AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

Priva te-car Refinements Offered in

5th December 1947
Page 42
Page 43
Page 44
Page 42, 5th December 1947 — Priva te-car Refinements Offered in
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

ANEW LIGHT VAN

WITH changes in chassis and

. body design, the new

Comrner 8 cwt. Supervan. specification now includes the Synchromatic "crash proof" gearbox, which is actuated by finger-tip control below the steering wheel.

The well-tried side-valve engine, with minor modifications is standardized, and the earlier general layout of the transmission and suspension units, which also have been modified in the light of experience and developments, is retained. Lockheed braking is now employed, with the two-leading-shoe system on the front wheels.

Narrower and deeper piston rings are used to give more efficient oil control and increased pressure, and detachable plugs, fitted to the oil gangways, simplify the cleaning process at overhaul. The crankcase and cylinder block are an integral casting, with a detachable cylinder head. Operated by the three-bearing harmonic-cam camshaft, the valves are retained in detachable guides and the exhaust-valve seats are renewable.

Lubrication is by forced feed with extra-large-capacity oil pump. Incorporating an air silencer and fed by an A.C. mechanical pump, the Solex down draught carburetter has exhaust-heated hot-spot control for easy starting.

An outstanding innovation in the chassis, the Synchrornatic gearchange control lever is mounted just below the steering wheel, providing a finger-light action. It is connected to L shaft mounted parallel with the steering column, and the action is transmitted both circumferentially and longitudinally to the selector levers.

Longitudinal movements of the c4 shaft are caused by a bell crank, which, linked to a further lever on the gearbox, determines the selector lever to be operated. This would correspond to a gate movement on a normal control. The control shaft that imparts rotary movement is linked with the selector shafts to give the required travel to engage the gears.

As a safety measure which prevents reverse gear from being accidentally engaged, the knob of the lever has to be pulled out against a spring to obtain the desired position. Based on the synchromesh principle, a baulking ring is interposed between each synchro-hub assembly to assist in producing a light, smooth and quiet gear-change.

In action, the initial movement of the control lever shifts the synchrosleeve and shifting plates into contact with the baulking ring. This causes the baulking ring to rotate through a controlled arc; further movement on the lever engages the tapered surfaces of the synchro and baulking gears, which synchronizes their speed. As soon as the speeds are compensated, the baulking ring, permits the synchronizing sleeve to slide into full engagement with the dog clutch. Employing this principle, it is impossible to make a noisy gear-change and the speed of the change is proportionate to the pressure applied to the control lever.

Clutch operation has been modified, having regard to engine movement in relation to the pedal, which is rigidly mounted on the chassis. The pedal is now linked to the control lever by means of a chain, 'which avoids the transmission of engine oscillation to the clutch pedal.

Both front and rear springs incorporate a greater negative-camber bottom leaf, providing a progressive action to the suspension on increased loadings. Rubber pads have been interposed between the rear springs and the axle to damp out the highfrequency vibrations, which would otherwise be transmitted through the springing to the frame. Silentbloc bushes are fitted to both front and rear springs.

Employing the latest Lockheed braking system, the fluid reservoir tank is an integral component with the master cylinder, a cover plate in the floor providing access to the

reservoir for topping up. Brake adjustment is provided through a

hole machined in the brake drums, which can be aligned with the adjuster, the desired brake clearance being obtained by inserting a screwdriver through the hole to turn the adjusting screw.

The frontal appearance has been subjected to major alteration to bring it into line with modern design. Flush-fitting, pre-focused, sealed-beam combined side and head lamps are recessed into the front wings. Adjustment laterally and vertically .

is facilitated by three spring-loaded stop screws, against which the reflector unit abuts when it is in. position.

The sealed-beam unit prevents maladjustment and is completely waterproof. A twin-filament bulb fitted to the near-side head lamp provides a dipper and anti-dazzle effect.

The radiator grille is narrower than before and is no longer carried by the alligator bonnet. The bonnet catch is controlled by a knob mounted under the facia panel, and a double-catch safety device prevents the bonnet from being opened until the second locking pawl has been shifted manually. This prevents the bonnet from flying open while the vehicle is moving should the first pawl not be correctly engaged..

The starting-handle boss is concealed by two spring-loaded bars of the radiator grille, which have to be lifted against spring pressure to allow the handle to be inserted.

A three-spoke steering wheel provides a clear view to the sloping instrument panel immediately in front of the driver. An additional rack space provided in the roof of the cab could be used to house the driver's record books.

The windscreen is fixed, and the wiper motor, which is housed under the bonnet on the near side, is controlled by a push-pull knob mounted on the facia panel. Dual wiper blades are provided.

For the purpose of our road test the chassis was loaded to the maximum weight and, with the driver and myself on board, it turned the scale at 1 ton 11 cwt.

After an initial .run of a few miles to get the engine and gearbox warmed to normal working temperatures, the fuel-consumption test was started. A 13.5-mile stretch of the Luton-Bedford road was chosen, and an out-and-return journey brought c6 the total distance covered to 27 miles.

The first test, which was a straight run with only one stop, made on 'turning at the end of the outward journey, was covered in slightly over 52 mins., which gave an average speed of 31.1 m.p.h. A measured quantity of 0.80 gallon of petrol was added to bring the level of the fuel back to the initial starting point on the measures. This equals a consumption rate of 33.75 m.p.g. A second test, representing conditions of local delivery, resulted in a consumption figure of 21 m.p.g., the same route being covered, with four stops to every mile.

Lively Acceleration

On a level stretch of road, the acceleration figures showed that a lively performance could be expected from the Commer. Acceleration tests through the gears proved that 20 m.p.h. could be accomplished in 5 secs., 30 m.p.h. in 12 secs., and 40 m.p.h. in 22 secs. Incidentally, the 30 m.p.h. and 40 m.p.h. readings were taken in third speed, a change to top gear being made at 43 m.p.h.

Accelerating in top gear from 10 m.p.h., 20 m.p.h. was attained in 8 secs., and 30 m.p.h. in 19 secs. The brake-test figures were so remarkable that four readings were taken at 20 m.p.h. and 30 m.p.h. to make certain that no mistake had occurred. In both cases 100 per cent. efficiency was attained, and repeat runs failed to disprove the stopping distance of 13 ft. from 20 m.p.h. and 30 ft. from 30 m.p.h.. From the tyre marks on the road it was observed that the brakes had applied evenly on all four wheels, and, although the marks were heavy, there was no trace gof wheel locking.

Having put the Commer through 50 miles of arduous work, I carried on to climb Sharploe Hill, at the foot of which a stop-start test was staged. I started from rest in bottom gear, gained second gear, but could not make sufficient engine revolutions to complete the climb in third, 'The radiator temperature at the end of the climb was in the region of• 190 degrees F., an atmospheric temperature of 37 degrees F. being recorded.

As' the radiator appeared to be on the warm side, I ran a further five miles to obtain a normal working temperature, which was found to be 167 degrees F.


comments powered by Disqus