From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Detailed specification sheet for a vehicle chassis, with handwritten annotations.
| Identifier | ExFiles\Box 90a\6\ Scan021 | |
| Date | 16th July 1936 guessed | |
| CHASSIS SPECIFICATION Handwritten note: If this is Standard what is the T.T. job producing. ENGINE. Six cylinder. 88.5 m/m bore. 120.64 m/m stroke. 4453 c.c. R.A.C. Rating 29.13 h.p. Tax £22-10-0. The engine [Handwritten note: gives 140 b.h.p. with Bentley Cyl. Hd.{Mr Hayward/Mr Huddy}] Cylinders are a monobloc casting having a cast iron detachable head, the latter being fitted with two valves per cylinder operated by push rods and rockers from the camshaft mounted in the crank case. Inlet and exhaust valves are interchangeable. Pistons are of special alloy fitted with three compression and two scraper rings. The crankshaft is mounted upon four large bearings in the top half of the crank case. Ignition is by magneto incorporating automatic advance and retard control, in conjunction with a lever on steering column. Two special S.U. carburettors which are synchronised and interconnected are fitted and a mixture control enables the engine to be readily started when cold. Petrol consumption varies according to conditions and speed, an average of 15-17 m.p.g. can be expected with normal driving. Lubrication is by pressure feed system. A gear pump delivers oil at approx. 30 to 40 pounds per square inch to all crankshaft bearings and valve operating gear. Pressure may be adjusted by a special by-pass valve. Oil capacity of the engine sump is 2¼ gallons. Cooling is provided by pump circulating water through an efficient radiator, with thermostatically controlled shutters. The flexible engine mounting insulates the coachwork from noise vibration. ELECTRICAL EQUIPMENT. A 12-volt system is supplied in conjunction with a constant voltage dynamo which is positively driven, and maintains a charging rate in accordance with the current discharged from the batteries. The two special batteries have a capacity of 90 ampere hour. The electric starter motor is a separate unit controlled by a switch on the instrument panel. Batteries and all electrical junction and fuse boxes are mounted in a most accessible position forward of the dashboard. CLUTCH. The clutch is of single dry plate type, automatically lubricated. GEARBOX. A separate unit and synchromesh type. Four forward speeds and reverse are provided. Gearbox overall ratios 3.66 top; 4.76 third; 6.15 second; 11.49 first. The gearbox has an oil capacity of 6¾ pints. The synchromesh mechanism enables the driver to change the gears most frequently used swiftly and without double declutching. The gears are quiet in operation. A right-hand gate change is fitted with gear lever conveniently placed in relation to the driver's seat and steering column. TRANSMISSION. Drive from the gearbox to the rear axle is by open propeller shaft having needle bearing universal joints at both ends enclosed in oil tight casings. FRONT AXLE. Of H Section alloy steel. Steering pivots are of large dimension. The hubs are mounted on adjustable roller bearings. REAR AXLE. The rear axle is of semi-floating type, the drive being through silent spiral bevel and crown wheel. The reduction ratio of the final drive is 3.66 to 1. Oil capacity 3 pints. A very accessible draining tap to axle casing is provided. | ||