Jaguar 420 and Daimler Sovereign (1966–1969) — BrandWiki

Jaguar 420 and Daimler Sovereign (1966–1969)

Overview

manufacturer	Jaguar Cars
production	Jaguar 420: 1966–1968 (10,236 built) Daimler Sovereign: 1966–1969 (5,824 built)
related	Jaguar Mark 2 Jaguar Mark X
predecessor	Jaguar S-Type
successor	Jaguar XJ6
class	Sports saloon
body style	4-door notchback saloon
layout	FR layout
engine	4.2 L XK I6
transmission	4-speed manual (Jaguar only); 4-speed manual/overdrive; or 3-speed automatic options available
length	4762 mm
width	1702 mm
height	1429 mm
weight	1676 kg
wheelbase	2727 mm
sp	uk
assembly	United Kingdom: Coventry

The Jaguar 420 (pronounced "four-twenty") and its Daimler Sovereign equivalent were introduced at the October 1966 London Motor Show and produced for two years as the ultimate expression of a series of "compact sporting saloons" offered by Jaguar throughout that decade, all of which shared the same wheelbase. Developed from the Jaguar S-Type, the 420 cost around £200 more than that model and effectively ended buyer interest in it, although the S-Type continued to be sold alongside the 420/Sovereign until both were supplanted by the Jaguar XJ6 late in 1968.[1]

Pedigree

The 420/Sovereign traces its origins back to the Jaguar Mark 2, which was introduced in 1959 and sold through most of the 1960s. The Mark 2 had a live rear axle and was powered by the XK six-cylinder engine first used in the Jaguar XK120 of 1948. The Mark 2 was available in 2.4, 3.4 and 3.8-litre engine capacities.

Design

Styling

The starting point for design of the 420/Sovereign was the Jaguar S-Type, which had been in production since 1963 but whose styling had never met with universal acceptance.

In styling terms, the 420/Sovereign was essentially an S-Type with that car's curvaceous nose made much more linear, the better to match its rear styling (which was not altered). Contouring around its four lamps was relatively subtle, with small peaks over each, and its flat frontage sloped forward slightly. The square grille with central divider matched that of the 420G, (which was the new name given to the Mark X at the time of the 420/Sovereign's release). The low-set fog lamps of the Mark 2 and S-Type were replaced by a pair of inner headlamps at the same level as the main headlamps. The inner lamps were lit on main beam only.[3] Dummy horn grilles were added below each inner headlamp to break up what would otherwise have been a large expanse of flat metal on either side of the radiator grille. The tops of the front wheel arches were flattened to match the squarer lines of the nose. The slimline bumpers dispensed with the centre dip which had characterised the bumpers of the Mark 2 and S-Type. All this was done to improve the car's aesthetic balance compared with the S-Type and to create a family resemblance to the Mark X/420G, changes which Sir William could not afford (in either time or money) when the S-Type was designed. No attempt was made to give the 420/Sovereign the same front-hinged bonnet as the Mark X/420G and it retained a rear-hinged bonnet of similar dimensions to those of the S-Type and Mark 2.

Interior

Changes to the S-Type's interior to create the 420/Sovereign were driven mainly by safety considerations, with the wood cappings on the doors and dashboard replaced with padded Rexine and a wooden garnish rail on the tops of the door linings. The clock was relocated from the tachometer to the centre of the dashboard top rail, where it was powered by its own battery. The S-Type's pull out map tray below the central instrument panel was not carried over although the 420 retained the same central console and under-dash parcel tray. The seats of the 420 were of slightly different proportions from the S-Type, although they appeared very similar.

Engine

The 4.2-litre XK engine of the 420/Sovereign was fitted with the straight port cylinder head and 3/8-inch lift cams. Compression ratios of 7:1, 8:1 and 9:1 could be specified according to local fuel quality, the difference being obtained by varying the crown design of the pistons.[4] The engine was fed by just two carburettors and developed a claimed 245 bhp gross at 5,500 rpm,[5] which was 20 bhp less than the triple-carburettor version in the 420G and E-Type. The maximum torque of the engine at 283 lbft was virtually the same as that of the triple-carburettor version yet was achieved at 3,750 rpm rather than 4,000 rpm.

The factory-quoted horsepower rating of 245 bhp was measured using the SAE (gross) system current in the USA at the time the 420/Sovereign was sold there. The SAE (gross) system excluded many accessory drives and often used non-standard induction and exhaust systems and so was replaced by the more accurate SAE (net) system in 1972, long after the 420/Sovereign had gone out of production. Reference[6] states that the DIN horsepower rating of the 1977 USA specification 4.2-litre Series II XJ6 was equivalent to 180 bhp. The DIN system yields horsepower ratings which, for most technical purposes, are the same as those that would be obtained using the SAE (net) system. However, the 1977 test would have included power-sapping emissions equipment not present on the 420/Sovereign. Therefore, the SAE (net) power rating of the 420/Sovereign must have lain somewhere between 180 bhp and 245 bhp.

Mechanical

A novel mechanical feature that the 420/Sovereign shared with the 420G was Marles Varamatic power steering,[4] which was offered as an option on the 420 but was standard on the Sovereign. Built by Adwest Engineering Co Ltd of Reading, England, it was a "cam and roller" system in which the non-constant pitch of the cam resulted in a variable steering ratio, with the lowest gearing being at the straight ahead, rising rapidly to either lock. The rise in gearing (equivalent to a drop in ratio from 21.6:1 to 13:1) occurred almost entirely within the first half turn of the steering wheel from the straight-ahead position. The effect was to give very light and relaxed steering at the straight ahead, with quick reaction when cornering. There was no adjustment in the behaviour of the steering in reaction to road speed. A very few of the last S-Types were similarly equipped.

Other mechanical refinements the 420/Sovereign had over the S-Type included:

replacement of the Borg Warner Type 35 automatic transmission with the stronger Model 8
a more efficient cross-flow radiator in place of the S-Type's smaller vertical flow type
a dual-line hydraulic braking system replacing the S-Type's single line system
twin 2-inch HD8 SU carburettors (cf. the S-Type's twin 1.75-inch HD6 SUs)

Daimler

Whereas the Daimler 2½-litre V8 released in 1962 differed from the Jaguar Mark 2 in having a genuine Daimler engine, only the Sovereign's badging and aspects of interior trim differentiated it from the 420.

The market perception of the two marques Daimler and Jaguar, which the material differences between them sought to foster, was that the Daimler represented luxury motoring for the discerning and more mature gentleman whereas the Jaguar was a sporting saloon aimed at a somewhat younger clientele. In the Daimler model range, the Sovereign filled a gap between the 2½-litre V8 and the larger and more conservatively styled 4½-litre Majestic Major. Prices in the UK of the basic 420 and Sovereign, as quoted in the Motor magazine of October 1966 were:

Manual o/d – Jaguar £1615, Daimler £1724 Automatic – Jaguar £1678, Daimler £1787

In return for the ≈6.5 % difference in price, the Daimler purchaser obtained only a few substantive advantages but would have considered the cachet of the Daimler badge to be well worth the extra money; indeed the Daimler name attracted buyers who disliked the Jaguar's racier image. By the same token, rather than being unable to afford the difference for a Daimler, those who chose the Jaguar are unlikely to have regarded the Daimler as something they would wish to own anyway.

In total, the Daimler differed from the Jaguar in having:

a plastic insert on the rear number plate housing bearing the Daimler name. On the 420 the cast number plate housing bore the Jaguar name and on the Sovereign this remained beneath the plastic "Daimler" insert
wheel trim centres, horn button, oil filler cap and seat belt clasps carrying the stylised D rather than the title Jaguar, a Jaguar’s head ('growler') or no badging at all
ribbed camshaft covers bearing the inscription ‘Daimler’ rather than ‘Jaguar’, (although earlier versions shared the same polished alloy covers)
all of the 420 extras as standard, including a heated rear window, overdrive on manual transmission cars and power assisted steering
a flying D mascot at the forward edge of the bonnet in place of the leaping cat Jaguar mascot ('leaper') above the radiator grille
a fluted radiator grille with stylised D badge in place of the smooth crowned and Jaguar-badged grille
arguably more carefully selected and matched walnut veneer trim
higher grade Vaumol ventilated leather seat centre sections
better quality covers for the sun visors

Jaguar 420 and Daimler Sovereign (1966–1969)

Pedigree

Design

Styling

Interior

Engine

Mechanical

Performance

Daimler

Differentiation

Demise

Scale models

Specifications

External links

Further reading

References