New Model

10th November 1961, Page 154

10th November 1961

Page 154

Page 157

Page 154, 10th November 1961 — New Model

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ANNOUNCED this week, a B.M.C. 11-litre 40-b.h.p. diesel engine and a forward-control low-platform 5-tonner, equipped with an F.G. cab, are being exhibited for the first time at the Scottish Motor Show. The 18-ton gross-train-weight prime mover and 5.7-litre oil engine (shown to fleet users at the Morris Commercial Show at Longbridge in May) are also feature exhibits. Other new B.M.C. models include an Austin export-only 6-tonner and export versions of the Austin 1+-ton and 2-ton chassis with normal-control cabs in place of the forward-control type. Offered for application as an optional fitting for Austin and Morris 7-tonners in September last year, a five-speed gearbox is now available for 5-ton and 6-ton models and is a standard fitting on the prime mover.

Developing its rated net output of 40 b.h.p. at 4,000 r.p.m., the new 11-litre diesel has a dry weight of 422 lb., which is only 50 lb. heavier than the Corporation's B-Series li-litre petrol engine, the commercial vehicle version of which has an output of 42 b.h.p. at the same speed. The unit is available as an alternative to the petrol engine in Austin and Morris 10-12-cwt. and 16-18-cwt. light commercial vehicles.

Whilst the petrol engine develops a maximum torque of 73 lb.-ft. at 1,700 r.p.m., the torque rating of the oil engine is 64 lb.-ft. at 1,900 r.p.m., corresponding b.m.e.p.s being 121 p.s.i. and 107 p.s.i. respectively. Equipped with Ricardo Comet Mk. 5 combustion chambers, the diesel has a compression ratio of 23 to 1.

Features common to both units include a bore of 2.875 in. and a stroke of 3.5 in. The cylinder-block-crankcase assemblies are basically similar, and the rocker cover, back plate and various accessories are identical. This standardization is a valuable aid to production economy and has enabled the diesel to be offered at a cost only £85 more than that of the petrol engine.

It is emphasized by the makers that the use of replaceable wet-type cylinder liners is unnecessary, the standard type of cylinder block being employed for both applications. A cylinder-bore life of over 100,000 miles has frequently been achieved by B-Series petrol engines fitted to cars and commercial vehicles, and it is considered that this is comparable to the wear that would be provided by wet liners. The

diesel has five studs for each cylinder in place of t studs fitted to the petrol engine, and a new type of I employed, fabricated of steel, copper and asbesto: The injection pump of the oil engine is a CA tributor-type D.P.A. unit. and C.A.V. Pintaux noz used, the pressure rating of which is 135 atmospl 1,985 p.s.i. Injection is timed to start at 22° befc K.L.G. pencil-type (Ill V.) heater plugs are fitte( interests of easy starting in cold weather.

Solid-skirt aluminium pistons are fitted to the place of the split-skirt type and floating gudgeon employed, the pins of the petrol-engine piston clamped in the connecting rod. A chrome-faced t, pression ring, two taper-faced compression rings ; slotted scraper rings are common to both units. changes include the use of a more robust three

aaft to accommodate the higher stresses of the diesel, tailed modifications including an increase in the size crankpin diameter and in the thickness of the webs. ikpin diameter has been increased to 2.0005 in.n. from 1.8759 in.-1.8764 in., and the length of the bearings has been reduced from If in.-11 in. (to nodate the more robust webs) the journal diameter of in.-2.001 in. remaining unchanged. Steel-backed -lead bearings are used for the journals in place of netal bearings to withstand the higher loading, the ting-rod bearings of both engines being of the former The oil engine has a torsional vibration damper.

1 from an advance in exhaust valve closing from 10' ,d.c. to 50, the valve timing remains unchanged. tft drive is provided by a duplex roller chain, and .ust is taken at the front end. Also unchanged, the system has a capacity of 111 pints, and thermostat ; temperature is 164°F.

idicated by road tests of fully laden vehicles carried the makers, acceleration is very little affected by of the diesel engine, whilst a gain in fuel consump26-35 per cent. can be expected. The fuel consumpa 16-18-cwt. vehicle operating in urban conditions verage speed of 15 m.p.h. was 32.1 m.p.g. when a agine was fitted, whereas a consumption of 21 m.p.g. :orded by a petrol-engined vehicle.

Bored-out 5.1-litre Unit

11 be recalled that the B.M.C. 5.7-litre engine is a ut version of the 5.1-litre unit, the stroke of both being 120 mm. Bore size is increased from 95 mm.

nm. and the net power output has been raised from ). at 2,400 r.p.m., to 105 b.h.p. at the same speed, )nding gross outputs being 105 b.h.p. and 120 b.h.p., vely. Maximum torque output has been increased

;8 lb.-ft. at 1,500 r.p.m. to 255 lb.-ft. at 1,750 r.p.m. der for the higher output, element diameter of the pump has been increased from 71 mm. to 8 mm. four holes of the nozzles have been enlarged. is in-line injection pump is used, and the fuel is he pump through a Simms renewable-type filter. increase in bore diameter is accommodated by rig Sheepbridge Centricast Mk. 11 liners, the base

• f which is a modified 0-ring of reduced section, nore uniform stress distribution. Other modificaAude helical timing gears (in place of chains) fitted !ewable phosphor-bronze thrust washers. The idler ; an outrigged bearing in the casing.

iew 5-tonner is available in Austin and Morris and is the largest model in the range fitted with cab. It has a loading height of 3 ft. 5* in. Known .G.-K100 Low-Loader, the vehicle is supplementary iO4 5-ton chassis, the loading height of which is in. The reduction in platform height has been by using 17-in, wheels equipped with 8.25-17 tyres, the chassis-frame being similar to that d for the 504 model. Common to both models, the se is 13 ft. 4 in. and the chassis frame is also . Overall length is 23 ft. 44 in., whilst the body igth of 16 ft. 6 in. and the minimum ground clearin. The cab height of 7 ft. 6 in. is 5 in. lower than he forward-control 504 cab.

d with either the 5A-litre diesel engine or 4-litre 'gine, the vehicle has a modified frontal appearance. mrnodate the larger engine, the radiator has been 3rward and the cowling has been redesigned. All the pa switches of the 1962 F.G cabs are now clearly details include a 5.86-to-1 final drive ratio (ratios o 1 and 7.2 to 1 are optional) and the availability of an Eaton 13802 two-speed axle as an optional fitting. Because of the smaller wheels, brake-drum diameter has been reduced from 16 in. to 14 in., whilst the width has been increased, which provides a total lining area of 415 sq. in. This compares with 369 sq in. for the 503 and 504 models.

A fuel consumption of 17-18 m.p.g. is claimed for the oil-engined model when the vehicle is operating at high speed with a full load, the corresponding fuel consumption of the petrol-engined model being 9-10 m.p.g.

Offered in wheelbases of 150 in., 160 in. and 180 in., the new 6-tanner is known as the WE-K120 and is available with the 5.1-litre or 5.7-litre oil engine. Whilst the taxation weight of the I50-in. and 160-in, chassis-cabs is 2 tons 141 cwt., that of the 180-in, model is 2 tons 16 cwt. Gross vehicle weight is 10 tons 5 cwt. (23,000 lb.).

A normal-control WE type all-welded steel cab is fitted to all the versions, features of which include forwardopening doors, a divided windscreen, drop door lights and swivelling ventilators. Ample accommodation is provided for a crew of three.

Mechanical details include a four-speed constant-mesh gearbox (the five-speed box is available as an optional fitting) and a fully floating rear axle. Chassis powered by the 5.1-litre engine are offered with a final drive ratio of 7.2 to 1 or 6.67 to 1, the alternative ratios of a chassis equipped with the 5.7-litre engine being 5.86 to 1 and 6.67 to 1. Either type may be fitted with an Eaton 16802 two-speed axle with ratios of 6.14 to 1 and 8.54 to I.

Of pressed-steel channel-section, the main chassis members are of 11-in, material and have a depth of 9+ in. and a flange width of 3 in., the frame being equipped with seven cross-members.

In the case of the 180-in, wheelbase model, the overall length and width of the vehicle are 23 ft. 1 in., and 7 ft. 6 in., respectively. The maximum height when laden is 7 ft. 41 in. and the laden frame height is 2 ft. 7+ in. A front track of 66+ in. compares with a standard rear track of 68* in., which is increased to,681 in. if the two-speed axle is fitted.

In the case of the li-ton and 2-tan export models (with normal control cabs) the type numbers are S203 and T203, respectively. Both have a wheelbase of 10 ft. 9 in. and an 'overall length of 17 ft. 91 in., the distance from the back of the 'cab to the end of the frame being 9 ft. 41 in. Both vehicles are available with the 4-litre petrol engine or 3.4-litre oil engine.

Offered at an extra cost of £60, the five-speed gearbox provides ratios of 7.58 to 1, 4.38 to 1, 2.39 to I, 1.47 to 1 and (top) 1 to I. Reverse ratio is 7.51 to 1.