346 exhaust manifold

[oldcarguy]

Hello,

Quick question...I want to pull the exhaust manifolds to blast and detail. When I replace them, do the bolts have to be torqued?
I would love to have them porcinalized, but the cost......Do you all think the Eastwood coating is good for this?
Thanks all

Don

[Steve Passmore]

Personally never seen any coating that works permanently, least not anything available in my country, and I have tried Hirsh and Eastwood paints.

[z3skybolt]

Don,

I recently had my 346 overhauled.  I did not have the manifolds redone.  The price is very high and a friend of mine, who has rebuilt many 346 engines told me that the porcelain will burn off, especially at the back where they join the crossover, within a couple thousand miles no matter what. 

If you do not intend to drive the car much...just show....then go for it. My car will be driven 2 or 3,000 miles each year.

Bob

[Virgil Perkins]

Don, torque is 25 min to 30 ft lbs max, per Cadillac LaSalle shop manual. Regarding your detailing your manifolds, not sure what you consider too costly but paint always looks like paint and at best you will get is a flat black after a few miles, which has to be touched up often. I had my 346 exhaust manifolds done at Independence Porcelain (Independence, MO) in 2015, have driven over 1,600 miles since, majority of which is interstate driving at 70 mph, and mine still look like new. No burn off anywhere.  I did try different paint applications, none of which lasted. Well worth the investment and made the engine look perfect.I think it ran around $461.00 which included shipping to Indy. Did outside only. My opinion for what it's worth.

[oldcarguy]

Steve, Bob and Virgil,

Thanks for your replies. Yes, I tried the Eastwood high temp [1400 degrees] in satin black and I'm sure my prep wasn't the best, it burned off right away! I would love the porcelain and the 461.00 doesn't sound that bad, I would be shipping from mid Tenn. The motor has about 1000 miles since rebuild and is really nice except for the manifolds...I showed once at a local show and won my class and I doubt I'll ever make a really big Caddy show. Guess the porcelain would just be for my personal satisfaction, the rest of the '41 '6219D' looks really nice. In retrospect, shoulda done the manifolds while the rebuild was going on!!

Thanks again,

Don

[z3skybolt]

Don,

Yes I regret not having my manifolds done during the rebuild as well.  Under the hood my car is as near perfect as the exterior.  My crossover pipe is excellent appearing and 2/3 of the manifold still looks nice. But the bare, burned metal at the firewall end sort of spoils all that other prettiness. However I was quoted a price of $1,500.00 to have them redone so I balked.

Too late I have learned that "someone" was taking advantage by quoting me $1,500.00. Would of had it done had it know it was more like $5 or $600.00.  Live and learn!

Naturally after finishing the engine and installing it... a poster on this site had two complete sets of manifolds his father had refinished years ago and never installed them.  The son was only asking $400.00 for each complete set. They were perfect. Should have bought them for future use.  But having spent a fortune on the engine rebuild it was time to shut down the outflow of cash.

Good luck,

bob

[Classic]

Has anyone had experience with powder coating exhaust manifolds?
Thanks.
Gene

[Fred Pennington 25635]

Powder coating won't work. They bake the powder at 400 degrees. The manifolds are capable of getting much hotter.
You can ceramic coat the manifolds in black. It will stay shinny but the coating is thin and shows the texture of the cast iron. It looks like paint it will not be as smooth as porcelain. The ceramic will probably be the longest lasting coating available but I found it wasn't much less cost then Independence Porcelain so I had them do mine.
Have not run the car yet so I am happy to read Virgil's post.

[las39]

Sent mine to UK, paid £180 for all three in 2013. Price was including blasting.
Excellent job and they still shine.

https://www.kingfisherenamelling.com/

[gary griffin]

A couple of years ago I had mine done by Prairie Porcelain, and it was about $400 as I recall.  They look great but not running yet so not sure how long they will look great!

[Bob Schuman]

The three manifold pieces for my 1940 LaSalle were done in 2009 by Independence Porcelain in Independence, MO. If memory is correct they cost about $400 and they looked beautiful. I drove the car several thousand miles before selling it in 2016, and the porcelain stayed almost as good as new. Turnaround time was about five weeks.
Bob Schuman

[Bob Schuman]

I forgot to mention that in 1975 Roesch Enamel in Belleville, IL porcelainized the manifolds for my 41 Cadillac, and after nearly 50,000 miles they still looked beautiful. That cost only $68 in 1975. Unfortunately, they quit doing that many years ago.