[v8hed]

I've read on here not to use sealer on these gaskets because they're rubber-coated. However, on the instructions that come with the gaskets, it states to use sealer on both sides IF the surface finish of the block or heads is rougher than 60RMS. So, I'm thinking it might be prudent to use sealer in ANY case, just to be safe.

If this is the case, what sealer should I use and how should it be applied (how thick, etc)?

Comments?

Cheers,
Ian.

[F-BIRD'88]

Why do you have to read in to some thing more than what it clearly recomends.

Clean dry, and oil free is what is recomended. This is what I have always used and have never had a failure even at 12.65:1 compression ratio.
clean the block and head decks with lacquer thinner.
New GMPP head bolts are recomended. torque to spec in 3 steps Retorque after engine break in. The new GMPP head bolts with a smaller head bolt size allow you to retorque the head bolts after break in without removing any of the rocker arms. use a small amount of RTV gasket sealer on the head bolt threads and under the head bolts.
Nothing else is required. Leave all the other glup and gunk in the tool box.

Any kind of "sealer" between the head, gasket and block acts as a lubricant, allowing the head and gasket to float on the block. This causes head gasket failure.
The head and gasket must grip the block and not move to stay sealed.
CLEAN DRY and OIL FREE

[v8hed]

Originally Posted by F-BIRD'88

Why do you have to read in to some thing more than what it clearly recomends.

Clean dry, and oil free is what is recomended. This is what I have always used and have never had a failure even at 12.65:1 compression ratio.
clean the block and head decks with lacquer thinner.
New GMPP head bolts are recomended. torque to spec in 3 steps Retorque after engine break in. The new GMPP head bolts with a smaller head bolt size allow you to retorque the head bolts after break in without removing any of the rocker arms. use a small amount of RTV gasket sealer on the head bolt threads and under the head bolts.
Nothing else is required. Leave all the other glup and gunk in the tool box.

Well, the instructions clearly recommend to use sealer on both sides of the gasket if the surface finish is rougher than 60RMS (no idea what that means in real terms). But, your experience is good enough for me. Thanks.

[F-BIRD'88]

Aluminum heads require the use of head bolt washers under the head bolts.

[ceh383]

Originally Posted by v8hed

rougher than 60RMS (no idea what that means in real terms).

RA (roughness average), RMS (roughness mean surface), and AA (average area) all expressed in micro-inches. To convert RA to RMS multiply RA by 1.11.

More info HERE if you really want to know.....

[Rick WI]

An excellent head gasket spray is sold by Chrysler. The local dealer will have it. Excellent stff.

Follow the recommendations from Fel Pro. They make the damn things.

[machine shop tom]

For the 1094 head gasket to seal the head and deck surfaces must be flat. Make sure that at least the heads are milled so that at least one surface is known to be flat. Heads that are new are not necessarily flat.

tom

[v8hed]

Originally Posted by machine shop tom

For the 1094 head gasket to seal the head and deck surfaces must be flat. Make sure that at least the heads are milled so that at least one surface is known to be flat. Heads that are new are not necessarily flat.

tom

Yea, my heads are currently with a machine shop having a 'clean-up' skim (~0.003"-0.004") for that very reason. I'll just make sure I clean the block mating surfaces as good as I can with carb cleaner and a scotchbrite pad.

Cheers,
Ian.