Silicone rubber valve cover gaskets?

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Jan 23, 2014
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Hi guys,

Just wondering if silicone rubber is a good material for valve cover gaskets?

I ask this as I have heard they are more prone to leaking that normal rubber.
 
it doesn't matter what it's made of. If the valve cover gasket leaks, go ahead and replace it. OE part is probably the best. Name brand aftermarket also works.
 
Silicone is less likely to need re-torqued later. That's about it. Both work fine, though given enough time (years), you may have to retorque or replace either if you're picky about small leaks.
 
Some cars use RTV for the valve cover - but in many cases it's molded rubber with RTV to seal the corners and half-moon plugs. Use the OEM gasket or a known brand name. Don't forget to replace the plug tube seals, you have a Japanese OHC engine.

I know Fel-Pro does offer a silicone or FKM PermaDryPlus upgrade for some engines that use a cork-rubber gasket(mostly American OHV engines).
 
This is a perfect example of when specific product names should be used.

Too many products have silicone in them nowadays.

Products like Permatex Grey sealer and Ultra Black (just to name two) have silicone in them and need to be specified.
 
Excellent material. I bought a pair for a Gen 1 small block Chevy six years ago and have had the valve covers off at least 10 times. You probably don't want to do that. Fel Pro blue silicone. Not cheap but they still don't leak. First I had clearance issue with roller rocker arms and then I did a cam swap. Cam kit came with a stuck lifter and it took a while for me to figure it out.
 
Originally Posted by Randy_R
Excellent material. I bought a pair for a Gen 1 small block Chevy six years ago and have had the valve covers off at least 10 times. You probably don't want to do that. Fel Pro blue silicone. Not cheap but they still don't leak. First I had clearance issue with roller rocker arms and then I did a cam swap. Cam kit came with a stuck lifter and it took a while for me to figure it out.

ou running a Solid can in that .030 over 350? Or just backing off the lifter preload to a 1/4 turn HOT?

I usually run the legendary GM 222 cam in stick cars. I haven't beat it yet for a flat tappet
 
Originally Posted by Charlie2015
it doesn't matter what it's made of. If the valve cover gasket leaks, go ahead and replace it. OE part is probably the best. Name brand aftermarket also works.


It does matter, there's a whole bunch of science behind elastomers. Typically FKM would be better at chemical resistance (like acids) than silicone. There's chemical compatibility tables that reference this sort of stuff.
 
I think the OP is talking about valve cover gaskets made of silicone rubber, not talking about using a silicone sealer on top of a (regular) valve cover gasket.

Yes I would definitely use a silicone valve cover gasket. Silicone holds up well to chemicals/solvents, heat, cold, age, etc. Maybe other materials (FKM?) that hold up better to chemicals but silicone is very good. Valve cover gasket is a good application for this material.
 
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