JimPeop]

You will not need to use any sealer if you are using a good quality head gasket. If you are using a poor quality gasket then you could use a sealer such as Copper Coat but it is not going to make a poor quality gasket perform as a topline head gasket will. If a sealer is used then careful care must be used so that you get an even coat across the faces of the gasket so that you do not get a variance in the thickness that can cause uneven crush loads on the gasket therefore increasing the chance of the head gasket failing.

Jim

 

[dicer]

Only time a sealer is needed is if it is just a steel shim type gasket, like Chevrolet used on older V-8 engines. Most folks just would spray a silver paint on them.
The last 460 Ford I did, the felpro gaskets where coated with a sticky sealer of sorts. Other than those shim gaskets I never use a sealer on head gaskets.

 

[evelrod]

Silver paint may be fine for street engines and low stress applications...Not my first choice (yes, Mildred, I have used silver paint in the past)...there are better sealers available and, cheaply, too. I did many head gaskets on my 1961 Corvette race car in the early 60's, the steel shim type as you describe...I installed them DRY, they have a sealer already on them.

One item I just crossed paths with...the "compression rings".
Interesting that they are still available and even more amazing that there are still engine builders that would use them. We used fine wire to build compression rings on the solid copper head gaskets I described, it's really the only easy way to "O" ring a flathead. Point is, they are, and rightly should be, relegated to the past! Gaskets are much improved since 1948. "O" ringing the block on most engines is totally unnecessary these days...21st Century tech and all that! ;-)

Rod

 

[dicer]

Rod, I always did the dry thing too. Till I had a leak one time. H2O. And yes they have a coat of something on them as a sealer.

 

[evelrod]

As a general rule, at least in my experience, I have found that the "one time failure" of just about anything racing related is most commonly a result of human error. I have had head gasket failure a few times either from incorrect installation procedure or from some related problem such as not making sure all the surfaces are "flat".
I think, looking back, my use of "O" rings, "compression rings" and sealers was a "monkey see, monkey do" sort of thing. I found better ways of dealing with the problems along the way. Part of this is much better head gaskets, I am sure...Part is I'm older and a bit more careful in my assembly. "Do it right the first time and you won't need to do it over" sort of attitude.

See...Even as old, hard headed and, stubborn as I am, one CAN learn (eventually). ;-)

The 'next' project for my Mini is to "dry deck" the engine and 'do away' with the head gasket altogether. Perhaps next rebuild as it will require new pistons as well.

Rod

 

[JohnLear]

"The 'next' project for my Mini is to "dry deck" the engine and 'do away' with the head gasket altogether."

Wasn't it Ettore Bugatti who said (words to the effect); "anyone who needs gaskets can't machine a surface"?

Having worked on a few Bugs I can say that they leak all over the place unless you use sealers (I hear EB turning...), but EB did resolve the head gasket issue by casting head and block as a single unit, i.e. cheating...

 

[patprimmer]

One piece castings for head and block were common during and before Bugatti's heyday. Lithage or white lead was also a common sealing compound. It was quite effective for small gaps, but difficult to remove when rebuilding and quite toxic.

Tioga seems to have not liked my advice. I wonder if it is in essence any different from what everyone else said.

I also wondered why a broken manifold bolt requires a new head. Repairing broken bolts is not all that hard to do so long as you have the right tools.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[willeng]

Interesting reading some of the comments, brings back memories of head gasket woes. One thing years ago that was near sudden death to a head gasket was the quick cooling down of engines behind pace cars. We tried just about every machining technique, sealing compound etc some worked some not especially for long term durability when needed the most & some were near impossible to clean up on rebuild.

There is one OUTSTANDING sealer that ensures long term high stress head sealing & easy removal on rebuild. It will take the heat of battle & remains flexible enough to cope with anything. It can be used on cast iron, aluminium, copper, stainless steel, also can be used with petrol, diesel, methyl benzine, avgas etc. It's oil & coolant resistant as well.
You have to apply firm leverage force to the heads until you hear the seal start to tear when removing the heads.

The product is "ThreeBond WHITE", one tube goes a long way you will not find better, simply apply a "very thin" spread out film with an artists brush on the block side of the gasket, place gasket over studs or dowels & coat the other side & fit heads & torque down. It will spread out very evenly with an even crush.
Just remember to leave a 3-4mm non coated surface around ALL holes on the gasket, it will spread to seal these itself.
We use laser cut S/Steel gaskets with ThreeBond WHITE as the sealer & forget head gasket woes forever & we reuse these over & over again.

As a test once we scored the gasket deeply with a scribe at the bores to see if it would end up failing due to combustion pressure & bugger me it just keeps on keeping on--perfect & no it didn't fail.

Oh, i forgot, you MUST clean the block & head surface with paint thinners first & wipe dry--totaly clean! Do this first & then work quickly & precisely

This product is good.

 

[patdaly]

Rod, there are some of us pushing enough boost to require the "antique O-rings".

Even Cometics has not been able to contain excessive boost...... ;-)

 

[Bribyk]

I don't think there's such thing as excessive boost, only inadequate containment.

 

[evelrod]

Most engines, Pat. I said most engines.
The dry deck system is common on Mini's but at a low 11:1 CR. I intend to use ~16:1 so I can foresee a need to "O" ring the cylinders when using NO head gasket as I plan my dry deck system. I've been using Threebond 1104 for several years to replace most of my gasket applications and as I see it, I may use it, along with "O" rings to replace the head gasket. For now, all the "dry deck" systems I have seen simply block off all the water passages in the head (or gasket) and use the stock type head gasket. With my system, I want to eliminate that 0.035" space.

The only high boost levels(relatively) was my T-coupe at ~22 psi boost levels and ~8.5: CR. It still needed H[sub]2[/sub]O injection on special occasions. I used a stock Ford gasket. On my British race cars I use Payen gaskets (made in England) and, so far, have had no failures using 14:1 CR.

Rod

 

[patprimmer]

Many year ago we used SS shims on SBC used for F5000 motors. We glued them on with high strength Araldite, but for SBC NA I now use the partly SS jacketed inbuilt "O" ring Felpro blues on a clean dry slightly rough flat surface. On a NA motor in a boat they NEVER fail.

I use copper and "O" rings and receiver groves for our blown SBC at 45# boost. We use a bit of Permatex to seal the water passages and don't really care if it seeps a little as it only runs 1/4 mile, but the Threebond sounds like a good tip.

Rod & Pat, I am interested in your thoughts. The blown SBC I work on now we are producing over 40# boost has started pushing inlet manifold to port gaskets into the valley as the floor of the port at the sealing surface is no more than 1/8" thick. This results in a sump full of methanol and the manifold to valley silicone seal being blown then oil blowing onto the bell housing and magneto. I have centre punched both surfaces, checked for even clamp as best I can and glued them to the head with Permatex. Do yo think the Threebond will hold better. There is no room on the head for rubber O" rings on the head in that area.


We currently use Felpro Printoseals, but I also wonder if a cheaper straight grey cardboard gasket glued both sides might hold better as the glue would have more to grip. As the Felpros are failing, we can't reuse them anyway and I feel the printoseal surface reduces grip and does not accept glue well.


Back to the OP.

He said rebuilding a 1986 model 460 Ford. No mention of performance or race. I am sure any good brand gasket installed as recomended will surfice for his needs.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[MikeHalloran]

Pat,
I used to know a guy who made 'no slip' grips for pistols.. out of the gun frame itself. He'd blue and scribe a rectangular pattern maybe 3x3mm to 5x5mm, and at each intersection, drive in a sharp prick punch at an angle, raising a chip... and leaving the chip. You had to peel your hand off the grip to release the gun.

Maybe you could do something like that to your manifold gasket faces...



Mike Halloran
Pembroke Pines, FL, USA

 

[patprimmer]

Good idea Mike.

If my gluing efforts failed I was considering either little pins as stakes or a ledge screwed to the bottom of the port runners to act as a retaining wall for the gasket.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[evelrod]

I don't have much current experience with blown engines so what I have to contribute may not be of much help. I build and race mostly British cars (one Toyota) and I am accustomed to "leaks". It's an uphill battle.

The main problem in racing a Mini Cooper is the joint between the gearbox and the block. It seems no amount of regular sealer, RTV or, paper gasket will prevent 'blow out'. I see several of the Mini racers on the national forum using solid shim copper gaskets...I'm not sure how well they work, but I consider it a bit of overkill. I am using the Threebond 1104 (Google this Pat, they have many other sealers) for my gearbox/engine joint sans gasket. I tried it with the paper gasket once and it failed but with NO gasket it works flawlessly. No leaks or failures in five years.

Now, how this might work on a SBC intake.....The last SBC intake I used was a stamped steel thing on my '61 Corvette about a million years ago and my memory is only accurate for about two weeks!!! :-(

Rod

 

[adrag]

O-rings and copper head gaskets are common on drag racing engines making over 1000hp though the latest trick on nitrous pro mods is to eliminate the receiver groove and let the o-ring simply crush into the copper. There are hollow o-rings available that that are filled with pressurized nitrogen(I wonder how you'd manufacture that) but they're extremely expensive and hardly anybody uses them. The 800 cu in IHRA pro stock engines are starting to move toward the MLS gaskets with I would guess about half the field using them.

Al