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The "Little" Things that Count

EVERY goods-vehicle operator with, technical knowledge and a creative mind has had the desire to build a chassis to his own design, making use of proprietary units and parts offered by the component and accessory manufacturers. Many have pursued this ambition to the extent of modifying and reequipping an old chassis to provide a service on a particular kind of job.

Passenger-vehicle operators are , equally anxious to reduce costs and improve performance by attention to detail, and both classes of operator, together with vehicle manufacturers, realize that a comprehensive knowledge of proprietary-unit and component developments is a necessary qualification for planning ahead.

The specialist designer and the operator with expert knowledge of practical problems will rub shoulders on the component and accessory stands at the Commercial Motor Show to study similar subjects from

different angles. .

Smaller Oil Engines Reducing the size of oil engines to compete with the private-car type of petrol engine, which is backed by a widespread maintenance organization, is a trend which will be given impetus by the production of the P3V threecylindered 32 b.h.p compressionignition unit, to be exhibited for the first time by F. Perkins, Ltd., on Stand 419. The bore and stroke and other essential features are similar to those of the P4 and P6 units, and the speed at which maximum power is developed is the low figure of 2,000 r.p.m. The torque developed is 123 lb.-ft.

It is perhaps necessary to dispel a misconception, often attributed to small operators, that the balance of a three-cylindered engine is inferior to that of fourand six-cylindcred engines. Its balance is identical to the balance of a "six," and the rocking couple which is produced is effectively accommodated by modern designs of mounting. This also applies to a fivecylindered unit, which is in perfect balance, but has a readily absorbed out-of-balance couple.

The 5HLW engine, which will be shown by Norris, Heqty and Gardners, Ltd., on Stand 220, has the distinction of being the only five-cylindered unit to be offered in horizontal form._ It is based on the standard 5LW unit with a bore of 41 ins, and a stroke of 6 ins., these dimensions being similar to those of the 4LW, 6LW and the horizontal six-cylindered engine, the FifILW.

The capacity of the 5LW is 7 litres and the power developed 'is 94 b.h.p. at 1,700 r.p.m. A notable feature of all Gardner engines, including the 4LK, is that the crankshaft is unhardened and

runs in bronze and steel bearing shells lined with white metal. The 4LK has a bore of 31 ins, and a stroke of -5f ins. and devflops 57 b.h.p. at 2,100 r.p.m.

Another newcomer to the underfloor range of engines will be the horizontal version of the Perkins P4V unit, based on the vertical engine with the same type number, developing 52 b.h.p. at 2,400 r.p.m. Its, overall height is reduced to a minimum by a special form of sump, and the fuel-injection pimp is mounted at the tear for ease of maintenance.

15.9 Litres, Turbo-charged

Exhibited for the first time sit the 1950 Show, the 6DC970 exhaust turbocharged 15.9-litre oil engine will again be displayed by Henry Meadows, Ltd. (Stand 372). The power output has been increased from 260 b.h.p. to 270 b.h,p. at 1,650 r.p.m., and the specific fuel consumption has been reduced to 0.381 lb./b.h.p.-hr. Following Meadows practice, the bore and stroke dimensions are the same, being 150 mm., compared with a bore and stroke of 130 mm. of the 6DC630, the 6P0630 and the 4DC420 engines.

The smallest Meadows unit, the 4DC330, has a bore and stroke of 120 nun. and develops 80 b.h.p. at 2,200 r.p.m. The piston speed at the rated r.p.m. is 1,735 ft. per min. and its specific fuel consumption is 0.39 lb./ b.h.p.-hr. Both the four-cylindered engines are fitted with an internal harmonic balancer to eliminate secondary out-of-balance forces.

The 6PC630 is a petrol version of the 6DC630, developing 180 b.h.p. at 2,400 r.p.m., compared with an output of 130 b.h.p. at 1,900 r.p.m. of the oil engine.

Of interest in connection with the development of small oil engines will be the exhibit of the new SPE-series fuel-injection pump by Simms Motor Units, Ltd. (Stand 230), which has been designed specifically for small highspeed unitsoperating under adverse conditions. An important feature of the pump is the large surface area of the plungers, which have a high resistance to abrasive action and consequently a long wearing life. The increased area has been obtained by making the control edge of the plunger in the form of a groove which communicates with a central passage. The groove occupies a small proportion of the total cylindrical surface.

The design of the control mechanism and governor is also unusual. Each plunger is connected to a lever which fits into a forked attachment on the square control rod, and the fork can be moved in relation to the rod for calibration purposes. The lever radius is comparatively large and any backlash as the result or wear is reduced to a minimum.

The governor is of the conventional pneumatic type, in that use is made of manifold vacuum as the control medium, but the design is of particular interest because the diaphragm chamber is connected by two pipes to the air intake, one on the engine side of the butterfly valve and one on the atmospheric side. Pressure variations in the outer pipe are controlled by a needle-damping valve attached to the diaphragm, and a progressive governor response to throttle movement is obtained, giving steady idling and controlled performance over the speed range.

C.A.V., Ltd., fully recognizes the importance of providing injectionpump governor characteristics to suit users' requirements, as will be shown by the display on Stand 232 of pumps

with hydraulic, mechanical and pneumatic governors. An NL6E enclosedcamshaft pump fitted with a weight-type governor will he shown sectioned and in motion. This pump is provided with a built-in final filter to trap any dirt which may pass the main filters during servicing.

A range of fuel-injection equipment will also be displayed by Scintilla, Ltd., on Stand 412, and the Automotive Products Co., Ltd., will exhibit Micronic oil and fuel filters with plastic-impregnated paper elements and metal-element filters on Stand 356. Equipment to be shown by Vokes, Ltd., on Stand 279, includes fuel and oil filters, exhaust silencers and the Gasmaster distribution' rectifier for petrol engines.

The Glacier Metal Co., Ltd. (Stand 218), will also have an example of its new centrifugal filter, in which the oil pressure in the lubricating system of the engine provides the power to drive the drum or rotor of the oil cleaner at high speed. The rotor, which is mounted on white metal bearings. forms the receptacle for the deposits flung out from the main body of the oil. Although the specimen to be shown will be an inbuilt component of an Albion engine, types that can be fitted as an auxiliary to most engines will probably be made available.

Pistons, piston rings, valves, cylinder liners and crankshaft bearings form a group of components which are generally the first concern of maintenance engineers. Of special interest in this connection will be displays of pistons and rings by Specialloid, Ltd., on Stand 261, by Hepworth and Grandage, Ltd., on Stand 273 and by

Wellworthy, Ltd.,. on Stand 359. A range of piston rings for original equipment installation and replacements will be shown by the Cords Piston Ring Co., Ltd., on Stand 259, and a special feature of the exhibits of the Laystall Engineering Co., Ltd., on Stand 214, will be Cromard plated-steel cylinder liners.

Ample evidence that the Cromard chromium-plated liners show negligible wear after 100,000 miles of normal running will be available on the Laystall stand. The liners are plated by the electrolytic process for the full length of the bore and are prefinished before leaving the factory. They are produced in over 100 standard sizes.

Cylinder liners of various types will be exhibited by Hepworth and Grandage and by Wellworthy; the latter concern will also display valveseat inserts and bearings. Cylinder liners to be shown by the Harold Andrews Grinding Co., Ltd., on Stand 283, comprise Hagco cast liners of Silmocrom and austenitic materials. Laystall will stage a number of exhibits showing the reconditioning service offered for cylinder sleeving and grinding, crankshaft grinding and the welding of broken or damaged parts.

A featured exhibit on the Specialloid stand, to be shown for the first time,' will be a chromium-plated armouring ring, designed to reduce ring-groove wear and to provide for reconditioning worn grooves when new rings of standard dimensions are fitted during an overhaul. The range a pistons displayed by Hepworth and Grandage will comprise Heplex silicon-alloy and castiron types for oil engines, and pistons in both materials for petrol engines, including split-skirt aluminium types. Wellworthy pistons of aluminium and cast iron will be exhibited, with examples of anodized and tin-plated finishes, and Al-Fin heavy-duty pistons having molecularly bonded austeniticiron ring carriers. The range of centrifugally cast cast-iron piston rings will include chromium=plated types and .Superslot and Duaflex oil-control rings. The'Duaflex is tensioned by a two-way steel spring and is widely used by operators when reconditioning 'worn engidea.

Hardened Liners Wellworthy cylinder liners are also centrifugally cast, and a special feature of the range will be hardened and tempered liners, a which thisconcern is one of the few manufacturers in Great Britain. The valve-seat inserts to be displayed are produced in a variety of creep-resisting materials, and some will be ,shown Stellited. Main and big-end bearings of W85 aluminium alloy will be of particular interest to those who have been watching metallurgical developments.

The thin-wall bearings and wrapped bushes to be shown by the Glacier Metal Co., Ltd., on Stand 218 are of white metal or copper-lead and are steel backed; the thick-wall bearings are available with the same linings, backed with steel or bronze. The bearing range to be exhibited by The Hoyt Metal Co. of Great Britain, Ltd., on Stand 211, includes steel-backed copper-lead bearings, solid lead-bronze bearings and die-cast all-white-metal bearings.

The Cords Oilguard ventilated-type oil-control ring, which has not been exhibited before, is of the threesegment type with two plain elements and an inter-element wave-form expander. The Cords cupped ring comprises a number of radially curved segments, fitted back-to-back to form a structure similar to that of a bellows; both rings minimize oil pumping losses in worn cylinder bores.

Comprehensive ranges of engineaccessory electrical equipment, including dynamos, starters and control units, B42 will be shown on the C.A.V. stand, and also by Joseph Lucas (Electrical), Ltd., on Stand 233. The C.A.V. units include trolleybus dynamos, one of which is a motor-generator unit and another an overhung generator.

A new C.A.V. product to be shown is a combined switchboard, fusehox and regulator unit, which is primarily designed for goods vehicles, but may also be used for the smaller types of

passenger vehicle. Simplified wiring,

replacement of switches without /removal of the switchboard from the vehicle and ready fuse accessibility are valuable features of the unit.

The Scintilla range of electrical equipment will include the well-known vertical (Vertex) magnetos, horizontal magnetos with and without automatic advance mechanisms, starters, dynamos, switchboards,. and so on. The Zenith Carburetter Co., Ltd., will again make a special feature of the master car

buretter on Stand 210, and on Stand 203, Solex, Ltd., will show the concern's range of governor carburetters, production carburetters and spares kits.

The electrical equipment to be shown by Delco-Remy-Hyatt, on Stand 410, includes ignition coils, replacement magnetos, heating and ventilating systems, cab heaters and transmission actuating motors.

T-orsional-vibration dampers represent a new production field for Girling, Ltd., and a number of these dampers for use on crankshafts, camshafts and transmission members will be shown by the concern on Stand 268.

Transmission components have probably been the subject of more research in relation to their net production cost than any other automotive assembly group, and this year a number of exhibits will provide evidence that the tempo of development has been well maintained.

Such exhibits will include the new A.S. strap-drive clutch to be shown by the Borg and Beck Co., Ltd., on Stand 342; the control unit giving fully automatic gear changing in the hydraulically actuated gearbox to be displayed by Hobbs Transmission, Ltd., on Stand 405; the featured demonstration, on Stand 315, by Self-Changing Gears, Ltd., of the M.W. automatic gear-Control applied to power-operated Wilson gearboxes, and the exhibit in production form of the electric-shift gear for Eaton two-speed axles, to be shown by Eaton. Axles, Ltd., on Stand 256.

The, drive from the cover to the pressure plate of the Borg and Beck A.S. 12-in. and 13-in. clutches is by means of. four pairs of tempered-steel straps, which are arranged tangentially so that the relative position of the two elements 'concentrically is not disturbed when the pressure plate moves.

Smooth Drive Layrub flexible clutch plates (Laycock Engineering, Ltd.—Stand 249) have rubber trunnion blocks which transmit the drive from the centre to the friction plate and provide a smooth take-up in accordance with a wide range of transmission. torsional. vibration characteristics.

The Hobbs manually controlled gearbox has been fully tested in service, and according to the expert opinion of an operator, the advent of the automatic control, which is of simple construction, will enable fuel consumption to be reduced and will save wear and tear of .the engine. The SelfChanging Gears M.W. control determines gear changing in accordance with the speed of the input shaft and fuel-injection characteristics, and an overriding manual control may be brought into use by the driver.

Electrically controlled gear-change mechanism which can be fitted to Eaton two-speed axles is now in full production. Its Operation is completely independent of vacuum or air pressure, and the control gear is particularly suitable for use on many types of oilenginecl vehicle in which neither of these two sources of power is available.

An official announcement regarding future developments will be made by the concern at the Show. This will relate to the production of a singlespeed axle and of a tandem-drive axle, with and without a third differential.

The 542 gearbox to be shown on Stand 229 by the David Brown Companies, will be one of four representa tive types. It is a five-speed unii designed for medium-capacity vehicles and may be fitted with either direct or overdrive top gear.

An important feature of Hardy Spicer universal joints (Hardy, Spicer and Co., Ltd.—Stand 225) is that the trunnion assembly, known as the journal kit, can be quickly replaced; a factory reconditioning service, based on standard charges, is available to all users. An electrically operated demonstration unit will be used on the Laycock stand to show the radial flexibility and axial-displacement potentials of the Layrub flexible joints.

A front-wheel-drive axle, a quarter-scale model of a 25-ton axle, and a hypoid rear axle for a rear-engined coach will be included in the exhibits of Kirkstall Forge Engineering, Ltd., on Stand 417, and a new 7-ton rear axle is to be shown by the Moss Gear Co., Ltd., on Stand 209.

The side shafts of the Kirkstall .front-wheel-drive axle are driven by a central bevel-gear differential and transmit the torque to the wheels through two constant-velocity universal joints and a hub planetary gear. The 25-ton axle is designed for a tractive effort of 50,000 lb., the primary reduction being by worm gearing and the secondary reduction by planetary hub gears. The hypoid pinion of the rearengined-chassis axle is offset above the axle centre line to accommodate the drive; the unit is designed for a gross load of 9.3 tons and to transmit 100 b.h.p. An oil pump maintains a constant circulation of lubricant.

New 7-ton Axle

The Moss 7-ton axle is an addition to the range of 3-ton and 6-ton axles, normally fitted with hypoid drive, which can, if necessary, be supplied with spiral-bevel drive. Another Moss display of interest will be a two-speed hypoid differential which can be incorporated in any of the standard axles. .

News of an important brake development is of great interest to everyone in the road transport industry, and among the highlights of the Show will be the Hydra-Static disc brake of Girling. Ltd. (Stand 268), and a mechanically operated version of the brake for mounting in the transmission.

Braking effort is applied by a series of pads to a small segment of the disc, pressure being exerted from both sides. The outstanding advantage of the brake is its high rate of heat dispersal, and it is self-cleaning in that moisture and foreign matter are thrown off the disc by centrifugal force. Replacement of the pads can be made in a fraction of the time required to reface conventional brakes, and tests have shown that the rate at which the pads are worn is comparable to the wear of drum brakes, despite the small friction area of the pads. Other Girling brake exhibits will include heavy-duty, twoleading-shoe and high-lift types.

Air Brakes

A new type of compact cylinder to provide the increased front-wheel braking load required by underfloorengined chassis with forward-mounted cabs will be exhibited by the Clayton Dewandre Co., Ltd„ on Stand 418. The cylinder has tandem pistons opt1taking the camshaft by a single lever and represents the latest type of frontwheel servo unit in the triple servo system.

A full range of air-pressure equipment will include a dual brake valve, designed for heavy vehicles and trailers, direct-acting brake cylinders for backplate mounting, and a sectioned model of a 15-ft. air compressor. The new strut-brake adjuster for high-tempera-. ture operation will also be shown.

In addition to pressure-brake equip-. ment for heavy goods vehicles, luxury coaches, double-deck buses and trailers, the Westinghouse Brake and Signal Co., Ltd. (Stand 386), will have a simplified system for a' light goods vehicle, incorporating a belt-driven, engine-lubricated high-speed compressor.

On Stand 345, the Lockheed Hydraulic Brake Co., Ltd., will exhibit a full range of Phase 3 hydraulic brakes with two-leading-shoe front units for light commercial vehicles, the Hydrovac servo system, a layout of the continuous-flow-accumulator servo and a fully power-operated system. The chief exhibit of Feeny and Johnson, Ltd., on Stand 398, will be the new control valve with which the braking effort on a trailer can be regulated to suit the load carried.

Concerns which will exhibit shock absorbers include Girling, Ltd., Newton and Bennett, Ltd. (Stand 207), Jonas Woodhead and Sons, Ltd. (Stand 252), and Universal Dampers, Ltd. (Stand 402), In the Girling PVN piston type, a recuperating chamber is mounted in the upper part of the damper and is readily accessible for adjustment without draining the oil; the number of scaling plugs is reduced to a minimum. thus decreasing the potential points of leakage. All the ,concern's telescopic dampers incorporate the NF antiaeration device. In the wide range of Newton telescopic shock absorbers are units for the replacement of arm-type dampers.

The complete range of WoodheadMonroe telescopic shock absorbers will include a number of sectioned models to show their internal construction and the operation of the working parts. Among the recently introduced Telatlo dampers, to be shown by Universal Dampers, Ltd., are then for mediumweight commercial vehicles and a T3 heavy-duty type. The working principle of these telescopic units is, in part, a function of the compression of an air-filled rubber ball and the design eliminates the need for an annular recuperation chamber. ' Frothing and aeration are eliminated.

Flexible -bearings for mounting engines, gearboxes, coach bodies, instruments, and so on. to be shown by Silentbloc, Ltd., on Stand 320, include the Frustacon mounting, which can accommodate widely differing deflection rates. Metalastik, Ltd., will display the full range of the concern's flexible mountings, shackle pins and couplings on Stand 282.

The Flexitor trailer suspension. based on a rubber bush in shear, will be seen on Stand 274 of the Brat-0er Engineering Co., Ltd.

Chassis lubricators will be on view by Tecalemit, Ltd. (Stand 378), and the Clayton Dewandre Co., Ltd. The Tecalemit Syndronic lubricator is mileage controlled, and . the two Clayton-Dewandre systems are a beltdriven-pump type and one actuated by the brake pedal.

Production Technique

Exhibits relating to various aspects of production technique will be on view on a number of stands. These include the displays of the latest " square " engine cylinder block and Mon ikrom high-duty iron camshafts by the Midland Motor Cylinder Co., Ltd., on Stand 291.

Joseph Sankey and Sons, Ltd., will exhibit a range of wheels and the individual pressings which make up a chassis frame on Stand 216. The wide variety of components to be shown by Rubery Owen and Co., Ltd., on . Stand 219, include chassis frames, many types of axle, road wheels and a number of pressed-steel components.

On Stand 353, the E.N.V. Engineering Co., Ltd., will display hypoid, double-reduction and two-speed rear axles of various types, together with gears and camshafts.