430 exhaust manifold question

[60s GM Fan]

 

While my engine is in the machine shop I figured I'd clean my exhaust manifolds up before they reinstall the engine.  Were the factory manifolds bare metal or were they painted/coated?  I'd like to ensure they're done right before they go back on my motor.

Edited June 24, 2021 by 68RivPearle (see edit history)

[Pat Curran]

I assume you mean exhaust manifolds?  If so, they were bare metal.  

[60s GM Fan]

Yes and thank you.

[RivNut]

To keep them looking fresh, coat them with

 

 

Caylx manifold dressing.

 

[60s GM Fan]

Awesome never heard of that before!

[telriv]

AND while they are off get the mating surfaces machined FLAT at a machine shop. Better to do it now than when the engine is back in the vehicle & have an exhaust leak as the manifolds attach to the heads metal-metal, NO GASKETS!!!!   And tell the builders that also as in the engine gasket kits they ALL include exhaust manifold gaskets & since there are in the kit most/all figure if they are in the kit they should be installed which is NOT TRUE as Buik mounted them metal-metal.

Reason being heat disapation.

 

Tom T.

[60s GM Fan]

You learn something new every day!  Thanks for the advice.

 

[KRmanr]

What happens when Exhaust Manifold Gaskets are used on BBB's? 

They're less likely to leak.

[KRmanr]

I like them painted. Here's a great looking example.

[telriv]

NOT likely.

[JZRIV]

On 6/24/2021 at 10:03 PM, KRmanr said:

What happens when Exhaust Manifold Gaskets are used on BBB's? 

They're less likely to leak.

Maybe at first but they will leak.  When using gaskets there is a greater chance to crack a manifold as gaskets do compress and if not very carefully torqued can put stress on the somewhat fragile casting. Truing the mating surfaces and not using gaskets is the preferred method. I did a tech article on this in Riview a few years ago.