IMPROVEMENTS IN THE 7-TON MAUDSLAY.
Page 14
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A More Powerful Engine Giving 75 h.p. is Adopted:
THE new Mandalay 7-tonner is fitted with an im proved long-stroke engine, the bore and stroke of which respectively measure 4..i ins. and 6 ins. On the test bench this engine has been found to develop something like 75 h.p., as against the 60 h.p. of the 5-in. by 5-in. engine. 14 ith a 4 to I compression ratio, a petrol consumption of .57 pints per horse-power has been obtained, .60 pints per horse-power being the average figure.
The engine is equipped with a stouter crankshaft the timing gear being at the rear, the overhead cam shaft being driven by a vertical shaft and bevels. The camshaft is enclosed in an aluminium case, it being possible to dismount both case and shaft by removing the four nuts securing them to the cylinder head. The vertical camshaft drive is equipped with a telescopic splined joint, by means of which the top half can easily be drawn away At the lower end of this vertical shaft there is a cross-shaft driving the magneto on the off side and the water pump on the near side. The camshaft is mechanically lubricated, the overflow of oil returning to the crankcase. A new type of connecting rod, new bigend caps and a stiffer crankcase are other features of interest. The fan is also of a new type, and is driven by a wide belt, the circulation of air being further improved by a louvre in the 'under shield-, and a slit in the bulkhead which separates the
with the driver sitting practically alongside, it allows such parts as plugs and carburetter to be reached quickly. The cab is mounted on a 'subsidiary frame above the main frame, the engine itself being carried by means of four arms on a special under frame. The 'body space provided measures 19 ft. 6 ins., the wheelbase being 19 ft. 6 ins.
Turning now to the chassis, one notes that the brake drum on the propeller shaft has been increased in width to 5 ins., aluminium shoes lined with Ferodo being fitted. The brakes on the rear wheels are 4 ins, wide and 24 ins.in diameter, the brake gear itself having been considerably simplified. All four wheels run on Hoffmann roller bearings, central pivot steering being a feature of the design of the drop-forged front axle. The rear axle is a solid forging, and incorporates the usual double reduction gear, the reduction being 64 to 1. This, in conjunction with the 5 to 1 reduction in the gearbox, gives low gear of 41+ to 1. Several of these 7-tanners are already doing good work in Lancashire.