Comparing the pistons and compression ratios of the Hawk-Northcliffe and 40/50 HP models.
| Identifier | WestWitteringFiles\J\January1923\ Scan3 | |
| Date | 1st January 1923 | |
| ORIGINAL. To R. {Sir Henry Royce} from Hs. {Lord Ernest Hives - Chair} Hs {Lord Ernest Hives - Chair} 4/LG1.1.23. X3408 X3773 X790 PISTONS ON "HAWK(Aero Engine)-NORTHCLIFFE". The pistons on the above chassis are similar in design to the 40/50 HP. They are the split type with 4 rings. The rings are pinned in our standard manner at right angles to the gudgeon pin and alternately on each side of the piston. The compression ratio on the Hawk(Aero Engine)-Northcliffe is much higher than we use on the 40/50. The Hawk(Aero Engine) Northcliffe is 4.8 to 1 - 6.EX Car which is at W.W. and which has the present standard 40/50 HP. compression is 3.9 to 1. Hs. {Lord Ernest Hives - Chair} | ||
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).