GENERAL CONSTRUCTION.

The Morris Ten-Four (Series "M") consists of a powerful O.H.V. engine built in unit construction with a four-speed synchromesh gearbox, mounted in an all - steel body of advanced design which entirely supersedes the normal chassis frame.
Transmission is by Spicer tubular propeller shaft with needle-type universal joints and the rear axle is of the three-quarter floating type with spiral bevel final reduction gears and differential. Suspension is by free acting semi-elliptic springs, with torsion bar stabiliser at the front, controlled by piston type hydraulic shock absorbers. The wheelbase is 7ft. 10in. and the track 4ft. 2in.

ENGINE.

The four-cylinder overhead valve engine of the Morris Ten-Four (Series "M") possesses a bore of 63.5mm. (2.5in.) and a stroke of 90mm. (3.54in.), giving a cubic capacity of 1140c.c. (69.57 cubic in.) and a rating of 9.99h.p.
The cylinders are cast in one with the skirt of the crankcase, which is liberally reinforced with internal webs to provide a structure of great strength and rigidity. The crankshaft is of the counterbalanced type with three large bearings ensuring freedom from vibration. Every crankshaft is carefully balanced to very close limits and the bearings have steel backed white metal liners. The connecting rods are of steel with full-ring steel-backed replaceable white metal bearing liners. They are carefully balanced individually and the complete assemblies of connecting rods and pistons are equalised in weight to within .2oz. as in best aero engine practice. The Pistons are of low expansion aluminium alloy and they are fitted with four rings - two compression and two oil control. The pistons are tin-coated to ensure freedom from pick-up, and have split skirts. The overhead valves are push-rod operated from a three-bearing camshaft situated in the upper portion of the crankcase. The camshaft is driven by a silent duplex roller chain which provides trouble-free drive possessing a very long life. Hollow chill cast tappets are fitted. Valve adjustment is by adjustable screws on the valve rockers.
An important feature of the induction system is the combined air cleaner and silencer which also collects all fumes from the upper part of the engine, so that they are prevented from finding their way into the car interior. In addition there is a large breather pipe discharging well below the body which ensures perfect crankcase ventilation and avoids condensation. The engine is mounted on the body by floating rubber connections which effectively damp out the last trace of engine vibration, and the one piece exhaust system is also flexibly mounted.

SYNCROMESH GEARBOX

The four-speed gearbox is provide with synchromesh engagement for second, third and fourth gears,, which are of the silent elliptical type. The gearbox is fitted with an accessible filling orifice and a dipstick oil level indicator. The gear ratios are : 1st - 20.087, 2nd - 11.849, 3rd - 7.929, 4th 5.286, reverse 20.087.

LUBRICATION SYSTEM

A large spur gear pump driven by helical gears from the camshaft supplies oil under pressure to all main and big end bearings, camshaft bearings and overhead valve gear. The delivery from the oil pump is sufficiently large to ensure adequate lubrication even when considerable bearing wear had taken place.
The oil intake in the sump is protected by a metal shield and is provided with a cylindrical gauze filter. The oil is further filtered before circulation by an external oil filter of "throw-away" type. The pump is fitted with a non-adjustable relief valve, and the relief valve for the external oil filter is also incorporated in the pump. Special provision has been made to guard against loss of oil past the valve gear. The undercarriage is lubricated by high-pressure oil gun and accessibly located nipples.

COOLING SYSTEM

The cooling water is circulated by a centrifugal water impeller with double ball races and special carbon ring leak-proof sealing gland. It is driven by a belt from the crankshaft and discharges into a special distribution duct cast in the cylinder block which ensures even cooling. An extension of the pump spindle carries the cooling fan. Cooling is further controlled by a thermostat in the water outlet pipe which ensures rapid warming up and the maintenance of the correct working temperature at all times automatically, therefore improving performance and lengthening the useful life of the engine.

CARBURATION

An S.U. automatic piston-type carburettor with adequate control over mixture strength for easy staring supplies the working mixture. The mixture control is conveniently mounted on the facia board and is interconnected with the throttle control so that the correct throttle opening for slow running when cold is obtained automatically. The carburettor is provided with an efficient air cleaner and silencer, while an intake balance pipe improves distribution, increases the power output and facilitate starting. Particular attention has been given to the carburetion system with a view of giving maximum economy without the sacrifice of performance. The induction manifold is provided with an adequate "hot-spot" and the fuel feed is by S.U. automatic electric pressure petrol pump.

PETROL TANK

The petrol tank is mounted at the rear of the chassis and has a capacity of 7 gallons. It's contents are clearly indicated by and electrically operated gauge on the facia board and the filler is fitted with a special anti surging device and large vent to facilitate rapid filling.

TRANSMISSION

A single-plate dry clutch with cushion hub and single point adjustment provides smooth engagement with light action and the minimum attention' A spicer tubular propeller shaft with needle-type universal joints at each end serves to transmit the drive to the rear axle.

REAR AXLE

The rear axle is of the three-quarter floating type with a one piece banjo and silent bevel final reduction gears. All pinion and crown wheel bearings are of the taper roller type, which ensures long life and silence of operation. A scientific system of selection and assembly is employed to ensure maximum efficiency.

FOUR-WHEEL BRAKES

Fully compensated foot brakes of the internally expanding type, operated by the Lockheed hydraulic system, ensure the maximum possible braking efficiency. Their certainty of action is maintained under all conditions and there are no bearing to wear or need lubrication, or cables to stretch. The brake-shoes are of steel with high-efficiency linings. The hand brake is provided with adjustment from the drivers seat and operates on the rear wheels by cables totally enclosed in grease-packed conduits. Special provision has been made to protect the brake shoes against the weather.

STEERING

The steering gear is of the Bishop cam type and careful design of all the steering components has resulted in exceptionally light steering which is particularly situated to lady drivers. In spite of the lightness of the steering it is precise in action and free from any tendency to wander. Track rod joints are of the self-adjusting type, eliminating all backlash. The steering is particularly free from road shock reaction.