Cork vs Rubber vs RTV

[Recon716]

Hey guys, fairly simple question here. Cork or rubber gaskets? RTV black works great if you're in a pinch and can't find a gasket, but which of the three is better to use? Why?

[Z-train]

If the rubber gaskets are of good quality,then elephant snot them to the rocker cover and use a skim coart of grease to seal against the head.You'll have years of no leaks.

[Recon716]

I like no leaks... No leaks is good. Yeah I'm just curious, I'm rebuilding/painting my motor later this month. Picked up some rtv and Fel-Pro rubber for the VC. I hear cork is sh*t but I've heard bad and good from both.

[bananahamuck]

Don't use the RTV ,, cork works but it doesn't last forever.

On a tin valve cover ,,such as ford /chevy cork is doomed from the start,, but the Datsun L motor has a pretty wide flat surface so it actually works pretty good.  i put new cork on dry,, don't get me wrong i'm not a never use RTV guy ,, i just don't use it on valve cover.

 

rubber is (or was) more expensive so i don't usually use it.

[datzenmike]

When I used cork in the day I wet it with engine oil so it wouldn't stick so hard when it was time to remove. Pan might work also. Rubber is really petroleum resistant neoprene. Too much RTV inexpertly applied ends up squished inside the head and ends up stuck to the oil pick up screen or in the rad core. Use at your own risk.

Saw what looked like a rubber band in my head water jacket...

 

Ended up with this tape worm...

 

Previous owner must have also been a chevy owner

[Nuclear Water Boy]

Cork breaks apart and falls onto your valve train. Rubber spreads but works but then leaks. Best VC gaskets are the ones made from paper gasket material, the thick stuff not the thin shit. You could actually buy a sheet and cut your own using the VC as a template. Just apply some paint to the VC gasket area then press down onto the gasket material. This is how I did it before then use a good straight edge and box cutter and hole punch.

[Z-train]

If the rubber gasket is elephant snotted(3M trim adhesive) to the cover and a film of grease is applied to the lower surface,it will not leak and will hold up indefinitely.

[Nuclear Water Boy]

They do last a good long time but I've used rubber VC gaskets before and though they can last mine didn't. But likely due to the nature of a good spec cam setup that required frequent valve clearance/adjustment checks which over burdened the gasket with multiple retorqings plus gooping the surfaces eventually will in itself cause a leak unless you keep it really clean. Went to the thick gasket material and they had some leggs. One thing you also may want to do is flatten your VC gasket surface. I've done this using a good thick piece of glass (still got it for rocker arm reconditioning) or anything that is truly flat then spray adhesive some 400 wet & dry paper to the glass. Use machinest blue or a sharpie and color in the VC gasket surface and proceed to flatten the surface. Works everytime and you'd be surprised sometimes at how warped that surface can be.

[banzai510(hainz)]

FELPRO VALAVE COVER GASKET IS GOOD

[Scgreen620]

I heard there's rubber cork ? Might be wrong