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).
Blueprint of a modification to a vacuum pump piston for an S.S. Engine.
| Identifier | ExFiles\Box 64\1\ scan0042 | |
| Date | 27th February 1922 | |
| V641. FOR ALL OTHER DIMENSIONS SEE E78795. SECTION 'DD'. SECTION THRO' DD IS UNALTERED. .550 ±.5. .875 DIA. CUTTER. .900 ±5. .125 ±5. SCALE 1/1. MODIFICATION TO VACUUM PUMP PISTON. (S.S. ENGINE). AHP 27-2-22 | ||