84 FB

I've searched and researched all the various options for installing the stock 12a 84 manifold, last October and again last night.

My conclusion is to go with the FSM procedure and use the OEM gasket and O-rings.

A little hylomar on the O-rings to keep them from popping out of place, but undecided on coating the gasket.

I've heard of putting a thin layer of silicon on both sides of the gasket. I have black, red, blue and grey. Which one is best for this application?


History: Last October the engine failed. I first thought it was the intake manifold O-rings and replaced them and the gasket, but no joy. (Upon the rebuild I discovered other issues, one was the lower back dowel pin was broken.) When mating the manifold to the engine I noted the rotor housings were not flush with the irons. After the rebuild the manifold now sits flush from the rear iron to the front iron with no visible gaps as before. When I break something I tend to do a good job of it.

 

I use a very slight film of silicon on the gasket. This is not so much for sealing as it is for getting the gasket off easier if need be.

 

i'd just use a thin coat of black or grey silicon. in theory it can go on dry, but the silicon keeps it from mummifying to the block. i put the silicon on thin enough that you can see the green color of the gasket still.

 

Thanks guys. Works for me.

I am amazed as to how fast it goes back together compared to taking it apart & the prep time.

 

I use black or grey and make sure you only put a thin coat on