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).
Crankcase blowby figures, oil consumption, and a comparison of piston rings.
| Identifier | ExFiles\Box 148\1\ scan0213 | |
| Date | 27th November 1939 | |
| -3- RM{William Robotham - Chief Engineer}/CFC.11/JH.27.11.39. Crankcase blowby figures, apparently are of little value in relationship to oil consumption figures. A noteworthy feature of the Hepworth & Grandage ring is the machined away portion to form the 'L' section, This is approximately half that of our tin plated 'L' section ring, yet it gives satisfactory results. We have a set of our rings machined in a similar manner, fitted in B.80 No.7 unit. This engine is running in chassis 33.G.VII. Rm{William Robotham - Chief Engineer}/C.F. Caisley. Rm{William Robotham - Chief Engineer}'s. observation. These tests should certainly be repeated at minimum throttle opening to maintain 4000 r.p.m. as a large part of road running is carried out with the throttle shut. Rm.{William Robotham - Chief Engineer} | ||