no exhaust manifold gasket??

[ttwinsupra]

So I wanted to wait till I removed my exhaust manifold to see what type of gasket I had before I ordered some, but when I removed the factory manifold I realized there was no gasket! it seems like it was just red RTV from the factory?? I did some google research and found some other forum posts saying the OEM manifold can use only RTV, and they even go so far as to say if you put a gasket on it without tuning the car it will actually run BAD?? this kinda shocked me, but I accepted it...

So I bought some good red RTV to make the gasket, but im looking online now for vids on how to do it right or info just to make sure its all good, but im not seeing ANYONE just use RTV... everyone I see uses at least a metal gasket and RTV...

Is it ok to just use RTV as a gasket alone?? like the factory?? is his even done? this seems so unnatural to me haha. also im only doing one side... one manifold, not both...

is this an old school thing?

 

[bracketchev1221]

Factory used no gasket when everything was new. Now, there is the risk that things have warped, maybe burnt from a leak etc. A gasket will not hurt anything But you can just use RTV. Just make sure you have time to let the car sit and cure before getting it hot. Then I find, starting it and heat cycling it a few times helps. Start it, let it run for a little and shut it off and let it cool and then run it longer next time etc.

 

[383_StealthRam]

What year, make model and engine are you asking about?

 

[ttwinsupra]

What year, make model and engine are you asking about?

its a 1987 el camino, with the cali emissions manifold. it originally had the 305 but from what I was told it was replaced with a factory GM 350 in the mid 1990s at a GM dealership, all legit. looks 100% factory all emissions stuff still there, factory air cleaner, factory exhaust and everything

 

[383_StealthRam]

I personally like the OEM style perforated graphite gaskets, but as other have said with cast iron to cast iron, provided the surfaces are flat high temp (RED) RTV should be ok to use. You'll know if there is a leak, but cast iron manifolds rarely do as compared to headers in my experience.