Premium silicone head gasket

[bobt]

I'm doing a valve job on my stock 1915 touring and I have a new premium silicone head gasket that I ordered some time ago when the copper ones were not available. I was thinking of using it now. Has anyone had any problems with this style of gasket? Langs still sells it. bobt

[Craig Leach]

Hi Robert,
The only issue I have had is they tend to stick to the head & block when you remove the head the next time. This makes it a little more work
scraping the gasket off the head & block. I attribute this to they recommend not using any sealant on them. ( I use cheap silver spray paint on
copper & they come right off ) They are also not recommended for use with a Z head ( my impression is they are not recommended for aluminum
heads at all ) For the most part this style gasket is what everyone uses on engines made after say 1955. They can not be reused like copper.
Craig.

[Kevin Pharis]

I ran a couple of these gaskets on my speedster with aluminum head and had no problems. Head and block surfaces must be flat and clean, and fire ring must have good contact all around. Install without any sealer (copper coat, aluminum spray paint, etc…).

Side note; these gaskets are far less work to modify for oversize valve clearance. Simply remove the fire ring, use tin snips to trim filler, reshape fire ring, and reinstall fire ring. Takes about 10 times longer to modify a copper clad

[Kevin Pharis]

They are also not recommended for use with a Z head ( my impression is they are not recommended for aluminum
heads at all )

I believe the Z head issue has to do with combustion chamber shape not allowing the fire ring to make proper contact

[Jerry VanOoteghem]

A fellow chapter member used the silicone gasket with a Z head. It failed miserably. His coolant ran low before he was aware there was a problem and he consequently also cracked the Z head from overheating.

[Craig Leach]

Kevin,
That's good to know. I stand corrected on the issue of other aluminum heads. Thanks.
Craig.

[bobt]

When you reuse a copper gasket, are there any special steps? I'm talking about the common copper sandwiched gasket that Lang's sells. bobt