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).
Graph showing the effect of increasing clearance around the inlet valve on engine performance.
| Identifier | ExFiles\Box 102\5\ scan0095 | |
| Date | 5th October 1931 guessed | |
| EFFECT OF INCREASING CLEARANCE ROUND INLET VALVE JAPAN OPEN EXHAUST 112º CAMSHAFT E.55640 .344 VALVE LIFT 2 CLAUDELS 26 M/M CHOKES RAMMING PIPES COMPRESSION RATIO 5.35 Top Graph: VALVE LIFT .344 SOLID LINE: MIN. CLEARANCE ROUND INLET VALVE 225" DASHED LINE: MIN. CLEARANCE ROUND INLET VALVE .108" SEE SKETCH .013 CLCE. Circular Diagram: IN, EX, 40, 55, 4.6, 2 Bottom Graph: AS ABOVE BUT .395 VALVE LIFT Axes: B.H.P M.E.P. LBS/SQ' R P M | ||