Exhaust Manifold Construction

another try

here's a peek at the sterling Jet-Hot coating of my european "Y" pipe, non-cat. the front caT is empty. Notice I cleaned and refreshed the chassis-to-engine Ground Strap, (look to the left), including the two mounting bolts, the bolt-hole threads, and the body and engine contact areas with a brass brush mounted in a drill for speed, the electronics became alive! Grrrround!

you may have been looking at coated manifolds, since I don't think anyone manufactures stamped-steel manifolds. why bother replacing the cat? just get a european-version non-cat downpipe, or pry open the cat and remove the bag of toxic charcoal inside, clean the inside well, then reweld it and pressure test-it. the car will pass emissions testing without the caT anyway, well at least the fuel-injected cars do. there must be an experienced Jaguar technician in your area that you can consult with about the red-hot manifold. if the manifold itself is the problem, you can get used ones at eBay, new gaskets are cheap, but the labor is another story, you might have to remove the front manifold to get to the rear one, which I would do anyway to check both.

While they are outside, have them coated with Jet-Hot Coatings' Black Sterling for a reduction in exhaust temps and better exhaust flow. I had all the exhaust pipes in my XJ-6 coated in bright sterling, (looks like chrome but not exactly), and the difference in temps is outstanding, the pipes are also coated inside. I no longer have a hot spot under the driver's feet. The Jet-Hot coating formula is a blend of silver and ceramic powders, it was not expensive. They can take your old pipes and make them like new.

What I would do is to substitute the manifold in question with another one, and see what happens before messing with the carbs or anything else.

What is the timing on this engine at idle? Disconnect vacuum? It idles at about 800 RPM after warmed up. Any way to make minor adjustments to the mixture (Zeniths)? Haven't found anyone willing to work on this car. I can do a lot myself. I am near BASSETT's in Rhode Island, a well known shop. Not sure if my car's classic enough for them :-) Winter's coming, maybe I'll just yank the carbs and see what I can see. Does the hose to the ear balancing method work with these carbs? Are UNISYNs still available and are they usefull on this engine?

I am betting I was looking at coated manifolds. I am pretty worried about the redhotness. The rear manifold seems to be the hot one. Could one of the carbs be running very lean? I pulled the plugs and they look pretty much OK, not as if they were running very hot. All 6 plugs were about the same. I was thinking of replacing the CAT just to be sure. Hard to come by, but I found one for about 200 US. I don't use the car much and am pretty scared of the old thing. Most of my "toy" cars have been 50's and 60's, easy to fix. This is my first Jaguar but my 5th English car. Sure don't want to ruin it since it's really a sweet looking and driving machine.

The red hot manifold is a problem which will destroy the manifold. It is most likely caused by retarded timing or a very weak mixture, have it taken care of. Jaguar affectionado and etc.

The red hot manifold is a problem which will destroy the manifold. It is most likely caused by retarded timing or a very weak mixture, have it taken care of. Jaguar affectionado and etc.

The red hot manifold is a problem which will destroy the manifold. It is most likely caused by retarded timing or a very weak mixture, have it taken care of. Jaguar affectionado and etc.

never heard of stamped steel manifolds, even my 1965 3.8 S has cast iron manifolds that never get red hot, and that engine runs hot!. My '84 XJ-6 4.2 engine has similar iron manifolds, in the S type they are covered by a black ceramic coating. So, you should investigate this before you start that engine again, manifolds should not get red hot, no way.