To Gasket, or not to Gasket?

[tpripps]

I'm fixin' to pull the rocker covers on my 454 and I wanted to make sure that I had gaskets lined up for putting it back together. But, when I looked in the service manual, it just shows to use RTV. Am I reading it wrong or could I just use some red goo and call it a day? Gaskets aren't that expensive and are available everywhere, but I'm curious to know what the preference is.

 

[dsteelejr]

For valve covers specifically, I use rubber gaskets with Permatex Aviation Number 3 liquid gasket maker. I've never, ever had a leak from anything I've used the aviation gasket maker on, including valve covers, water pump, water neck, and around the water passages on the intake gaskets.

There are good uses for silicone RTV, and when I use silicone I use ultra black or ultra gray. I've used it for making a seal with the intake at the front and back walls of the block and it works great. But for regular gaskets I much more prefer the aviation gasket maker.

If its good enough for airplanes its good enough for my 41 and 48 year old squares.

https://www.oreillyauto.com/detail/c/form-a-gasket/permatex-form-a-gasket-16-ounce-aviation-number-3-sealant-liquid/perk/80017?q=permatex+aviation+gasket+maker

EDIT: I don't have a preference of cork or rubber for valve cover gaskets. I used rubber because it was what came with the gasket kit when I bought my reman 454 and the combination of rubber with aviation gasket maker hasn't disappointed me yet.

 

[Bextreme04]

At least on the GEN VI BBC heads and valve covers, they have a machined surface and use a simple rubber gasket. Works great and no leaks at all. I would recommend using either RTV OR a gasket, don't ever use both. If you use RTV, put a decent continuous bead of a nice thick RTV like the ULTRA or "The right stuff" and then rest the valve cover on the head with the bolts in it to keep it in the right place. Let it set up for an hour or more before tightening in place(the instructions should tell you a more specific time depending on what you are using specifically).

Personally, I would just use a decent rubber gasket with the aviation gasket maker or a similar gasket sealant on it (these are different than RTV).

 

[BillK]

I have never heard of only RTV on a big block Chevy engine for valve covers. Oldsmobile did it on some late model engines but the valve covers had little bumps to space them away from the head the correct distance.

On Big Block Chevys its either a traditional cork or rubber gasket or on the newer engines they use a rubber gasket that actually fits into the valve cover. I personally have never used any type of sealer on them.

 

[DoubleDingo]

Gasket with gasket maker as mentioned.

 

[SirRobyn0]

Yea, Gasket with gasket maker. No 454 that I'm aware of ever came factory without gaskets. I've tried a few different methods, but the old tried and true method that seems to work the best for me cork gaskets, glued to the covers, and RTV facing the engine side. Though it's in regards to the SBC you can see my recent thread titled "valve cover gasket debacle". A fair number of folks posted what has and hasn't worked for them.

 

[QBuff02]

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For any type of valve cover that isn't stock, I use something similar to the above. they are rubber with a steel core, reusable and never leak and although they are a little on the pricey side they are worth the money.

For any stock type valve cover, cork with a little glue is a good fail safe way as mentioned above. If you have stamped steel valve covers, another thing to mention is that you want to make sure the rails of the cover are flat, over the years they've been taken off and put on who knows how many times and usually over tightened in the process and will possibly be warped in the area of the bolt holes. Turn them upside down and lay them on the edge of your bench (the outer lip of the cover will rest on the edge of the bench and the body of the valve cover will hang off the edge) and make sure they are flat and if not, tap the gasket rails lightly with a small flat head hammer from the inside out until they are straight, it's worth the time to check and do. I've also seen many oil pan rails bent and tweaked just enough over the years that if i'm reusing either they get this treatment during the rebuild and installation. It saves on nuisance leaks for sure.

 

[80BrownK10]

For valve covers specifically, I use rubber gaskets with Permatex Aviation Number 3 liquid gasket maker. I've never, ever had a leak from anything I've used the aviation gasket maker on, including valve covers, water pump, water neck, and around the water passages on the intake gaskets.

There are good uses for silicone RTV, and when I use silicone I use ultra black or ultra gray. I've used it for making a seal with the intake at the front and back walls of the block and it works great. But for regular gaskets I much more prefer the aviation gasket maker.

If its good enough for airplanes its good enough for my 41 and 48 year old squares.

https://www.oreillyauto.com/detail/c/form-a-gasket/permatex-form-a-gasket-16-ounce-aviation-number-3-sealant-liquid/perk/80017?q=permatex+aviation+gasket+maker

EDIT: I don't have a preference of cork or rubber for valve cover gaskets. I used rubber because it was what came with the gasket kit when I bought my reman 454 and the combination of rubber with aviation gasket maker hasn't disappointed me yet.

Why are you useing gasket maker and rubber gaskets together? Are you doing like I did when I did my valve covers and just glueing the rubber to the valve cover which is what I did with like 4 or 6 spots on the gasket to glue it and hold it in place when I installed them?

 

[dsteelejr]

Why are you useing gasket maker and rubber gaskets together? Are you doing like I did when I did my valve covers and just glueing the rubber to the valve cover which is what I did with like 4 or 6 spots on the gasket to glue it and hold it in place when I installed them?

I’ve had issues with leaking valve covers is the past. I like the comfort of taking the extra measure of using aviation gasket maker with it.