Jaguar XKs

Fast Facts

• Best model: XK150S DHC
• Worst model: XK120 FHC
• Budget buy: XK140 FHC
• OK for unleaded?: No problem; inserts are already fitted
• Will it fit in the garage? (mm): L4267xW1549mm
• Spares situation: Very good, some repro stuff is poor though
• DIY ease?: Maintenance yes, restoration – not so much
• Club support: Excellent
• Appreciating asset?: Yes and rapidly
• Good buy or good-bye?: Not as sexy… but classier than an E-type?

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Suave E-type predecessor is just as stylish and capable in its own right. Strong performance with entertaining vintage-style handling mark the XK out as one of the most charismatic 1950’s sports cars and club and owner support couldn’t be better

Of all the Jaguars that he helped develop and hone, the sports XK was always one of Norman Dewis’ favourites. The late, great Browns Lane test driver rated the 150S as high as the E-type, which says a lot. So it’s no surprise that the car’s stock is rising in both value and desirability.

History

1948 the XK120 makes its début at the Earls Court Motor Show in October, with an all new 3442cc twin-cam straight-six – the now-legendary XK engine. The first XKs were bodied in expensive aluminium, plonked on a modified pre-war chassis; Jaguar having needed to save money when creating the production tooling.

1950 Jaguar didn’t expect the XK120 to create quite such a storm and taken aback by demand for its sports car, Lyons commits to creating tooling to make the car with steel panelling. As a result, after 242 have been made with aluminium panels, there’s a move to steel instead.

1951 Production of the Fixed-Head Coupé starts in July, and there’s also now a Special Equipment (SE) option which brings a high-lift camshaft, lightened flywheel, uprated valve springs, high-compression pistons, stiffer torsion bars and rear leaf springs, wire wheels and a twin exhaust system. The result is an increase in power from 160bhp to 180bhp. A heater (not a Jaguar strong point) is standard.

1953 In January, production of the Drophead Coupé begins. The new car gets winding windows and a heavily lined hood for decent refinement when cruising.

1954 The XK120 is superseded by the XK140, which is a more complete design featuring added cabin space, thicker bumpers and the adoption of rack-and-pinion steering. Indicators are now also fitted, something the XK120 did without.

The FHC is also six inches longer than before and the roof is an inch higher to provide space for a two-crush-two seating configuration. There’s also now 180bhp on tap, while the SE of 1955 gets 210bhp thanks to the fitment of a C-Type cylinder head. Overdrive is also now optional on cars fitted with a 3.54:1 or 4.09:1 diff ratio.

1957 Final fling sees XK150 replace the XK140, with 190bhp for the regular model and 250bhp in S form. The XK150 features a single-piece windscreen, disc brakes all round (with a servo), stiffer suspension, a broader grille and aluminium bonnet and boot lid.

1959 An engine capacity increase to 3781cc boosts power to 220bhp, while the uprated S model could now boast an E-type levelling 265bhp peak power output.

Driving and what the press thought

Comparing an E-type to the XK is an automotive equivalent to chalk and cheese because the latter feels far more vintage but that’s to the car’s benefit and is one of the things that makes this Jaguar utterly engaging and endearing even if the XK’s brakes, steering and ride feel like they are from another era, which they are. The XK120 in particular suffers the most here and why it’s more suited to the purist rather than the enthusiast who is most likely to find the XK140, with its better cockpit and rack and pinion steering, the better driver.

Much like with the E-type, evolution of the species meant a bigger, heavier bodyshell and a morphing from sports car to grand tourer. As a result, while the XK120 is a great point-to-point machine, the XK140 and XK150 are better suited to long-distance drives.

In period, the XK’s performance was nothing short of astounding. Autocar didn’t get to test the car until August 1950, by which point it was still having to tell onlookers that this was a regular production car and not a race machine. The magazine’s testers were bowled over by the available performance, stating “there is a temptation to draw from the motoring vocabulary every adjective in the superlative concerning the performance, and to call upon the devices of italics and even the capital letter!” Despite the fact that the XK120 was capable of over 120mph, it could be driven at 10mph in top gear, such is its tractability.

The magazine summed it up nicely, with: “Nothing like the XK120, and at its price, has been previously achieved – a car of tremendous performance and yet displaying the flexibility, and even the silkiness and smoothness of a mild-mannered saloon”.

Testing the revamped XK140, the weekly commented on its now near 50/50 weight distribution which “has eliminated the oversteer noticeable in the earlier XK120” and praised the new responsive steering and better cockpit although the added weight meant it was no quicker than the earlier XK120 despite being some 30bhp to the good.

When the magazine reviewed the XK150, in 1958, it found that its top speed was inferior to the XK120, but the testers were still bowled over by the Jag’s impressive performance, not least of all the tractability. To demonstrate the powertrain’s brilliance, the XK150 was launched from a standing start to 100mph in 36.4 seconds – using only top gear throughout. It was this flexibility which added to the driving experience; a lack of need to swap from one gear to another to maintain progress made piloting the XK150 a decidedly relaxed affair.

Motor got hold of the last of the line XK150S and said its performance compared favourably to the racing C-type it also tested at the same time, both covering 1/4 of a mile in 16.2 seconds. “If truth of the time-worn tag about the racing of today being the touring car of tomorrow ever needed proving, these two tests prove all the evidence necessary”. Summing up, it said, “All in all, thus XK150S Jaguar is a truly remarkable car which combines stupendous performance with surprising docility and good manners. To drive it is one of the more memorable experiences motoring has to offer (this was back in 1959 remember, ah the good old days-ed).

Improvements

If you’re aiming to use your XK a lot, you can make your life easier by installing a few upgrades. There are some XK purists out there, but specialists say, it’s not easy finding buyers for a standard car as just about any upgrade will add to a car’s value and make it easier to sell at the same time. Electronic ignition and a Kenlowe fan are extremely wise; while an alternator conversion is also a good move. Electric power steering is another modern touch that’s nice to have these days and while the £4000 cost of fitting it isn’t peanuts, it is good value.

The XK engine still has plenty of potential for more power with head and cam work although up to E-type spec (150S) may be ample for most but you can go much further – up to 300bhp. Best camshafts remain D-Type profile types after all these years and available from Guy Broad at £300 a pair. Period Jag tuning gear is available which may add to the XK’s value.

Guy Broad markets its Broadsport range of tuning parts that offers everything you need. As the XK is a popular racer still, the handling can be transformed with dampers and springs plus poly bushing but the company adds the secret of a good handling XK is “a loose rear end” enabling the car to handle in a neutral fashion or oversteer at will. Broad advises having the geometry set by a known XK expert as many are incorrectly set – perhaps even from new – as the transformation is said to be startling and perhaps one of the best ‘mods’ of them all!

By all means convert to discs but several XK experts recommend leaving the rear drums as they are rather than fit XK150S discs all round but Broad says a servo is best fitted to the front only as the rear drums have a tendency to lock-up quite easily otherwise. Five-Speed gearboxes are available although difficult to fit; the XJ6 transmission with overdrive is somewhat easier, we’re told.

Values and specialist view

You should always go for the best XK you can afford, as restoration costs can be incredibly steep, and even with values currently fairly high there’s a good chance you won’t get your money back for a while yet. As a result, if you’re on a budget you’ll almost certainly have to go for a coupé, as these are worth significantly less than an equivalent open-topped XK – perhaps 40 per cent or more reckons Ian Mills of Twyford Moor Classic Cars, arguably the UK’s leading XK specialist, who adds that values have levelled off over the past eight months.

The model most people opt for is the XK140 drophead, preferably with selected enhancements such as power steering, better brakes, alternator electrics and so on – showroom standard cars hold less sway, says Ian. You’d think that the first of the line, the XK120, would sell the best but Ian admits he struggles with them as they appeal only to the hardcore XK enthusiast. In contrast, the later cars are far better suited to touring, which is what most folks want.

How much is this Jag with the X factor? Twyford values a really nice XK140 DHC around £120,000 although truly top cats can nudge £200,000. In contrast, FHC are worth around £75,0000 – a big difference if you’re on a strict budget.

XK150S can be worth Aston DB money, more if it’s a drophead as less than 70 were made, and are tipped to rocket next year. Average-to-good XKs (of which there are many) are worth notably less although in Ian Mills’ experience buyers want only the nicest ones. He further adds that you can spot a DIY restoration easily enough thanks to incorrect shut lines and so on.

Still purring away?

XK engines can easily last 200,000 miles if they are properly maintained as these powerplants don’t like neglect. So check for evidence of regular oil changes and anti-freeze levels having been maintained, the latter to prevent overheating due to furred up waterways.

A worn XK engine gives the classic signs of needing a rebuild such as blue smoke from the exhaust and low oil pressure; there should be at least 40psi at 3000rpm – although the oil pressure gauges are notoriously unreliable. A known leaker is the crankshaft rear oil seal – an engine out job – but XK engines consume oil with relish one way or another. Listen for excessive timing chain noise but at the same time, over silent tappets.

On the prowl

While automatic transmission was available on 140/150, most are with a manual; a Moss unit that’s tough but hard going. Layshafts and roller bearings wear out but can be replaced albeit the bill can easily run to over £2500. Three-speed automatics are rarities but strong although tires out eventually, so check for tardiness from second to top shift.

The rear leaf springs commonly sag with age – but it’s possible to get them re-tempered, otherwise they cost over £120 (from DMG). There should be an inch between the top of the tyre and the wheelarch if okay.

At the front, check the usual culprits for wear and decay. Measure the ride height: if low at the front, then the torsion bar suspension can be reset. Wishbone wear means a new replacement, but slack in the XK120’s steering system can be successfully adjusted out by good XK specialists but there’s inherently more slop in the XK120’s steering as later cars rely on rack and pinion.

The drum brakes on the 120/140 models, if kept correctly adjusted (the self adjusters on later cars are unreliable), work reasonably well and can be okay even for mildly tuned cars. Wheel wobble on the XK120 is pretty common however and can be hard to eradicate. It’s best to drive a few to set a reliable datum or buy from a good XK specialist.

A dozen delightful years ends happily

Contributor Robert Couldwell owned his XK150 for 12 wonderful years almost four decades after wanting one once he passed his driving test at 17. “The idea was I would enjoy the car for a few years (taking it on tours to Monza, Nurburgring and Chimay-ed) and treat it like a pension, to be sold when necessary. I have certainly enjoyed it and it has proved a far better investment than some ISAs bought at the same time – doubling its value in ten years alone.

“Five years ago, the car was at K and N, the excellent Jaguar XK specialist for a service when the general manager of another specialist, Twyford Moors, happened to drop by and comment that perhaps this was the right time to sell my XK150 as it could fetch up to £100,000 if some issues were attended to.

“This got me thinking – perhaps this indeed was the time to sell when I wasn’t desperate and so not accept silly offers. Apart from anything else, I now found the Jaguar to be rather anti-social with just two seats and now fancied a genteel Alvis”.

After spending a bit of time and money getting the Jag as best as Robert could he was now in a bit of a quandary. “Having reached the car’s best condition ever, I couldn’t really use it as it’s impossible to maintain such a concours condition in regular use. I therefore would have to actively market the car and leave it under its cover in the garage.

“I placed the car on various web sites at £105,000 and I was initially impressed with the results, with seven or eight phone calls which resulted in two offers one of £85,000 and another from a guy in France of £80,000 which would have been over £90,000 except for the plunging Euro. Hoping for more, I carried on advertising but the process was becoming tedious so I got back to the guy who had previously offered £85,000 and said I would accept to which he replied that he could only offer £80,000 now. Hmmm…

“Time for Plan B: I took my XK to Twyford Moors, the company that I had purchased my XK from all those years ago and asked this expert to sell the car on my behalf. Less than three weeks later it was sold for £95,000, less commission and without all the pain and hassle!”.

Three Of A Kind

AC Ace, Acea and Greyhound

Fast and beautiful, the AC can’t keep up with the Jag in terms of outright pace, but it’s more delicate to drive and makes a brilliant individual choice. ACEs can top £250K but Greyhound is a bit of a bargain at 70 per cent less if you don’t mind mediocre performance from Ford Zephyr engine. Limited specialist support.

Aston Martin DB2/4 & MKIII

These Feltham Astons have well and truly taken off in terms of value and generally costlier to buy than the XK. They have a completely different character to the later, more popular DBs and are quite complex cars to repair and restore despite their age. A full buyer’s guide appeared in last month’s issue – back copies are still available.

Austin-Healey 100 & 3000

In this company the Big Healey is the budget option, although prices are fast catching up with the Jaguar and you can still easily spend £80K on a superb car – 100/6 are slightly cheaper. Don’t assume the sixcylinder car is automatically the one you must have; the 100 is lighter and better balanced. All feel more rustic than an XK.