https://bringatrailer.com/listing/1955-jaguar-xk140-roadster-3/
Ooooo… that’s gunna reignite the “Are sand cast H8s original” debate!!!
Hi Paul:
As far as I know, the H8s are original to this car.
The starter carb in the accompanying parts collection is from a standard XK-140 FHC.
Evan
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Could be: I just know there was a flaming debate, a few months ago, about the sand cast H8s uses.
My parent’s Silverstone Jag had them as delivered, in 1952, as documented by photographs, but that is a very special circumstance.
Evan,
Would I be correct in assuming that you are the seller of this car?
If you zoom in on photos 25 and 26 you can see the raised casting number on the inlet manifold - C7462. Doesn’t that indicate the special 2 inch factory manifold for the H8 carbs?
Evan, is there a photo showing the coil bracket? I think those were made special for the H8s.
The mani has the same part number as my Type C, but the characters are cast into the rear of your piece, whereas the cast-in part number on my mani is under the thermo outlet. My carbs are the standard 1.75". So possibly the 2" version had the part number cast-in towards the rear?..or did the 2" version have a different part number?
Hi Paul:
Page 30 of the XK-140 parts manual: “Note: 2” carbs are for use with the C-type cylinder head
and are supplied to special order only."
Silverstone Jag sounds exotic - was it an XK-120 racer?
Lee:
The XK-140 parts manual lists two manifolds: C.7462 for 1-3/4-in carbs, and C.8479 for 2-in.
My manifold definitely has a 2-in inlet opening - no step where it meets the carb.
Hi Mike:
is there a photo showing the coil bracket? I think those were made special for the H8s.
I think I may be missing a coil bracket. But I’ll have look.
In photo 66/E-1 the rightmost coil has a bracket attached.
Is that what you’re referring to?
The H8s may be from back in the day, but my bet is they are not original to the car. It is difficult to see from the photos, but the intake manifold appears to have an Otter switch to activate an automatic choke on the front. The H8 setup had a manual choke and a blank plate where the Otter switch is. The H8s are also mounted incorrectly with the front and back carbs switched, but that is easily corrected. Nit picking aside, just having the new replacement parts is enviable. Looks like it is a doable project for someone and it is never bad to own a set of H8 carbs.
Evan,
From photos shown, it is impossible to say whether this H8 carburetter/Inlet manifold set up is factory original, or was an H6 set up originally, with after-market spare-part H8 carburetters purchased/obtained and fitted at some time afterwards.
The Inlet Manifold for instance. Yes, the SPC correctly advises that an H6 manifold is Jaguar Part Number C7462 and an original H8 manifold is C8479, but BOTH manifolds start using the 100% identical casting, which includes the more usual C7462 part number cast into the side, so superficially a C7462 manifold. But after the C7462 Manifold casting is received from one of two foundries used by Jaguar (and with visual differences in the casting from the different foundries) the casting enters the Jaguar machine-shop where it is fully machined, and assembled, to either the more common H6 C7462 specification, or the much scarcer H8 C8479 specification. Regardless how machined, it still visually shows the cast in C7462 number on the outside visible surface, in various locations that varies for both foundries, and indeed earlier and later batches from each foundry. There are actually five visually different castings regardless of whether machined up to be a C7462 or C8479. There are ways that I can tell whether an inlet manifold is an original finished C7462 or C8479 manifold, and indeed as usually happens when aftermarket H8 carburetters are fitted to a car originally fitted with H6 carburetters, whether the original C7462 manifold has been modified to accept H8 carburetters. Its a matter of looking at the detail of the machining/assembly differences between the two manifolds, and that detail is simply not visible in the provided photos.
There is similar clues regarding all other aspects of a factory original H8 setup, versus a factory original H6 setup, but again the detail required to identify whether yours is factory original or not is simply not visible in your photos. Indeed once you know all the detail variations, it is possible to install an H8 setup, identical to a factory original setup - but it is near impossible to get it 100% correct, but then I have also seen XK140s that were factory equipped with H8s, that over the past 60 years have had work done on them, or had parts changed/replaced, that now are not 100% factory correct either.
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As predicted…
Thanks for the deep info, Roger!
Thank you for that information, Roger.
Haven’t communicated with you in quite a few years.
Did you learn more about the the H8 choke knob location?
Cheers,
Evan
Thanks, Bob, for clarifying that and setting me straight on the reversed carbs.
From what you and Roger have indicated, the manifold may not be the original.
Why I believe the car originally may have had H8s is the choke knob shown in photo 74 in the BaT ad.
As discussed many years ago in this forum, there is a hole in the original dash that lines up with
the choke levers. Welcome advice on this: would that knob have come with an aftermarket H8 purchase?
First engine block heater I’ve seen.
A “doable project” boy I wished any or all the cars I have restored started like this!
I have the Jaguar XK engine block heater on a couple of my XK engined cars, but they are 4.2L engines, with the bushing and heater on the intake side of the block. They require an ultra rare bushing. While unusual, the Canadian market cars were equipped with them as a factory option. I suspect the American cars could have been ordered with them, but probably not really known about much.
My 1953 has a block heater exactly the same as the one shown on Evan’s car. I was not aware that this was a factory option for Canadian cars. The Heritage Certificate shows that my July-built car was initially shipped to a Toronto dealer and, as far as I know, has lived in Ontario all its life. Interestingly, even when using the car all year round after I first purchased it, I have never used the block heater nor have I needed to as the car always started fine in the depths of winter.
Chris.