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).
Table of engine compression measurements at different speeds for chassis No. 935.
| Identifier | ExFiles\Box 19\7\ Scan023 | |
| Date | 23th July 1920 | |
| H.R. 288a (100 T) R.H. sg.{Arthur F. Sidgreaves - MD} 23-7-20: G 2769 X.790. Compressions at varying engine speeds. Takes on chassis No. 935 (4 1/4" stroke) with non-return valve tackle, fixed in ignition plug hole and Mr. Ellis' large gauge. Speed revs. Lbs. compression. 660 73 1000 70 1200 70 1250 62 1800 50 | ||