Couldn’t find anything searching on here, so was hoping someone would share their real world experiences on how the XKs Ceramic Exhaust Manifolds are holding up over time after having them on for a while:
They are not cheap, at close to $1100 with the gasket kit and shipping, so don’t want to make a mistake.
I hate going away from the glossy black porcelain look, but I haven’t seen any that can last from my searches on here. Most of the threads are pretty old, so maybe something new in glossy porcelain has come up recently?
That’s why the XKs cost so much. They claim to do that work.
“Ceramic-coated manifolds are first polished to yield a relatively smooth surface (a laborious process) and then coated inside and out.”
In another thread, you said it’s 40 hours of work. I don’t have the want or tools to do that work, so if I bought bare manifolds, sent them out to be prepped for 40 hours, and then sent them to be Jethotted, I wouldn’t be saving over the turnkey XKs.
Philip, my OE manifolds lost their porcelain decades ago. The remains of which was media blasted off. They’re pretty smooth and I think they would be fine (appearance wise) if ceramic coated. You and I may have different definitions of “fine”. Right now they have a fresh coat of Rustoleum bbq black and I think that looks “fine” too. So take my counsel with a grain of salt.
I did try to smooth the manifolds even more, and you are right. Time vs Money vs Skin lost in polishing. $1100 is not so bad.
I’d probably Jet-Hot silver mine for <$400. Obviously a guy who rattle cans his won’t anti up that much dough. All ceramic seems to dull a bit from use from what I’ve seen. Good luck with your decision.
I just got mine back from Jet-Hot and am happy with the outcome though I haven’t even started the engine after an extensive biannual maintenance routine. I have neither the skill or patience to come close to the smoothness represented by the picture of the XK’s manifolds but to me the “eye catching” areas are good enough.
We’ve been using the manifolds from SNG Barratt for years and they’re only $233 each or $142 bare with no ceramic if you want to try a different ceramic choice. The glass won’t last as long as the originals, but i’ll bet no one will give you a guarantee. What are the chances that all of our Jag suppliers each have a cast iron foundry making R & L manifolds for XK’s and E’s (they’re different) in a market where they will get a complaint in 5 or 10 years. Not likely. I think only 1 foundry somewhere makes them and all the suppliers buy those.
As an aside - I once bought a S1 E years ago that the owner had chromed a lot of stuff under the bonnet - very tacky. But, the manifolds were the most perfect black ceramic i’ve ever seen. When I looked closer, they were chromed too. The extreme heat had turned the chrome black (like on motorcycles). Only near the head it didn’t get hot enough to turn black.
XKs could be lying, but they claim they are having the manifolds cast from different metals:
“Rather than the original gray iron, these are superior ductile iron, a material known for its temperature resistance and dimensional stability”
And they do give a lifetime replacement guarantee:
“The coating is rated to 1300 degrees F and carries a lifetime guarantee against corrosion or failure of the adhesion to the manifold.”
I don’t mind about the price and I don’t really want a lifetime replacement guarantee, what I would really like to have is some real world feedback from people that have had them on the car for a while that gives me confidence if I buy them, they will last and I won’t have to be using that lifetime guarantee every 6 months.
I am surprised no one that has tried them has posted yet.
Its perhaps because in 50 odd years, in most instances, the only thing that has failed regarding original exhaust headers is the vitreous coating. I also suspect that the headers from XK are not a rapid seller; their Estimated Quantity Available is Zero, so it would be manufacture on as required basis. Then the original units can be Ceramic Coated for considerable less than the headers supplied by XK.
More sales hype than real world application where exhaust headers are concerned. The major areas of superiority of Ductile Iron over Gray Cast Iron is:
Modulus of Elasticity.
Strength to Weight Ratio
in all other areas, Gray Cast Iron wins hands down.
None of the above three don’t dramatically come into play when the headers are mounted and firmly secured to the head of the engine; more so when trying to dismount then from the engine and you’re a rough handler.
Years ago we would take the manifolds to a local stove works that would re-enamel antique stoves and parts. They told us the original enamel had a special blend of glass that without special analysis, they cannot duplicate. The cast iron and glass must expand and contract at near the same rate with the heating. Don’t run the engine too lean, and it will run cooler and last longer.
I think the ductile iron claim is for guys like me. Both my exhaust manifolds were significantly heat cracked. I recall looking those at the time. Don’t they also state the coating is not the deep black of the originals? And is composed of something different?