Cam Shaft Seal:

[JBR]

I'm in the process of assembling an engine. I have one book that says use the paper gasket and no sealer over the rear of the cam between the block and flywheel housing and another book that says to use permatex and no gasket.

What is the best way to seal this area?
Thanks in advance,
JBR

[Rich in Tucson]

I prefer the correct paper gasket with a sealer. I use the lightest possible application of copper spray coat on the gasket to preclude porosity. Original gaskets are 0.009" thick and the horsehoe-shaped flywheel housing shims are 0.009" thick (IT AIN'T A COINCIDENCE) and so if you end up with a thicker gasket (by virtue of what is available or by use of a sealer) you will want to check that you replace the shims with something of similar thickness by measuring the housing run-out. Sealer alone with no or thinner shims is always an option.

[Dave in MN]

I do not use the gasket. I have found a good sealant applied around the camshaft opening seals the area very effectively. I have rebuilt 30+ engines in the last 28 months and have not had a leak in this area. The elimination of the gasket allows you to omit the brass shims at the top of the flywheel housing. I typically use NAPA Even Bead Silicone or Permatex Great Stuff gasket sealant in this area. Good Day!

[JoeWay]

I've assembled dry, with no gasket, the last three times, and then dialed the housing. All three dialed in nicely, so I applied a thin layer of RTV in the gasket area and to the bosses at the top of the housing. Install short bolts at the top of the housing (where the throttle assembly bolts) while dialing in and while the RTV is curing. Allow the RTV to cure 10-15 minutes before assembly.

If the housing doesn't dial in, use a gasket or shims or both as necessary to get it dialed in and be governed accordingly.

Joe

[Mikeinnj]

" The elimination of the gasket allows you to omit the brass shims at the top of the flywheel housing..."

The gasket is designed to prevent oil from flowing out of the rear cam journal opening, and into the flywheel cover. It fits between the flywheel cover and the rear/top of the block. The shims,if used,also fit between the flywheel cover and the rear top of the block.

Why would the elimination of the gasket allow you to omit the shims? I would think the gap created by the gasket removal would require additional shims. Please explain....

[Tom Wesenberg]

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You have 3 machined surfaces, all in one plane, so installing the gasket on the large machined surface means the 2 top bolt machined surfaces need to be shimmed out a distance equal to the thickness of the gasket.

[Bruce of MN]

Originally Posted by Tom Wesenberg

You have 3 machined surfaces, all in one plane, so installing the gasket on the large machined surface means the 2 top bolt machined surfaces need to be shimmed out a distance equal to the thickness of the gasket.

That's the way it worked for me. I used sealer only and had no gap at the top.