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).
Technical memorandum comparing the pistons and compression ratio of the 'Hawk-Northcliffe' chassis with the standard 40/50 HP model.
| Identifier | ExFiles\Box 41\1\ Scan072 | |
| Date | 1st January 1923 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} X3773 He4/LCl.1.23. PISTONS ON "HAWK-NORTHCLIFFE". X3408 X3773 X790 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-Northcliffe is much higher than we use on the 40/50. The Hawk Northcliffe is 4.8 to 1 - 6.KX 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} | ||