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).
Investigations and recommendations concerning engine oil consumption and cylinder wear.
| Identifier | ExFiles\Box 132\4\ scan0094 | |
| Date | 19th October 1937 | |
| -2- Oil Consumption - cont'd.{John DeLooze - Company Secretary} being that the ring is not square in the groove due to its natural twist when closed and vibration is therefore damped out due to friction of ring in groove. (9) With existing oil supply at low speeds it is useless to aim at getting oil consumption in region of 3000 - 4000 m.p.g., a consumption of 2000 m.p.g. under normal conditions and 1,500 - 2000 m.p.g. under fast driving conditions is what we must expect. Recommendations for improving oil consumption. (a) Rings designed with flutter speed above 4500 r.p.m. (b) Taper faced rings for quick bedding, a ring to our requirements has already been drawn and is to be used on Wraith and Bentley experimental cars. Drawing No. M.W.V.1425. (c) Cylinder with least possible distortion, this should not be more than .0005 with cylinder head bolted to cylinder block. Cylinder Wear. (1) Our investigations show that ring pressure has an effect on bore wear. (2) Ring flutter as far as we know at present does not effect bore wear. (3) There is no appreciable difference in wear with cylinders of 270 Brinell and 400 Brinell. (4) Piston clearance has an effect on bore wear. (5) Majority of wear appears to be due to corrosion coupled with insufficient lubrication at low speeds, and not due to abrasion. (6) Nickel addition to iron does not improve bore wear. | ||