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).
Test report on speedometer and rev-counter accuracy, with observations on car behaviour on a dynamometer.
| Identifier | ExFiles\Box 3\4\ 04-page270 | |
| Date | 1st November 1943 | |
| -4- Speedometer & Rev. Counter Check. 11/43 Axle. 5.30 x 18" India Tyres. 701 road wheel revs/mile. ROAD WHEEL REVS/MIN. SPEEDOMETER M.P.H. REV. COUNTER-R.P.M. CORRECT. ACTUAL. CORRECT. ACTUAL. 233.6 20 18.3 913.3 830 350.5 30 28.2 1371 1280 467.3 40 37.5 1827 1700 585 50 47.8 2285 2200 701 60 58 2740 2650 819 70 67.5 3202 3060 935 80 77.5 3656 3560 1053 90 - 4116 - Instrument temp. during above test 31°C. GENERAL BEHAVIOUR OF CAR ON DYNAMOMETER. Silver Ghost thermostat kept water temp. constant at 83°C. Engine oil pressure low - never exceeded 25 lbs/sq.in. Oil consumption appears good, but above 3000 R.P.M. a considerable amount of oil comes out of the exhaust. Exhaust system never gets red hot indicating low back pressure. Engine free from oil leaks. Gearbox oil leaks from breather hole in change speed tower after about 10 mins. running; also from servo drive. Oil temp. in gearbox reached maximum of 76°C after 1/4 hr. full throttle. 50% XXL, and 50% Whitmore's Compound used in gearbox during tests. | ||