THE WOLSELEY 4/50

Introduced at the 1948 Motor Show, the Wolseley 4/50 is the smaller brother to the 6/80, with a 4-cylinder 1476cc engine, & costing £904. It had walnut effect instrument panels, wooden glove box covers and door cappings, leather seats with Dunlopillo foam, and carpeting throughout.  The sales figures however were disappointing with only 8,950 sold over the full production run.

Introduced at the 1948 Motor Show, the Wolseley 4/50 is the smaller brother to the 6/80, having a 1476.53cc (90.1 cu in) ohc engine in place of the 6/80’s 6 cylinder 2214.8cc (135.15 cu in). Apart from the extra bonnet and wing length on the 6/80 the two cars are virtually identical but the 4/50 has a narrower radiator grille and only one auxiliary lamp on the front valance. Any cars that feature two lamps, will have had them added by the owners.

Staying outside the car, the 4/50 is identified by shorter front wing flanks between the wheel arch and “A” post, and by the lack of opening rear quarter-light windows. It also ran slightly narrower tyres – 5.50 x 15 cross plies, as opposed to 6.00 used for the 6/80.

The 4/50 at the time of its introduction, cost £904 and could have expected to be a sales success as there was little competition at this price level. The sales figures however, were disappointing at only 8,950 against 25,280 for the larger 6/80 for it its full production run, thus the 4/50 was discontinued in November 1952, making way for the technically simpler 4/44.

Under the bonnet the 4/50 and 6/80 engines are of similar design but the 4/50 has a manual choke as opposed to the 6/80’s electric unit (EED) which uses an auxiliary carburettor; a single 1 ¼”” SU main carburettor is used on the 4/50 whereas the 6/80 has a twin 1 ¼” set-up; and the 6/80 camshaft has a damper at the rear, which is not fitted to the 4/50.

The Wolseley 4/50

A fully restored 4/50 in metallic grey

The Club President with his 1952 4/50

The Hispano Suiza 8A V8 aero engine

The engine design is unique to the 4/50 (4 cyl) and 6/80 (6 cyl) cars, the valve train of which is based on that of a 1915 V8 aero engine (the Wolseley Viper, which powered the SE5A Biplane, made by the armaments company Vickers, the owners of Wolseley at the time, and produced under licence from Hispano Suiza during WW1, the Hispano version powered the French SPAD).

The 4/50 engine is classified as an “under square” low compression unit, factory “family number” VC15W. Often misquoted as “longstroke” the stroke is only slightly longer than the bore, but, far shorter than many contemporary marques of the era which had very narrow bores and far longer strokes (this was because of the RAC taxation system at the time) thus it is “short stroke” in comparison but should be more correctly termed “under square.

The 4/50 engine, like it’s 6 cyl counterpart, has a single overhead camshaft operating directly onto tappets which are screwed into the valve stems, adjustment being by a ratchet system. Split helical gears drive the camshaft from a vertical shaft at the front of the engine, which also operates the oil pump at the bottom and the distributor at the top.

The ohc engines (4 & 6 cyl) gained a reputation for burning out their exhaust valves after a relatively low mileage and there has always been much engineering debate as to why some engines were affected and others not.

It would seem fair to say that a combination of how the valves and guides operated, the materials they were made from, the use to which the vehicles were subjected and the poor quality low octane petrol of the time (which was a major cause of overheating and detonation/pre-ignition), were all contributing factors to the problem. For a more detailed explanation see “The OHC engines” page.

Any engines that may have experienced valve trouble will probably have been rectified by now. In the past, owners had their valves “Stellited”, which entailed the valves having a layer of very hard material welded onto the operating faces. This did not cure the inherent problem but made the valves last much longer before needing replacement.

For the benefit of its members, the club has commissioned the manufacture of exhaust valves for both Series I and Series II engines in high grade stainless steel, and phosphor-bronze exhaust valve guides. It is still possible however, to find a genuine low-mileage car where no additional engine work has been carried out and if previous owners have maintained their cars well (as was often the case years ago) there may not necessarily be any cause for concern. In any case, the club can help with new parts.

The club has never had a report of a newly manufactured valve failing.

The earlier engines were designated as the Series I but towards the end of 1952, before the model was discontinued, a redesigned cylinder head and cooling system with enlarged waterways was introduced, featuring longer stemmed valves which were designed to work at an improved angle. The Compression Ratio (CR) was also reduced from 7.0:1 to 6.5:1 to prevent detonation and “running on” after switch-off, a common problem when using the post-war low grade fuels which were all that were available at the time.

This later engine became known as the Series II and in the case of the 4/50, commenced from engine N° 10501-2.

Any engine (regardless of manufacturer) that is allowed to overheat will also create additional cylinder head problems, usually resulting in cracking of the head. Had the manufacturer seen fit to incorporate a temperature gauge as standard equipment, then early indications that the engine was getting too hot would have been spotted by the driver well beforehand!

The Wolseley 4/50 engine

The Club President’s 4/50 alongside a Wolseley 6/80

Early style dashboard, note the curved ends.

Series II dashboard, with revised vinyl top panel

With a well maintained engine, the Wolseley 4/50 can be a very easy car to live with. Not having to maintain the balance of the 6/80’s twin carburettors has distinct advantages for the 4/50 owner and its ability to keep pace with modern counterparts on the road can make for an altogether satisfying driving experience. The body was the first post-war design from Morris/Wolseley, being of monoconstruction as opposed to the pre-war separate chassis and body. All the 1948-54 club cars share the same body style as the Morris Minor “MM”. Rear suspension is by semi elliptic leaf springs whilst the front has torsion bars splined into wishbones.

The trunnion and swivel pin set-up of the front suspension was common to many other vehicles of the time – although in the case of the Wolseley 4/50, probably over engineered to some degree to cope with the weight towards the front of the car. As with any set-up of this type, the key to reducing any wear in the trunnion internal and swivel pin external threads is to ensure they are greased at the prescribed servicing intervals.

Even when this appears to have been carried out satisfactorily, blocked grease nipples and the failure of the grease to find its way around every component, can reduce the life expectancy of these items.

Shock absorbers were Armstrong hydraulic lever arm type on early cars, but modifications were soon made after introduction, to fit telescopic types (twin at each front wheel and singles at the rear).

Lockheed hydraulic drum brakes are fitted with twin leading shoes at the front.

The 4 speed gearbox has synchromesh on 2nd, 3rd and 4th gears and is operated by a lever mounted on the steering column.

Drive is through a single plate Borg & Beck clutch, prop shaft and universal joint, to a semi-floating hypoid rear axle.

A 1949 road test report quotes the car’s 0-60mph time as 31.6 seconds, and the average fuel consumption as 26mpg.

Internally the Wolseleys were a little more up-market than the Morris models, having walnut effect dashboard panels, wooden glove box covers, and wooden door cappings, but all versions had had leather seats with Dunlopillo foam, and carpeting throughout.

UK (Home market) 4/50’s were fitted with separate front seats, later models with “split bench” but most export models were fitted with bench seats unless otherwise specified by the customer.

Instrumentation consists of a speedometer, clock, and gauges for oil pressure, fuel and amperes.