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).
Design of a 40/50 HP aluminium piston with a 2' diameter anti-knocking ram.
| Identifier | WestWitteringFiles\D\October1919\ Scan27 | |
| Date | 1st October 1919 | |
| To DR. from E.{Mr Elliott - Chief Engineer} Copy to CJ. " " EPC. ORIGINAL. E5/G30/10/19. 2 RE 40/50 H.P. PISTON. X.3715 We send you herewith drawing No. LeC.1152 shewing an aluminium piston fitted with a 2" diameter anti-knocking ram. You will notice that the piston is of the duplex pattern, and has a 4" diameter trunk. The ram is prevented from rotating by a flatted taper pin driven into the piston casting, similar to the pin we use for preventing the rings from rotating. The ram piston is shewn in its simplest form, with oil pressure on all the time. The gudgeon pin is plugged at one end with a sheet metal pressing in steel which, after being forced in, is locked in place by reason of its edge being rolled into a groove in the bore of the piston pin. The other end of the piston pin is stopped by a removable aluminium plug. The plugs makes an oil joint on its head, which has a slow taper of 1 in 8, and is locked in position by the gudgeon pin locking screw, which passes through one of the two cross holes drilled in the plug. As Mr. Royce does not wish the ram to run out of the cylinder bore more than is absolutely necessary, he would like you to make the piston to suit the lowest compression desired, so as to avoid using a compression plate for the purpose of raising the cylinders. Pistons of high compression should also, of course, be made to suit a model intended for use with open bodies. (Contd.) | ||