Around 3radford with a Bowan
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FOR over seven years . the Jowett has been marketed as o commercial vehicle; -previously for more than double that period Jowett cars had been making a name for themselves at home and abroad. During the whole of that long time—long, that is, for the comparatively new motor industry —the engine has been a twin-cylindered one; to-day in its most developed form it can give a good account of itself in rigorous delivery work and its rate of fuel use, as disclosed in these pages, is
pleasantly low. ..
In response to our request Jowett Cars, Ltd., Idle, Bradford, placed at our disposal a 7-cwt. van which, in all respects, was standard. We were informed that it had done very little running and the mileagerecorder reading of 24 miles confirmed that statement. Our trial .extended over some 80 miles, during which the performance was improving gradually. It would seem, therefore, that the figures given in this report might even be bettered in the ease of a vehicle having a eater distance to its credit.
A Fully Laden. Van.
Before any specific tests were undertaken the weight was checked and found to be 19 cwt. 2 qrs. 14 lb., so that the pay-load was actually some 7i cwt.—making an overload of cwt. This aggregate allows for our representative's weight being counted as part of the payload; normally, of course, only one man—the driver—is carried on such a vehicle.
A number of flywheel blanks was used to form the load and this was evenly distributed over the 040
floor. The general dimensions of the vehicle are worthy of note at this juncture :—Body capacity, 67 cubic ft.; interior height, 3 ft. 11-i ins.; interior width, 3 ft. 01 ins.; interior length, 4 ft. 10 ins.; vehicle length, 12 ft. 2 ins.; wheelbase,' 8 ft. 8. ins.; track, 3 ft. 9 ins. The annual tax is 110.
Comfortable Driving Position.
On taking over the chassis our first impression was of the large amount of legroom allowed for the driver; a second seat is provided in the cab for an occasional passenger. When long loads have to be carried this seat can, after a moment's work, be .removed. The steering column is more raked than on most commercial vehicles, but the driving position is a comfortable one and should not occasion fatigue on the longest day's run.
The left-hand gear lever has a long travel, whilst the hand-brake lever is situated to the drivers right and is inclined. This arrangement permits easy entrance from each side—two doors are provided —and each lever is well within reach. The gear change proved to be very easy, so there is no excuse for a driver hanging on to top gear when the engine begins to labour.
If the engine be properly handled there is no need to change down to second gear on ordinary inclines; the engine .responds to delicate handling of the ignition control on.. the dashboard in a remarkable way; particularly at low r.p.m. (Above) The petrol-tank position, dynamo and ignition system are clearly shown here. (Right, in circle) The gear lever is carried directly upon-the box, whilst the brake lever is on the right. (Right, in rectangle) The water-heated induction pipe prevents conden sation of the mixture.
When long stiff hills have to be tackled it pays to use the lower ratios liberally. On test we found that the road speeds on first and second gears were limited to about 14 m.p.h. and 31 m.p.h. respectively ; above these speeds valve bounce set In. On top gear the maximum attained was 48 mph. without adventitious aids
Top-gear Speed Range.
'At the other end of the scale it was found that the minimum sinooth-running speed on top gear without' clutch slip, was 8 m.p.h. Above 10 m.p.h, on the direct drive It was difficult to believe that the engine had but two cylinders. Transmission snatch and harshness were absent in all gears and the indirect ratios were as quiet as one expects on a modern vehicle of the van class.
Being manufactured in a hilly country the Jowett is designed to tackle single-figure gradients as a matter of course. On 1 in 6 a restart in either direction was effected with ease; the reserve of power and the capabilities of the clutch permit harder work than this to be done with ample safety. The choice of gear ratios is well stilted to van work and gives a good compromise between rapid hill-climbing and economical fuel consumption.
Before commencing the fuel-consumption trial the carburetter was dismantled in our presence and the jets were, in both eases, found to be marked 90, whilst the choke was stamped 23. The carburetter was reassembled and a special test tank connected to the float chamber.
The first test was of straightforward running, as on a mediumdistance, point-to-point journey. On one quart of petrol we covered 8.85 miles, including six changes to second gear and two further ones to first gear. The indirect ratios were in use; on hills for 1.7 mile. This rate of'Use equals 35.4 m.p.g. The speed averaged 22.2 m.p.h.
As a van of the type in question is used, in the majority of cases, for delivery work of a door-to-door nature, we prefer to test consumption on this basis. A further. trial was, therefore, carried out and the figures obtained are used as the basis of calculations, the results of which are embodied in the accompanying panel. A pint of fuel was measured into the test. tank and a distance of 4.35 miles wascovered before the engine stopped for want of fuel. This equals 34.8 m.p.g. on delivery-round work.
Delivery-round Conditions.
During the 4.35 miles there were four engine stops, four changes to second gear and two further ones to first, whilst the indirect ratios were in use for .95 mile. When on the move the normal cruising speed was about 26 m.p.h. on top gear, or 18-20 m.p.h. on second gear.
It will be realized that the conditions under which this test was carried out would be found in only the really 'hilly parts of this country. For a brand-new vehicle the result is very creditable.
The results of the braking tests are shown in an accompanying graph. The pedal and the lever were used in conjunction when taking the readings, although the same sets of shoes are expanded whichever control be used for the purpose. When descending long hills the ability to use the lever to operate the four-wheel brakes gives the driver an easier task than if it were necessary all the time to hold down the pedal. Naturally, the pedal is the more useful for traffic work. Neither lever nor pedal required any strenuous effort. The brakes worked with marked smoothness and caused no skidding on wet roads, A first-class level main road was used for taking acceleration-test data. The figures which are used as a basis of the graph concerned are the average of a series of trials. The ignition control was, of course, liberally used to enable the engine to give of its best. Under full load the van ran steadily and the suspension was satisfactory ; it is worthy of note that the semi-elliptic springs are all directly beneath the main frame members of the chassis and that the rear springs support the frame to within a short distance of its rearward extremities. In other words, there is very little frame overhang; this bids well for good service in everyday use. This is particularly important in cases where baddistribution of the load may cause temporary heavy stresses; a concentrated load of 7 cwt. placed close to the rear doors can be a very unfair burden.
Both the chassis and the van body are rigidly built and of simple construction, which features are essential if durability is to be obtained at an edonomical price.