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 plotting the results of power tests on a PII unit, comparing performance with an open exhaust versus a standard silencer system.
| Identifier | Morton\M19\ img200 | |
| Date | 4th June 1931 | |
| POWER TESTS ON PII UNIT. TWIN CARBS R.R. 1.400 DIA: CHOKES. R TYPE PHANTOM SHAFT 110° TIMING AS ON 4.6.31 4.9 COMP: RATIO HEAD WITH DOUBLE VALVE SPRINGS TAPPETS SET { EXHAUST .008, INLET .006 BAR. 758 M/M B.H.P. R.P.M. OPEN EXHAUST WITH STANDARD SILENCER SYSTEM FITTED | ||