Installing composite head gaskets

[Gary-UK]

So I have always used composite head gaskets with Aluminium heads(through choice and I know copper are available and dont want to start a copper vs composite thread) and have always fitted them dry.

I have always found they stick extremely well and are a pain to clean off when you pull the heads. In fact cleaning the remnants of gasket off the block with all the studs in has to be one of the worst jobs on a flathead.

So I was reading the blurb on the Best gasket site today and came across this...

Install GraphTite™ head gaskets using using a spray-on sealant like K & W Copper Coat or Permatex Copper Spray-A-Gasket. Always re-torque, no short-cuts.

So what am I missing? Why does the composite need a sealant when they stick so well? Or is it to make them easier to clean off LOL.

[FRANK PKNY]

I have done it both ways. MHO is they both work if you carefully retorque there should no be any problem. I have also used the K&W copper spray on copper gaskets on T,A, and V-8's although I personaly don't think they seal as well as the modern composit. Thats just my opion and I'm sure there will be those that don't agree with me. Like they say in Brooklyn "Get otta here." Frank pkny

[Lyndon]

I used the composite head gaskets on my '36 engine, and on re-torquing it appeared that the gaskets were squishing out a little at the sides of the deck at each stud location. The engine appears to start and run fine, so I am assuming that everything is ok but I have to wonder about it.

Has anyone else seen this on their engine builds with the composite gaskets?

[Henry Hopper]

Gaz, every time I read or search out info on Flatheads, I find conflicting imformation...there really does not seem to be a definitive rule book once you deviate from stock specs....btw, your car looks the mutts` nuts....I`ll take a ride over to your place once I get a few things finished on the roadster....looking forward to going through the Mersey Tunnel and hearing my motor through the Porters lol.

[Flathead Fever]

I use Felpro composite gaskets, this is what Edelbrock recommends for their aluminum heads. Most modern engines have cast iron blocks and aluminum heads just like our Flatheads equipped with speed equipment. Millions of dollars have been spent researching composite materials that can cope with the different expansion rates between cast iron blocks and aluminum heads. These gaskets come with sealer on them and should not require any additional sealers. I believe they are far superior to the 100-year-old copper gasket technology. These new composite gaskets can last for hundreds of thousands of miles in modern cars.

Make sure both surfaces are clean so the factory head gasket sealer can do its job. Always use hardened washers under the nuts so the nuts do not gouge into the soft aluminum heads, the washers will also help the nuts retain their torque. Modern head gaskets are not supposed to require re-torqueing but it is a good idea to do it anyway. Torque the heads using the correct sequence, fire up the engine and let it reach operating temperature and then allow it to cool down. When I re-torque the heads, I usually find that they will turn another quarter to half turn.

The head gaskets do not usually leak, it's the threads in the block for the studs that most guys have problems with. Make sure you apply lots of sealer to these studs, I think all but a couple of them go straight into the water jackets. I also like to put a slight coating of antisieze on the sides of the studs to help removal of the heads should it be required in the future.

Always use antifreeze to prevent electrolysis.

[Lyndon]

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I'm starting to wonder if I might have a coolant leak into the oil pan. The oil level seems to have risen (unless it is my imagination) and the oil on the dipstick appears like a chocolate milkshake. I wonder if those squishy head gaskets are leaking coolant down one or more cylinders into the pan on me? I'm going to drain the oil and see if any water is in the bottom of the pan.

[JWL]

There is a huge difference between the old Flathead composite or copper gasket and those used on modern, bi-metal, engines. Just recently a Flathead gasket using modern MLS (mutiple layer steel) gasket technology has been introduced. They are VERY expensive but are constructed to withstand thousands of cycles in a bi-metal engine. As a practical matter, it would be unusual for any of our Flatheads to be cycled to the degree required for MLS gaskets to be a worthwhile investment.

Search Cometec gaskets if you think you need the proper gasket design for your bi-metal Flathead engine.

[G.M.]

Lyndon, you don't have to drain the oil to see if there is water in the oil pan. When the engine sits over night the water willl go to the bottom. The oil on the stick will be clear with a few water bubbles on the bottom of the stick. When you start the engine the water is churned into the oil and looks like a grayish brown milk shake. Let the engine sit over night and just loosen the pan nut enough so the water will drain off the bottom when oil starts to come out close the plug. You didn't mention what year your engine is, the early engines have 2 freeze plugs on the bottom edge of the block or pan rail on each side where the pan bolts on. These can be identified by two buldges on the side of the block just above the pan. Often when the freeze plugs leak if you look real close with a flash light you will see a little moisture or water at the seam where the pan meets the block. G.M.

[Lyndon]

Thanks G.M. My engine is a '36 LB, and has those freeze plugs. They were replaced with new welch plugs when I had the engine all apart. I will check for water as you suggest. I sure hope it isn't those freeze plugs that are the cause of this, at this point replacing the head gaskets would be the lesser of the evils.