roy69

I know this has been discussed in a number of threads -- most of those threads centered on laminated and rubber coated gaskets.

I will be installing new valve covers, for fresh chrome, not for any other reason. I have no leaks on the existing covers. I havent pulled the covers yet, but the ones in place appear to be cork. I am thinking of either replacing with cork or the cork/rubber gaskets from Felpro. Thoughts / Opinions?

vette400

I have always used the cork and have never had any issues out of them. Just make sure to use a consistant torque to all the bolts. 39inch pounds if I remember right.

billla

I have always stuck the cork gaskets to the cover, then used no sealant on the head side. Biggest thing is that the flange needs to be flat, and the bolts must NOT be over-tightened. No torque wrench required, just snug them down lightly (with the spreaders) and you're golden.

Just an FYI...budget chrome covers typically have a shallow lip on them and are NOT flat on the flange, which makes a leak no matter how you do it.

Snoopysvet

Consider aluminum valve covers for no leaks

jcloving

I use felpro rubber coated steel gaskets. I also use silicone between gasket and cover and gasket and head. The Felpro gaskets I get come with longer spreaders too.

I install them and lightly tighten the bolts. The next day I tighten them down all the way.

This strategy has worked well for me. No leaks.

7T1vette

For new, chrome covers, you need to scuff-up the surface that mates to the gasket in order for it to seal. 150-250 grit sandpaper will do the job. Just don't scuff it in only one direction; scrub it around a bit to get a 'random' sanding pattern.

The chrome surface is too slick and is difficult to get to seal without getting super clean and using sealants.

roy69

Thanks. For the 427, the only spec I could find has them at 50 in-lbs. Do you use any sealant or adhesive - or just clean/dry surfaces?

I do have some concern with that as I did go "budget". I'm hoping to avoid spending $400+ on the "original" replacement. If I can't get them to seal, I will then go that route.

I should have noted in the post that this is a BB and the original covers are flash chrome steel and I want to keep it looking somewhat original.

That's a great tip - Thanks!!! I would not have thought to do that.

Mashman

This is what I do.

With a clean surface on the covers, put a small bead of RTV all the way around. Then put on gasket. Make sure the holes in the gasket line up with the holes in the covers. Place on workbench with gasket side down. Let sit overnight.

Put a small continuous bead of RTV on the gasket, and then place on head. Start the cover bolts, but only use them to make sure cover is properly aligned - don't tighten the bolts. Let sit overnight.

Hand tighten the bolts with a nut driver. For a couple of weeks. everytime I take the car out, check to see if bolts need retightening.

Ironcross

The cork/rubber Felpro gaskets are very good and they can be used over and over if applied correctly.....no trick as long as your using a hard setting glue such as 3-M trim cement either yellow or black.. Naturally use clean parts and apply the cement completely around the valve cover lip allowing it to set and get real tacky......then place the gasket on the valve cover with any loose weights laying around insuring the gasket wont move until they become dry..... put them on without the worry they can get get moved by rocker arms or anything else while replacing them that you cant see..

roy69

RTV would seem to be the product made for an application like this, however, some of you prefer to use trim adhesive. What is the advantage of adhesive over RTV?

marshal135

I recently posted similar question and received good info.
I chose the Felpro #1635's for my 427.
I too have the poorly flash chromed valve covers.
I spent allot of time per advise from here on geting them flat.
I cleaned both surfaces well & used a little acetone on the head surface to degrease.
I installed w/o any goop. The silicon ones have stops in the bolt holes to prevent over tightening.
Mine are leak proof so far
Marshal

gofastvette

Silicone/RTV, are both gaskets by themselves...But silicone used as a sealer to hold a fiber/rubber gasket of any brand is a not a good idea as the gasket is never solidly glued to the valve cover. And when installing the cover a soft setting adhesive is prone to move if you strike some object as rockers or whatever that can become leaks...

PS.don't use sealer on the head

Tim H

As usual I do totally opposite of the rest of you all and use ultra black on the heads and apply the cork gaskets to them and set the valve covers on dry and snug down and never have any leaks and can take them off several times with no problems.
I seem to think the old gaskets come off the surface of the head better than the valve cover.

7T1vette

Silicone 'sealants' do not work well with oil/petroleum fluids. If you get them to seal, they will stay sealed. But, it can be difficult unless you consider other factors.

RTV Ultra Black is made to seal oil/petroleum products. Good stuff.

Cork will seal fine. But it will dry out over time. Cork/neoprene composition gaskets will seal and will NOT dry out.

Slick metal surfaces are hard to seal, unless they are squeaky clean and/or have been 'scuffed'.

All sheet metal covers need to have flat (un-dimpled) gasket rails or they will not seal. Overtorquing a sheet metal cover to "make" it seal....won't. It will just leak worse. The less torque required to make a sheet metal cover seal, the better.

Retainer torque is the least desirable factor to employ when trying to get valve covers to seal. There is no oil pressure inside the cover, so retaining "force" is not really necessary (there can be some low level of crankcase pressure that can be problematic, especially if you don't have a working PCV system on the engine).

Sealants and adhesives will help when you are having difficulty sealing a cover gasket without them. But, if you use a cork/neoprene gasket, have a flat cover surface [that is not too slick], clean both mating gasket surfaces of all oil/grease/paint/dirt, use torque spreader washers on stamped covers, and apply specified torque to the retaining bolts/screws, you should not have any need of sealants.

Them's my 'tidbits'....

drwet

My experience is with small blocks but I'm sure the principles are the same. I use rubber cement (the stuff you use for weatherstripping) between the valve cover and the gasket. I don't like RTV silicone. In my experience it makes the gasket slippery and it can move while you're torquing it down. Use those washers that distribute the clamping force over a larger area of the valve cover, and retorque every few weeks. I agree with the guys who say tighter isn't better. Just snug, but keep retightening them from time to time to make sure they stay that way.

Jack Wood

Regular thickness cork leaked at the back corners. Thicker one solved that using yellow 3M weatherstrip cement between valve cover rail and gasket with nothing on the cylinder head side. Glue the gasket to the cover and drop four bolts through the holes to hold it while it sets up for about an hour or two then install covers on the heads. Cakewalk.

Tim H

how do you get the old gaskets off in a few years when they crack?

7T1vette

If you buy Fel-Pro cork/neoprene composition gaskets, they won't crack....

gofastvette

VS-12869-CE, cork/rubber under $20.00

drwet

Scraper & scotchbrite pads. The nice thing about gluing the gasket to the valve cover is you can work on it on the bench and not get bits of gasket and adhesive in the engine.