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).
The 15,000-mile running test of a 6.B.IV. Bentley engine unit N° 4 in France.
| Identifier | ExFiles\Box 83\2\ scan0056 | |
| Date | 31th May 1937 | |
| Swell. Hardy [symbol] Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/IMW{Ivan M. Waller - Head of Chateauroux}/2/JAB. 31.5.37. 200a To. Mr. Hs.{Lord Ernest Hives - Chair} from Rm{William Robotham - Chief Engineer}/GWH{George W. Hancock - Head Chateauroux}/IMW.{Ivan M. Waller - Head of Chateauroux} c.c. Hs.{Lord Ernest Hives - Chair} c.c. Hy.{Tom Haldenby - Plant Engineer} c.c. By.{R.W. Bailey - Chief Engineer} c.c. Der. c.c. MHC. c.c. MK.{R. E. B. Meade-King} c.c. Rm.{William Robotham - Chief Engineer} c.c. Mss. c.c. Geer. TESTS IN FRANCE. Specification of 6.B.IV. Bentley Unit N° 4. To. HPS{Horace Percy Smith - Experimental Factory Mgr}/CP.30.12.36 - 1.1.37. Report on 15,000 Miles Running. ENGINE UNIT N° 4. Performance was good but not outstanding. It was inferior in acceleration and maximum speed to Unit N° 3 in 3.B.IV. The engine was smooth and free from periods for the first 9,500 miles, after which it became steadily rougher and periods at 3700 r.p.m. were noticeable. There was no noticeable detonation. The engine gears were good standard for quietness. Oil pressure 90°c at 70 m.p.h. was 28 lbs/sq" at the start. This was increased to 40 lbs/sq" upon instructions received from Works. As the engine periods increased it fell to 35 lbs/sq". The sump was lagged in order to maintain higher oil temperatures, as under summer conditions. The normal maximum was 125°c, but on a few occasions 135°c was reached. these temperatures were also reached without the lagging. The effect of the lagging was that they were reached more frequently and maintained for longer periods. Oil pressure at maximum speed dropped from 40 to 35 lbs/sq" when the oil temperature rose above 120°c. Oil consumption was good under all conditions. the average for the mileage was 1650 m.p.g. During the first 2,500 miles, the consumption gradually improved from 700 m.p.g. to 1,700 m.p.g. The oil used was Castrol "XL". | ||