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 detailing modifications to a vacuum pump for a super sports engine.
| Identifier | WestWitteringFiles\S\September1928-October1928\ Scan059 | |
| Date | 1st September 1928 | |
| V413. ALUMINIUM WASHER .187 THICK UNDER CYLINDER CAP TO KEEP COMPRESSION RATIO APPROX. SAME. BRASS DISC .200 THICK SWEATED TO PISTON TOP TO PREVENT PRESSURE PORT BEING UNCOVERED WHEN PISTON IS AT BOTTOM OF STROKE. SUCTION PORT SWEATED UP AND RE-CUT .200 LOWER DOWN CYLINDER BORE. PISTON SHEWN AT BOTTOM OF STROKE. SCALE 1/1. MODIFICATION TO VACUUM PUMP. (SUPER SPORTS ENGINE). JHP 1-9-28 | ||