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).
Pinning of rings and balancing of a ram piston for a 40/50 HP chassis.
| Identifier | WestWitteringFiles\D\November1919\ Scan3 | |
| Date | 7th November 1919 | |
| TO BA. from E.{Mr Elliott - Chief Engineer} Copy to CJ. (Strikethrough) " " BN.{W.O. Bentley / Mr Barrington} (Strikethrough) " " EH. (Strikethrough) " " EFC. ORIGINAL. X.3715. E1/C7/11/19. RE RAM PISTON - 40/50 H.P. CHASSIS. With reference to the pinning of the rings on the ram piston LeC.1152 for the chassis, the top ring was shown pinned on the power side with a view to avoiding exposing the ring joint. This had the effect of bringing the joint in the oil scraper ring on to the non-power side, and the danger of over-oiling due to this was afterwards taken up with Mr. Royce, when he decided that the top and third rings should be pinned on the non-power side and the second and scraper on the power side. Mr. Royce has, I believe, already written to you about this. With reference to balancing the piston, Mr. Royce thinks we may have some holes in the piston wall on the ram side. Countering the weight of the ram by this method provides a lighter piston. E.{Mr Elliott - Chief Engineer} | ||