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).
Letter discussing scraper ring efficiency, piston collapse, and oil consumption in Bentley cars with Aerolite pistons.
| Identifier | ExFiles\Box 27a\1\ Scan229 | |
| Date | 31th January 1935 | |
| 4013 To Sr. - Paris: Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}13/KW.31.1.35. Dear Sr., Many thanks for Sr.1/Crn.26.1.35: Actually we find that the efficiency of the scraper ring largely depends on the unit pressure of the lands in contact with the cylinder and not on the area of holes drilled through the ring. At present we can run 15,000 miles on the Bentley in France with the Aerolite piston without our oil consumption varying at all. I think on the split skirt piston the variation in oil consumption is more likely to be due to the collapse of the piston than to the ring. However, I will go over our records and see how it is that we have decided on 4 holes rather than slots. Shall be interested to have any records of oil consumptions which you have, particularly on cars which have run 30,000 miles or so. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||