340 intake gasket replacement guidance

[RustyRatRod]

So edelbrock recommends putting gasket sealant along the whole intake mating surface? Is it really needed since its just sealing for air? I mean i understand putting rtv or gasket sealant around the 4 water passages, i guess having it on the whole intake mating surface cant hurt right

I don't know what Edelbrock recommends. Where did you see that? All I recommend is RTV around the water passages only, on all the bolt threads and the china walls.

I will say this. Normally, @missing linc is 150% right. Gaskets and RTV don't go together most times, but IMO, gaskets sealing around water passages can be an exception. Sometimes, RTV can act as a lubricant and cause the gasket to squirm out from under the parts being torqued together and cause a leak. Since the intake gaskets have many bolts going through them, that's not possible, so I always use RTV around water passages only on the intake gaskets.

 

[RustyRatRod]

so i should put a skim coat of rtv on that whole surface?

Yeah. LOL. Ok I read the PDF file. Notice what they said. They said put Gaskacinch on the gasket surface. That's an Edelbrock product. Sneaky marketing gimmick. I would never in a million years put sealant on the entire surface. Just around the water passages will suffice. Just my personal opinion.

 

[71DodgeDemon340]

Yeah. LOL. Ok I read the PDF file. Notice what they said. They said put Gaskacinch on the gasket surface. That's an Edelbrock product. Sneaky marketing gimmick. I would never in a million years put sealant on the entire surface. Just around the water passages will suffice. Just my personal opinion.

Thats what i was thinking and always follow, if its air i let the gasket seal it, if its water or oil i usually use #2 permatex if it has a gasket

 

[RustyRatRod]

Thats what i was thinking and always follow, if its air i let the gasket seal it, if its water or oil i usually use #2 permatex if it has a gasket

#2 USED to be really good. Lately, I've seen it dry out and get flakey. You seem to like it. Use it if you want, I'm just letting you know what I've seen in the past few years. I think they changed the formula somehow. Whatever you decide to use, good luck with it and keep us posted!

 

[71DodgeDemon340]

#2 USED to be really good. Lately, I've seen it dry out and get flakey. You seem to like it. Use it if you want, I'm just letting you know what I've seen in the past few years. I think they changed the formula somehow. Whatever you decide to use, good luck with it and keep us posted!

its is usually my go to, i use it a lot at work and more specifically the versa chem brand. I may just use the ultra grey gasket maker around the water passages since thats most likely what i will use on the china walls. How far over the china walls do you usually go with the rtv?

 

[missing linc]

its is usually my go to, i use it a lot at work and more specifically the versa chem brand. I may just use the ultra grey gasket maker around the water passages since thats most likely what i will use on the china walls. How far over the china walls do you usually go with the rtv?

3/8 to 1/2 inch is what I typically do.

 

[RustyRatRod]

its is usually my go to, i use it a lot at work and more specifically the versa chem brand. I may just use the ultra grey gasket maker around the water passages since thats most likely what i will use on the china walls. How far over the china walls do you usually go with the rtv?

I use a bead about 3/8 of an inch tall. You want it tall enough to contact the intake really good and make a good squish seal. I always let it sit 24 hours before I fill with coolant.

 

[71DodgeDemon340]

Whats everybody liking for valve cover gaskets, factory stamped steel valve covers. mine have been bone dry but going to pull them before the intake. The ones i have now appear to be rubber with locating tabs. I almost think that they are these. Builder assembled the engine, i had bought a engine gasket set but cant remember if the valve cover gaskets came with it or not

MAHLE Original VS39569R Mahle Original Valve Cover Gaskets | Summit Racing

 

[Rat Bastid]

If you are using paper intake gaskets then Edelbrock is correct. You use Gasgacinch on both sides of the gasket and on the head and intake faces. Then let the Gasgacinch dry and bolt it together.

Edelbrock didn’t develop that stuff. They just either bought it out or have their name on it. Paper gaskets is what Gasgacinch was developed for. And if you do it right, you can get the parts apart without a hammer and chisel.

I almost never use silicone on a gasket. Unless it’s for a nervous Nellie. It’s bad practice.

In fact, if I know I’m going to dyno an engine and I know (or even think it’s a possibility) that the intake manifold will be coming off I use grease, usually white grease because it’s cheap on both sides of the gasket and on the heads and intake. Bolt it down and go and you can take the intake off as many times as you want. And it won’t leak.

If you have to use silicone to seal up the corners of the manifold the chances are the manifold isn’t flat. They almost never are, even brand new.

If you are going to all the trouble to pull it off and fix it, I’d take it to a competent machine shop and have them take a clean up cut on both sides.