T RAFFIC lights, pedestrian crossings, slow moving traffic and the numerous
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oth,er obstacles encountered by vehicles on town delivery work, normally cause a comparatively heavy fuel consumption. However, the Bradford van, with its flexible engine power, 'set a high. standard of fuel economy on a 50-mile local delivery run, which included all these hazards, during
The Commercial Motor" road test.
On the weighbridge the van proved to be a featherweight for its class by tipping the scale at a mere 14 cwt.—a feature that probably contributes laigely to fuel economy The engine offers advantages of weight-saving, because, being a flat two-cylindered unit, it has a short crankshaft and crankcase, and, of course, other moving parts are somewhat lower in weight than those of a fourcylindered model.
High Torque at Low Speeds
With a bore of 3t ins, and a 4-in. stroke, the engine develops a maximum of 19 b.h.p. at 3,000 r.p.m., a feature being high torque at low speeds, which provides a high performance.
Plain, white-metal bearings are used fore and aft to support the crankshaft in the crankcase, the end thi ust of the shaft being taken by a flange on each of the bearings.
The camshaft, carried in two plain bronze bushes, is linked to the crankshaft by chain, an auxiliary drive to the distributor being taken through a skew gear. Each of the solid-pattern tappets is fully enclosed in a split casing, which can be readily removed for tappet adjustment.
. A V-belt drive from the crankShaft drives the dynamO, which, like all the c4 •
other accessories, is located on the upper part of the crankcase. Normally, it is not found necessary to fit a fan, the radiator being adequate for cooling.
A three-piece induction manifold links the centrally positioned Zenith horizontal carburetter to both cylinders. As the manifolds are of considerable length, the bores grow progressively larger towards the cylinders to avoid starvation at the higher engine speeds.
Unlike most engines, in the Jowett the clutch housing is formed from the gearbox casing and the upper half is left open to facilitate clutch-toggle adjustment, a point much appreciated by servicing crews The gearbox has conventional straight-tooth gears for first and third ratios, with double helical gears for the second speed. A cushioning effect is obtained on the clutch by using a centre plate of spring steel, which is cut in staggered vanes, brass-bonded asbestos being used for the friction member.
A Layrub one-piece shaft connects the gearbox and final drive of the semi floating rear axle, the differential being driven through a spiral-bevel, unit. The Girling brakes, operated entirely through pull-rods in tension, are fully compensated and ,easily adjusted.
The frame side-members are of channel section with four tubular cross-members. A point worth noting is the width of the frame, which, by reason of its wide spring anchorages, reduces any tendency to roll on corners. Luvax shock absorbers assist the semi-elliptic springing in the same respect. Silentbloc bushes fitted to the springs reduce the number of greasing points for general servicing.
The petrol tank is located within the chassis frame in a well-protected position. Fuel is delivered tO the engine through an AC fuel pump driven by the engine crankshaft.
The Bradford for our test was collected from the test bay at the works, after having completed the normal routine test, the reading on the speedometer showing well under 100 miles. After a tour of the outskirts of Bradford to test out its capabilities in hill-climbing, the van was brought to 'London at a steady