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).
Bentley B.35.KU oil consumption tests at high speeds on Brooklands track.
| Identifier | ExFiles\Box 131\4\ scan0368 | |
| Date | 16th July 1937 | |
| 11/13 also 1220. Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} Rm.{William Robotham - Chief Engineer} MX.{John H Maddocks - Chief Proving Officer} W/P - SR. Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}2/R.16.7.37. BENTLEY OIL CONSUMPTION. B.35.KU. We have been carrying out tests on the Brooklands' track with B.35.KU (Paris New Trials car) to ascertain the oil consumption at high speeds. The test has proved that driving round the track at a high speed with no over-run the oil consumption is very little higher than a much lower average speed on the road. The average speed of 45 M.P.H. from Derby to Brooklands gave an oil consumption of 1,500 M.P.G. An average speed of 72 M.P.H. for 82 miles on the track gave an oil consumption of 1354 M.P.G. The temperature of the oil averaged 128°C, the pressure averaging 20 lbs after the first few laps. We seized the dynamo drive pinion on the bronze bearing during further tests due to increasing the main oil pressure by increasing the strength of the release spring. We point this out as frequently in service the release valve spring is strengthened up, to increase the main pressure which starves the rocker shaft, and practically no oil gets to the dynamo drive pinion shaft. We have a large number of cars on the road running under this condition, and we are fortunate that the dynamo pinion has not seized. ----------- The test has proved that the present production of Bentleys with the new type piston and scraper rings has improved the oil consumption considerably, which should be satisfactory for the Continent. We shall carry out further tests at Brooklands to find under what running conditions we can reproduce road work. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} | ||