A NEW SIX-CYLINDER CHASSIS
Page 67
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for
Passengers or Goods
TO meet the demand fora powerful and fast chassis for passenger or goods vehicles the International Harvester Co., of Great Britain, Ltd., is marketing the SF46 type, which has been introduced to the British market after a successful debut in America, It may be used for the transport of 21 tons of goods or as the basis of a 20-seater coach or bus. In either case the risk of overloading is ever present and, consequently, the maker has fitted auxiliary quarter-elliptic rear springs, which come into action when the main springs .reach a certain point in their range of deflection, These also serve the purpose. of checking excessiverearaxle rise when an unusually severe road inequality is struck at speed.
Ample body space is etforded — nainely, 14 ft. 51 ins, from the scuttle dash to the end of the frame— whilst the wheelbase is 13 ft.
ink.. and the overall length 19 ft. 31 ins. Despite these dimensions the radius of the filming Circle is only 29/ ft. The track of the front wheels is 4 ft. 10 ins,. that of the rear wheels being I in. greater, • The allowance for coachwork between the rear wheels is 3 ft. 91 ins., the' frame height, when laden, being 2 ft. 61 ins.
Pressed-steel channel-section frame members are employed, each_ 71 ins, deep, the metal being 1 in. thick. Six cross members brace the frame at important points and there are two intermediate crossmembers. A banjo-type rear engine bearer is employed ; this serves also to brace the frame and is bolted to the rear face of the clutch pit. A single mopnting is employed at the front of the power unit.
Semi-elliptic springs are fitted fore and aft, the rear ends of each being shackled. The aforementioned auxiliary quarter-elliptic springs for the rear axle are clipped -to brackets above the front ends of the main springs and come into
use only when the semi-elliptic springs have passed a certain point in their travel.
Detachable steel-disc wheels carry 32-in. by 6-in. pneumatic tyres, singles being employed for the front wheels and twins for these at the rear. Mounted on the front axle are the levers which apply the Bendix three-shoe brakes. The operating Mechanism is very simple and there is nothing -Which can be put out of action by mud. The rear brakes are also of the internal-expanding type, having frietion ' surfaces of 5-in. width. The hand lever operates separate shoes in the rear-wheel drums.
The final drive is by spiral-bevel gear, With a ratio of 6.125 to 1. Roller hearings are used in the differential and
wheels, whilst there are ball bearings for the two-piece propeller shaft.
A monobloc casting is . used for the six cylinders of the L-headed engine ; the head is detachable, the valves being .situated on the near side. The capacity is 223.8 cubic ins., the bore and stroke being 31 ins. and 44 ins. respectively.
Water circulation is by centrifugal pump, the shaft of which is an exten sion of the dynamo armature. The latter auxiliary is spigot-mounted into the rear face of the timing case. The starter is also mounted in the same manner on the off side of the clutch pit. The oil filler and oil gauge are on the same side of the engine. The magneto is of Boseh make and is carried above the ' dynamo. .
Generous bearine.area is a distinctive feature of the crankcase, the total being no less than 18.5 sq. ins. The bronzebacked, babbit-lined bearinp are bored and broached in one operation to secure perfect alignment. Full-pressure lubrication is employed, the entire system being in the upper half of the crankcase. The crankshaft is statically and dynamically balanced. The cams are
integral with their shaft and the contours incorporate quietening curves.
A double-plate dry -clutch is housed in a pit, the upper portion of which is in one with the corresponding half of the crankcase. The lower section of the pit is detachable and there is an inspection plate in front of the gear lever to permit access to the clutch for lubrication and adjustment. The gearbox is bolted to the clutch pit and provides four forward ratiOs. All the pinions are ground and burnished, the engaging edges of the teeth being chamfered.
Standard equipment of the chassis includes a speedo meter, front mudguards, eke tric lighting, horn and self starter, spare wheel and tool kit. The concessionaire is the International Harvester Co., of Great Britain, Ltd., Harvester House, 259, City Road, London, E.C,1. The price of the chassis is 1635 with the equipment specified, a recent reduction having been made.
In addition to the vehicle illustrated on this page, a front-entrance body to carry 24 persons has also been mounted -on a similar Chassis by Messrs. Strachans.