Ceramic coated exhaust manifolds?

[Ed81DMC]

I’m replacing my exhaust manifold gaskets and am considering using ceramic coated manifolds from Delorean Auto Parts in Forney, TX (formerly Special T Auto). Had anyone tried them? I had some questions: 1) does the ceramic coating discolor, flake or peel? How badly? 2) Does the coating affect the gasket seal with the head? John Hervey the merchant says they don’t mill the manifolds. 3) How has your experience been with this merchant? 4) What kind of manifold mounting studs, washers and nuts do you all suggest? I’m considering all stainless but some merchants recommend a brass nut (assume for corrosion concerns)? 5) I was looking for stainless studs for the manifold to crossover pipe flange but someone said steel is stronger than stainless. Anyone concur or disagree or have a source? 6) who sells the direct replacement catalytic converter for Delorean? Does it come in stainless? I’m hoping to build or buy a stainless Cat and catback system for a price closer to $500 than $1000 and looking for proven suggestions.

[Bitsyncmaster]

The reason to use brass nuts is so they don't "gall" into stainless studs.

Yes normal steel is stronger than stainless but you don't have to torque the nuts that much.

[nullset]

I’m replacing my exhaust manifold gaskets and am considering using ceramic coated manifolds from Delorean Auto Parts in Forney, TX (formerly Special T Auto). Had anyone tried them? I had some questions: 1) does the ceramic coating discolor, flake or peel? How badly? 2) Does the coating affect the gasket seal with the head? John Hervey the merchant says they don’t mill the manifolds. 3) How has your experience been with this merchant? 4) What kind of manifold mounting studs, washers and nuts do you all suggest? I’m considering all stainless but some merchants recommend a brass nut (assume for corrosion concerns)? 5) I was looking for stainless studs for the manifold to crossover pipe flange but someone said steel is stronger than stainless. Anyone concur or disagree or have a source? 6) who sells the direct replacement catalytic converter for Delorean? Does it come in stainless? I’m hoping to build or buy a stainless Cat and catback system for a price closer to $500 than $1000 and looking for proven suggestions.

Personally, I will never again buy parts from that particular vendor. I've had too many failures and he's never honored promises to make it right.

[DMC-81]

Personally, I will never again buy parts from that particular vendor. I've had too many failures and he's never honored promises to make it right.

+1. for question #3). You can just do a search on this forum about this vendor. I got tired of wasting money returning substandard parts. Never again.

Question #4) I used DMC's mounting hardware, but I have heard P.J. Grady has Stainless versions if you prefer those.

Question #5) Correct. As Dave mentioned, carbon steel is stronger than stainless. (Although the torque values for the exhaust are low). You might look into the precautions of putting stainless studs into aluminum heads with heat. I believe a type of anti-seize coating is recommended. I applied it to my plated studs anyway.

Question #6) If DMC is sold out, I would check PJ Grady. The original cat is stainless (and the crossover pipe).

I haven't tried the ceramic coated manifolds. I had mine bead blasted, milled, and I painted them with POR-15 high heat manifold gray paint for around $100 total. After 13 months, they still look great. Here is a picture taken today:

http://dmctalk.org/attachment.php?attachmentid=56599&d=1527979762

[hippieman9]

In reference to ceramic coated headers. I have had a set of headers coated by Jet Hot and they look great for a while. After a while I have had to have them recoated. rust came through the coating. Jet Hot recoated them free of charge per their warranty. But If I had the option I would get an all Stainless exhaust. You can get the Stainless Exhaust studs from Delorean Go as well. I believe they even have the Brass nuts.