Exhaust donut and manifold paint

[dadsgreentruck]

Hi everybody!

I have a small exhaust leak on the drivers side of my 307 (tick-tick-tick...etc). I think it's coming from the donut gasket. I removed the nuts and slid the flange back. Turned out I had to remove the manifold in order to gain enough play to get the exhaust pipe to drop down. Does the donut kind of "bake" on? How do you get the thing loose? It's the old asbestos type. It's stuck on the end of the pipe right now.

Also - as long as I have the rams-horn out, I thought I would have it sand blasted and re-finish it with Duplicolor 1200 degree ceramic containing paint. Will this hold up well or is there another type of finish I should use?

Tim

[Sammy]

The manifolds & the donut gaskets typically leak after a while. Usually the studs break off too so if they are not in great shape heat them up & replace them. The donut should pry out as far as paint never had much luck keeping 1200 stuff on them either for long periods of time.

[lowrollin70gmc]

POR 15 has a manifold paint that I used 3 years ago on freshly sandblasted manifolds and it still looks great no matter how hard I try and screw it up!

[wibilly]

i have also had exelent results with the high temp por on the headers on my vette 3 years and several thousand miles and still look great. i used the ceramic duplicolor crap on my truck last fall and it looked good til it set this winter and rusted badly both the headers and manifolds were blasted before being coated. por is the best i have found

[leddzepp]

Use POR 15....period.

[muscletrucks]

I went online and found the POR website. Is there a certain mix for exhaust manifolds or do I just but POR 12 Gray? What about any of the prep chemicals they sell, are they needed?

[lowrollin70gmc]

There is a specific manifold paint, I found it at a local parts store. You won't need very much, I barely dented the quart can I bought with two pairs of manifolds.

[Highsteel]

Originally Posted by lowrollin70gmc

There is a specific manifold paint, I found it at a local parts store. You won't need very much, I barely dented the quart can I bought with two pairs of manifolds.

This is the POR Manifold Grey that you are talking about?

[GMT900]

A lot of the restorer use this on cast iron.

http://www.calyxmanifold.com/

[zerwar]

Originally Posted by GMT900

A lot of the restorer use this on cast iron.

http://www.calyxmanifold.com/

I have used it on my manifolds from 1967 chrysler 440....that stuff works perfect!!! Highly recomended

[muscletrucks]

Thanks GMT

[mrein3]

I used Eastwoods brush on manifold paint on my manifolds 4 years ago. Still looks good today.

[Sport/Truck]

I’m curious to everyone who’s used Duplicolor and had failures, did you bake the manifolds at the proper temp like stated on the can? It says it optional for a more durable finish.
That’s what I did, I’ll have an opinion once I start running it.
s/t

[71 super]

The POR stuff is the best, the Eastwood does not compare. I used POR on set of BB manifolds and a set of cheapy headers and both still look great. The eastwood after blasting and prep did not hold up and started flacking off after a little while.

[ETsC10]

Originally Posted by dadsgreentruck

Hi everybody!

I have a small exhaust leak on the drivers side of my 307 (tick-tick-tick...etc). I think it's coming from the donut gasket. I removed the nuts and slid the flange back. Turned out I had to remove the manifold in order to gain enough play to get the exhaust pipe to drop down. Does the donut kind of "bake" on? How do you get the thing loose? It's the old asbestos type. It's stuck on the end of the pipe right now.
Tim

Concerning your manifold gasket, yes, the bugger should chip right off. I've always used solid steel donuts and never had a problem but I don't know if the pipe-side is shaped different to use the steel style.
If you can, replace your studs and check the manifold to block area for flatness. Do not use a gasket between the manifold and block....clean both surfaces and bolt up tight. Use lock washers.
...just my .002 worth...