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).
15,000-mile test car report for a Bentley.
| Identifier | ExFiles\Box 83\2\ scan0183 | |
| Date | 21th January 1938 | |
| COPY FOR FILES. 21st. January 1938. 200a o.B.IV - BENTLEY. 15,000 MILES TEST CAR. This car has covered 791 miles since fitting the new overdrive gearbox. The general performance is satisfactory. The times on Ticknall hill are direct 49.5 secs, overdrive 54.5 secs. Normal times for standard and other Bentleys are between these two figures. Engine. Noticeably smoother with standard deturbulated cylinder head and free from detonation . The period at 2500 r.p.m. has gone since attending to the crankshaft damper, but there is now a bad period at 3300 r.p.m. which has been demonstrated to Rm{William Robotham - Chief Engineer}/Gry.{Shadwell Grylls} The tappets are better than standard with the silent camshaft, but isolated ones still come up noisy on occasions. There is a thrash period from the engine gears at about 25 m.p.h. when accelerating. Clutch. Very good in all respects. Gear box. Syncromesh much better than previous over drive box and up to Bentley standard. Gears quiet. No trouble. Propellor Shaft. Standard R.R. shaft without damper. No trouble. Rear Axle. Just audible on drive at 40 m.p.h. No noise on over-run noticeable. Brakes. Effective in action with light pedal pressure. Squeaks from fronts with Ferodo M.R.3 recieving investigation by Rm{William Robotham - Chief Engineer}/AFM.{Anthony F. Martindale} Suspension. Ride good for Bentley, in front and rear seats. May find damping insufficient on max. for continental conditions. Steering. Remains good. Chassis. Bad front wing and lamp movement, also steering column shake, receiving investigation. Cooling System. Warmed up to 80°C in seven minutes running light at 1000 r.p.m. Thermometer fluctuates rapidly from 78°C to 83°C at high road speeds, attributed to the action of the thermostat. Electrical Equipment. A.C. instruments fluctuate and cables are noisy, at low speed. | ||