Resto: J54-469

1954 JAGUAR XK-120 OTS

A CLASSIC SHOWCASE CLIENT RESTORATION

This one owner since new, CA black plate XK-120 was built May 6, 1954. It was a special order from Charles Hornburg distributor in CA, used lovingly, and driven with great pride. One of only ten XK-120 FHC with a 9.1 compression engine and sand cast carbs, it has been a California car its entire life, and garage kept. It includes the old entry forms from the 1955 and 1956 entry at Bonneville (In 1957 it has an entry letter, but the car was not able to attend) and some letters the prior owner wrote back in the 60's detailing the history of the car as well as a Heritage Certificate verifying its authenticity. It is a Bonneville record holder. Mr. Woods, the previous owner, was an interesting man who had interesting times with this fascinating Jaguar.

Prior to beginning its Show-level restoration, it had some modifications made to it to make it a more reliable driver such as:

• A true dual exhaust with a cross over and glass packs have been fitted to the car

• The rear end had been converted to tube shocks

• Traction bars were added to the rear suspension.

• Fit with a XK140-150 voltage regulator and cooling fan

• Perfect Circle 98 oil rings on pistons

• Perfect Circle Teflon valve guide seals

• Addition Frantz oil filter assembly
• Perry water filter assembly
• Marvel mystery inverse top cylinder oiler
• Ed Iskenerian ground cams, .404 lift
• XK-150 water pump
• Factory installed sand cast carburetors
• The dual 6-volt batteries have been converted to a single 12 Volt
• It had the head milled for extra compression

S681469 is a significant car in Jaguar’s history; one of ten ex-factory delivered 9:1 CR LHD FHC XK120s. We are aware of only two others that have survived (679841 & S681452) but this Jaguar has competition extras fitted which makes it significant.

The debate rages if a “C Type” engine was ever fitted ex-factory to an XK120. S681469 may offer rare evidence there was. Over the last few years one historian has compiled (from sightings, photographs of parts and factory literature) enough detailed information about C and D Type cylinder heads, fitted to factory competition and production cars, to be able to identify a genuine fitment. S681469 offers a very rare opportunity to prove a “C Type” head was fitted when the car was originally dispatched, on 14th May 1954.

This car is the only known XK120 to be -

dispatched new from the factory with 2” carburetors. There may be other cars, somewhere, but the factory records do not contain this level of information. From a historical standpoint it would be significant to establish if any XK120s were built with “C Type” competition parts when dispatched from the factory, rather than aftermarket (which has been established with a couple of late RHD fixed head coupes).

The main identifier are the code numbers stamped on the top of the inlet flange of each carburetor which gives the possibility the cylinder head is a “C Type” specification. The numbers stamped in the plug valley will partly confirm; the engine number (F2935-9S) at the front and the number stamped on the small plinth at the rear do as well.

2” H8 Sand cast carburetors: The numbers stamped on the inlet flanges are date codes, stamped by SU when fully assembled in their factory. These codes are not unique to H8’s or Jaguar and are seen on all SU carburetors of all sizes fitted to many car marques in this period. The same codes are also stamped on SU fuel pumps. The letter is the year and the number the month; so, the stamping on these two carburetors K9, denote September 1953. The date code has been deduced from references in SU factory literature and also many, many sightings of carburetors in original cars, where the car’s build date is known. The standard carburetors (e.g. H6) generally pre-date the car build by about three months. The carburetors were manufactured, assembled and stamped by SU, dispatched to the car companies, where they sat in parts bins until fitted to an engine. The codes stamped on a pair of carburetors are not always identical.

The other indicator of the date of a carburetor’s manufacture is that in 1955 SU Carburetors were amalgamated into Austin Motors and the part codes for all SU carburetors changed. The part code cast in the early bodied H8’s is 5001 and then later AUC6000. The two casting differ a little but not in body’s functionality. So H8’s originally fitted to XK120s and C-Type race cars will have 5001 bodies and XK140s AUC600. A later bodied carburetor fitted to an XK120 indicates aftermarket fitment. We believe these H8’s (made September 1953) were fitted to S681469 when the car was originally dispatched from the factory in May 1954.

C-Type cylinder head: F2935-9S head was machined to C-Type spec by the factory and most likely fit to the car when dispatched in May 1954. The part number C7707 cast/stamped half way along the exhaust side denotes C-Type spec. Note the last number, ‘7’, is stamped over a ground off ‘0’. Later C-Type heads fitted to Xk140MC (painted red, with C cast in the plug well) were an evolutionary casting, C7707. Interestingly, both C7700 & C7707 heads were the core casting for D-Type specification; the head machined, and the original part number ground off and stamped C7896. We have seen examples of both C7700 & C7707 core heads machined to D-Type specification. The C7700 head postdates the C-Type racing cars (XKC001-053) which were machined standard A-Type heads (part C6733). It is difficult to confirm the date the first C7700 head was cast, but evidence suggests early 1954. This head, F2935-9S is from May 1954 and one other F prefix 9S head (not the car or engine, just the head) we believe was fitted to an XK20 built in late April 1954. Not all 9:1 CR XK120s are C-Type spec; F2698-9S, fitted in S681452, April 1954 is a standard A-Type head. We understand there were 32 XK120 fitted ex-factory with 9:1 CR heads; We have only heard of the mentioned three. The number cast on the underside of the head (RH139) at the front is a sequential number cast by the foundry, West Yorkshire Foundries, in Leeds (WYF logo next to the number). The RH prefix is characteristic of all C & D-Type heads.