Cost !

 

In my case anything over $1,000 USD and I would really have a hard time justifying it. $800 seems pretty reasonable just off the top of my head.

 

$800 would be a sweet spot for me too. That is what I paid for a set of custom headers for my Impala SS.

 

Maybe I'm being unrealistic, but for me anything much over $500 starts to be hard to justify.

But under $1000 definitely, and that $800ish range is probably in the realm of possibility.

And I'll probably need one sooner than later, as I'm relatively certain I can hear a slight exhaust leak now. I'm not certain it is the header, but....

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Hmm..... US$800 is not even enough to buy factory exhaust manifolds made of cast iron (currently priced at GBP550 for a pair) from Jaguar Heritage (Classicjaguarparts.com); shipment would be extra, plus labour of your workshop. Britishparts.com.uk lists them cheaper, at GBP275 for a pair, again shipment extra, but I am not sure why Britishparts can sell them so much lower, and it is uncertain about quality and availability. The harsh fact is exhaust manifolds in cast iron will crack (short length design leads to lack of room for expansion and the turning angle is adding strain to the pipes), but if folks are not planning to keep the car long then the factory headers would be a logical choice option, and a lesser evil of the SS option.

I am wondering if it would make better sense fabricating exhaust manifolds in cast iron in better design so the lower cost justifies more purchases, and people would be more willing to replace them again when they crack. This is normal customer behaviour.

 

I paid $1000 CDN for two factory exhaust manifold, though the Canuck buck was stronger last year. Even at a 15% or so premium right now, $1000 USD would be very reasonable for actual headers, especially stainless ones that won't crack as fast as factory.

 

X300 exhaust manifolds are GBP140 a piece from britishparts.co.uk and a couple of other places. That's under $500 with shipping to the US. I suspect that they are OEM made by a vendor who has all the necessary tooling that was used originally when these were made for Jaguar . Otherwise it would be very difficult for them to make any money at this price. I suspect it's the same vendor that made them for Jaguar, but I have no proof of that.

I had my cracked manifolds welded by a shop that does a lot of cast iron welding. They TIG welded them using a special rod for cast iron. Welding cast iron is tricky, but it can be done if you know what you are doing. I own a mig welder, and I am pretty handy with it. I did not even consider doing it myself. To paraphrase Dirty Harry "a man has got to know his limitations"

 

Its difficult to argue with £140 each from Britparts. At that price you can consider them a consumable items. I could never get fabricated parts made for anything approaching this price, even as a small batch.

 

Very true. Although if around $500-800, I could convince myself that around $300 more would be feasible for something that would last and in theory perform better

Of course it is all academic at this point as no one is offering a set of SS headers in North America for $800 AFAIK

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Certainly, GBP280 a pair is a much more affordable fix, even for one to two years. Is availability an issue, as this does not explain why there are so many people driving with leaking headers, buying used ones (they sell quickly on eBay), and welding broken ones? I heard that welded ones will not last long as the headers will break near the welding lines.

 

It's a straight 6 so I'm pretty sure it would just be one.

 

I have a 40,000 mile, southern California car so hopefully my exhaust manifold will last the life of the car. Knock on everything....

My interest in a header would be to free up a few horsepower and get a nice growl from the engine. Straight 6's sound beautiful with a properly tuned exhaust.

 

It is actually a pair, each one covers 3 of the 6.

 

This thread has languished for a while...

Every salvage exhaust manifold I've seen is cracked, and I suspect mine is too from the mild "chuffing" sound I sometimes can hear under the hood, especially when cold.

As mentioned, new OEM manifolds are horridly expensive, and I bet will just crack again.

So the interest still exists on my part at some point in the future possibly.

I wonder, for those that have built these overseas, do you have a CAD drawing you could license/sell? That might make it easier and cheaper for someone to have it fabricated here in the US.

I wonder too what it would cost and how long it would take to just drop off my car at a good exhaust shop and have them make a set... even in regular steel then just have them ceramic coated.... hrmm

Headers and the upper cat removal might be a good combo project (if the O2 sensor issue/question is resolved):

https://www.jaguarforums.com/forum/x...l-4-0l-128820/



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I started this thread but as folks can see there isn't much interest in a costly option if and when the factory solution is still sort of affordable and available. The other problem is many X300 owners are still undecided whether to invest further in the car. This is sort of late to consider a group solution, as XJR6 fanatics are but a very small number. I still have the full set of stainless steel headers, manifolds and downpipes with me (they were custom-made in the UK), and I have not yet installed them on my ill-fated XJR6 which has fallen into deep coma. I shall see if I have any luck in reviving the project. Nevertheless, a buddy down south may have the specs for a total solution, and it might be worthwhile pursuing from there.

 

I can offer a pair of dxf computer files. These can be used to programme machines that can cut sheets of metal with either lasers or high pressure water. The files contain the profiles of the front and rear exhaust manifold flanges. I would recommend that these flanges are cut from 8mm thick 304 grade stainless steel. These flanges can then form the starting point of fabricated replacement manifolds or in facts complete 6 into 2 tuned length manifold and downpipe combinations. Please contact me directly by email, if you want more details. andystodart@Metronet.co.uk


As posted above, whilst the factory original parts are still available I do not think that there is sufficient demand for me to justify manufacturing fabricated parts, as they will be much more expensive than cast parts.