Can silicone gasket sealant be used between the intake manifold and head along with the gasket?

I have a rather old intake manifold(DOVE). Before I removed it, there was no external oil leaking. But as I am cleaning it up to put back togther the surfaces are not great, esp. near the exhaust warm up in the center of the head and intake manifold. Looks like oil/carbon was forming on the surface and inside of the center intake ports. Cleans up very smooth but I do not want any leaks.( Leaks drive me cazy, I hate em )

I believe I can use RTV on the end of the intake manifold where the rubber seals are provided in the felpro pak.

The gasket before was gaskets on both sides of the intake manifold with an aluminum(?) bowl piece connecting the two gaskets. I am just using two individual gaskets this time.

Thanks
Greg

 

absolutly not,youwill ruin the seal of the intake gaskets.You can however put some rtv in the corners of the end gaskets where the head meets the block.

 

thx Mush,

This is my 1st rebuild of a Big block.

I will add some more pic soon.

Greg

 

Why are you using the two individual gaskets instead of the design which covers the valley? With the exhaust crossover, you need the valley part to keep from cooking oil on the underside of the intake.

 

I have to beg to differ on the silicone in use with the gaskets. It mainly depends on what material the heads are and the type of RTV your using. Any RTV that smells like vinegar is highly corrosive. Hence it is a common no no for aluminum heads. Unless you tear it down every so often. You can use Silicone around the water jackets and the intake ports as long as you are not gobbing it on there. A thin film is the prefered choice. Just be sure to keep from getting too close to the edge, it'll spread out more as the intake is TQ'd.

 

I agree with Mark. If a slight amount of RTV isn't used, I've found it very difficult to get a full seal. Edelbrock's website has an excellent guide on prepping the intake manifold for installation. While their instructions are for aftermarket aluminum manifolds, most of the basics apply to any install. Especially about using RTV instead of the end gaskets.

 

I have found that permatex has a red gasket liquid called High Tack. It seams to work really good. It is gas permuable(check my spelling later) and really helps hold the gasket in place. Be prepared though on a tear down to spend some extra time removing gasket material!

 

georgedavila and airharley are absolutely right. A thin coat of RTV around the ports and passages is the ticket for absolute sealing. Along with that, ever since I quit using the rubber or cork end gaskets in favor of a nice thick bead of RTV and the manifold ends, I've never had a vacuum, oil or coolant leak.

Also, be sure and get that valley pan in there.

 

Thanks guys,

ludis, the reason I was not using the valley covering gasket: Well, the gasket pack I got for the rebuild gave only the individual sides and so I would have to buy additional gasket, and on another post I did, others had said it wasn't necessary or was not really helpful and I had thought that originally the engine came with just individual single gasket for each side. A negitive is with the valley in when the engine cools down I think condensation seems to form and you get rust on the bottom of the cast iron intake.

On the the other side of it, it seems the covering of the valley would, like you said, keep heat(cooking oil) away from the intake manifold. Heat is something I am trying to avoid with 9.5:1 CR.

I would appreciate more comment on the above.

Also, on RTV, I usually use Permatex Ultra Black Hi-temp RTV Silicone gasket maker. But this is not rated for continous contact with gas. I usally only use it around water passages. Would that red gasket liquid called High Tack from Permatex be ok on the whole intake, including the Hi temp area in the center for the exhast gas passage to the intake manafold ports, and the water passages on the front end, and a thick bead on the ends with or instead of, the rubber end gaskets? Or maybe just the Hi Tack around the intake ports and Black Hi Temp around the middle warming exhaust intake ports, water ways, and the end joints.

How would you all do it?

Thanks for the help, just don't want to have to do it twice.

Greg