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).
Modifications to seven-ringed Zephyr type chassis pistons.
| Identifier | Morton\M11\ img016 | |
| Date | 2nd October 1916 | |
| R.R. 235 A (400 T) (S.C. 586. 15-2-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546. To By from E.{Mr Elliott - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} c. to Clk. COPY. COPY. RE - CHASSIS PISTONS. E2/W21016. 2/10/16. With reference to the seven-ringed Zephyr type pistons, will you please arrange in accordance with Mr. Royce's instructions to have this piston made with, and without some skirt below the scraper ring. You will note that the piston at present is shorter than the trunk type, owing to the fact that we have put the scraper ring in the lowest possible position (where it will not run out of the mouth of the cylinder) and cut off all the remaining skirt below it. The alternative type of piston mentioned above should have the scraper ring in the same position, relative to the piston rings, but should have that piece of skirt added for the sake of the increased bearing surface preventing piston knocks. In the larger type of piston sent to you, you will remember that only two rings were pinned, these two being close to the bottom (excepting the scraper ring), that is to say numbers five and six rings numbering from the top. Would you please arrange in accordance with Mr. Royce's wish to pin rings numbers four and six instead of five and six. E.{Mr Elliott - Chief Engineer} 369 9 | ||