XK120s - 9:1 / 2 inch SUs / C type heads

XK
1

These are subjects that have come up from time to time on the list.

I am preparing an article about XK120s with 9:1 pistons from new. Just 29 such cars were made. Most went new to the USA. Is there anyone on this group that has such a car? A few certainly survive, but I would like to know more - especially if there is any documentation of a racing history, any original invoices, any replica plate on the car, if the original commission (ID) plate survives, and if the car had H8 (sandcast 2 inch carbs).

I would like to know of there is anyone on the list – or indeed elsewhere! – who has an original XK120 C Type head?

  • I do not mean Special Equipment heads. They are not C Type heads. Many people think they are.
  • Nor do I mean the (later) C Type heads that were fitted to XK140s.
    I mean the early C Type heads that were available as announced in Service Bulletin 95A, April 1953, said to be available on “an outright sale basis only” for the XK120. The casting number will be C7707 (as for the 140s), visible on the underside of the head on the exhaust side.

I look forward to hearing what you may have!

Kind regards, John Elmgreen Jaguar XK Motoring Historian

2

Hi John. My 1954 XK120 DHC has a Type C head on the rocker cover. Colour is red and numbers match from the Heritage Certificate. Need any other numbers?
John Manfield

3

Hi John M
Love to see some numbers from the head!
However the C Type badges on the cam covers are not correct for a 120, and of course can be added to any pair of cam covers regardless of what sort of head.
Look forward to hearing more.

  • John E
4

Hi John. I’ve been able to find two nos. One at the front F 3602-7 which matches the engine no. and one
at the back of the valley which looks like either AN 194 or ANI 94. You will probably know which it is. I do know that John Sawyer, Bob Jane’s mechanic at the time, did work on the head, cams, etc. in the 1960’s when Bruno Dabelstein had the car. Said he wanted more power!
Cheers, john Manfield

5

John M, thanks! No reason to think there was a C Type head here. Regards, John E

7

Ian
love to follow this up and see the photos in question. Where did Richard Colton race the car UK, USA or ?
can you send through chassis number engine number etc of your car
regards terry
tmcgrath@bigpond.com

9

A propos of nothing! I once went to a Ferrari V12 club afternoon tea at Richard Colton’s place with a friend who owned a 365GTC/4 at the time.

10

Hi John. You may have seen this already, but I just stumbled upon this article, which made me think of this post.

A nice story, but also, may lead to some more information for you.

1 Like
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Thanks, Joshua, much appreciated!

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what is the means, the provenance, to “know” the head or carbs were fitted from new…and what does “new” mean…does ne mean new from factory, new from dealer, by new owner upon receiving the new car or shortly thereafter? Any delivery papers, invoices, photos?
Nick

14

Here is the text of the SB95A dated April 1953.

SB95A C-Type head
SB95A C-Type head1175Ă—1483 215 KB

The “improved cylinder head, having revised porting” means this is a different head, not just modified from a standard head, aka “A” head.
The “outright sale basis” means “No, don’t send us your head for revised porting because we can’t do it to your head; you have to buy this head outright.”
I believe John was asking about early issues or editions of this head, without the letter C in the valley.

15

See my article in XK Gazette, January 2021 re the heads, 9:1, carbs etc.

1 Like
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John

I don’t subscribe to the XK Gazette but would be interested to read your article. Would you send me a copy?

Many thanks
Simon