manifold questions...again!

[normanpitkin]

This is driving me nuts!! i have a new(ish)exhaust manifold for my 48 new yorker,if i get it ceramic coated (about $600,gulp) then will it fit/work properly?I have heard that as it is a three piece it needs to shrink to fit to seal so ,if it is ceramic coated will it still cool at the right rate to form a seal with the other parts? i am loathe to risk anything with this manifold ,took me nearly 2 years to find one!! On the other hand ,perhaps i should just sand blast it and heat paint it? What about the heat riser and choke ,will they still work if the manifold is ceramic coated? Sorry for all these questions !!!

[chopt50wgn]

normally when you take something to be coated, either powder or ceramic, you can tell them what needs to be covered. Or if you are sending it away, put tape on the parts that need be covered and then call the place to make sure they understand what you want.

I wouldn't heat paint it. I have never seen any heat paint stay on too much after it has been on the motor for any length of time. We get water pumps ceramic coated at my work and we have never had a fit problem after it was coated.

[Cpt.Fred]

i guess you can powder coat everything but the flanges' sealing surface.

i don't know about the heat riser because i don't know your setup,

but moving parts should be taken out or secured against the coating.

i blocked the threaded holes on my opel's manifold and everything went fine.

[Eneto-55]

Places that do powder coating will have the special tape & plugs necessary for covering or blocking areas you do not want painted. Take the part in & explain it to them in person. Nothing is worse than having the wrong type of tape, or plastic or rubber plugs melt all over the thing when it is being baked. (This from personal experience of working in a powder operation, and having people tape up stuff with skotch tape or electrical tape. Big mess if we missed some of it!)

[greg g]

Well he is talking about ceramic not powder coating. The processes may be similar, but the end result is a much thicker, heavier, and more heat resistant product. Minerals and binder vs plastic. I remember having seen some upper level cars, Packards, Duesenbergs, Pierce Arrows, Bugattis, Hispano Suiza, etc has having had procelin coated exhaust pieces. Porcelin being a much finer type of ceramic I guess. they sure looked nice, but other than appearence, is there an advantage to having coated exhaust pieces (perhaps reduced under hood temps) that is an issue against the expense?

I guess it works but does the coating expand and contract withthe piece as it goes through its heat cycle?

Didn't Pete A have his headers ceramic'd on his 50??? Check hit him as to his experience.

Used to be a company called Jet Hot that did headers and such for racers. Is their process similar to ceramics?

[claybill]

let me get this right.......?

you looked 2 years to find this manifold...

it is complicated w/ heat risers etc...

you want to get it c-coated for $600...

you have no idea whether it works or not......

sand blast it.

paint it black..

install...

DRIVE IT.!

bill

[Plymouthy Adams]

Bill, not everyone reads "Readers Digest", this is a segment of Masterpiece Theater where the plot thickens and drama unflolds and sorta oozes toward you..

[Eneto-55]

Greg, I was responding to the suggestion made previously to tape up the areas not to be painted - just wanted to clarify that this needs to be done with a special heat-resistant tape, same thing for plugs. I am not familiar with the process for ceramic, but I assume that it is baked after application, so the same caution applies, I would suppose.

Personally I am not overly impressed with powder coating. I took a job working in that field because I worked in the electro-plating field years ago, had heard of powder coating, and wanted to get some experience with it. The paint IS much harder than the common wet-coat paints, but it has some problems of its own. I Cad plated my manifolds, but have not yet fired it up, so I don't know yet how much it will discolor, or burn off. I don't think it should burn off, as we also commonly baked parts that were cad plated at 750 degrees (farenheit) for several hours.

Neto

Edited July 28, 2010 by Eneto-55
clarification

[Cpt.Fred]

sorry, i meant ceramic, of course. not powder.

anyway, tim, you're nasty!

[normanpitkin]

hmm ,all useful comments i suppose,I drive the car every weekend rain or shine (in all crappy weather in england),my main concern is that this new manifold will also crack sooner or later and I am thinking the ceramic coating will strengthen it.It would seem that due to the length of the manifold it is a design that is prone (even from new) to cracking due to different rates of heat expansion. The old manifold blows like billy oh,hence the new one ,also hence my desire to make it as long lasting as I can!

[greg g]

One consideration is not ot over tighten the fasteners. There is a lot of expansion and contraction going on there and restricting movement by over torquing is a contributor to cracking. The conical nuts and washers (they can be sourced from vintage powerwagon for one) are even more important on the 8 as those assemblies likely move more than on the 6.

You want it tight enough so there are no leaks, but no more. Especially critical are the connections between the maifolds at the heat riser. Those should be just snug enough to seal the gasket.

I don't think any coating will give your assembly a lot more strength, but it is certainly your choice.

[martybose]

hmm ,all useful comments i suppose,I drive the car every weekend rain or shine (in all crappy weather in england),my main concern is that this new manifold will also crack sooner or later and I am thinking the ceramic coating will strengthen it.It would seem that due to the length of the manifold it is a design that is prone (even from new) to cracking due to different rates of heat expansion. The old manifold blows like billy oh,hence the new one ,also hence my desire to make it as long lasting as I can!

If the cracking is caused by heat expansion as you say, ceramic coating will help PROVIDING that it is coated both inside and out. The inside coating will slow down and reduce the amount of heat that transfers from the exhaust gas to the manifold casting.

Marty, whose ceramic-coated cast iron headers stay really cool ......

[michael.warshaw]

i have ceramic coated (jet hot) exhaust manifolds on a high horsepower camaro pro street car. ceramic is for high heat only, good to about 2000 degrees, go for it look nice and the finish never bakes off.

[Andydodge]

Sounds like a case for some steel headers.......will go better and steel don't crack......well not as often as cast iron........o/k, will get back under my Oz rock.......andyd.

[normanpitkin]

I didn't want to go for steel tubular headers as it would have entailed changing the choke and the heat riser ,these fluid drive chryslers are soooo complicated I figured it was easier and better to keep it all original ,also my car is only 15500 miles from new so i kind of want to keep it stock.

[Andydodge]

Norman, fully understand the desire for originality, however would it be possible to fabricate a steel version of the cast iron header/manifold?........as an example there is a guy over here in Oz who sells "reproduction" exhaust manifolds to suit the late 50's early 60's Oz Mopars that used the 318 poly's. the originals have a tendency to crack and he makes these repros from 2"x2" square tube that have a header flange etc welded onto them, if you didn't know what the originals looked like then these are a good and more importantly a servicable option........might be worth having a look at.........what does the original manifold look like?..............andyd