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).
Recommendation to adopt slotted scraper piston rings for the Phantom III chassis.
| Identifier | ExFiles\Box 94\5\ scan0107 | |
| Date | 9th December 1935 | |
| +336 Rm{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} from Mx.{John H Maddocks - Chief Proving Officer} Mx{John H Maddocks - Chief Proving Officer}22/T9.12.35. RE. PHANTOM III PISTON RINGS The three Phantom III Cars which have been used for demonstration purposes were fitted by us with slotted scraper rings. These cars have now run a considerable mileage. We believe the slotted ring has been a definite advantage in controlling the amount of oil passing the pistons. The slotted ring is better than the drilled type as the latter gets choked up with carbon and becomes ineffective. The slotted rings we used were taken from Bentley aerolite pistons and had to be reduced .005 in thickness to suit the Phantom III pistons. We recommend the adoption of the slotted scraper ring for production. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} is in agreement. If you agree, will you please take the necessary action as the supplies of the drilled type are coming into the Works for use on the first lot of Phantom III Chassis now being built. Mx{John H Maddocks - Chief Proving Officer} | ||