I'm about to replace my rusty exhaust manifolds with another set of stock manifolds that I had polished and jet coated. I've never done this before. My question is: Do I need to use any kind of gasket sealer with this? And if so,..what kind works best and where should I apply it. Thanks, Dave
exhaust gaskets. Unless you had the mounting surfaces of the new(?) manifolds resurfaced before coating them, I would recommend using gaskets between the manifolds and heads. You should be able to order them through any GOOD auto part store or engine supply company. Using just high temp silicon usually does not last very long and you will end up putting the gaskets on any way. You don't need the header style gaskets (usually thicker/softer) but you will want to recheck the bolts for the manifolds a couple of times after installation. Get the engine hot/let cool and recheck. I usually do this a few times to make sure the manifolds/headers stay tight and the gasket does not 'squeeze out'.
I have the gaskets,..but you say no need for any kind of extra sealer? I really appreciate the help. Thanks, Dave
Here is what Greg Gessler (Does Exhaust manifold porting, amount other things!) has posted on his website: Many manufactures did not use exhaust manifold gaskets originally, when new both the head and exhaust manifolds are surfaced flat. This method seals well and is very durable. After 35 years go by, both surfaces need to be resurfaced to get the manifolds to seal again. A less costly alternative is to use exhaust manifold gaskets, saving the cost of resurfacing both the head exhaust side and exhaust manifold surfaces. I always apply a thin coating of hi-temp RTV to both sides of the gasket prior to assembly.
