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).
Power curve comparison between a long duration and a standard camshaft.
| Identifier | ExFiles\Box 43\3\ Scan202 | |
| Date | 12th October 1928 | |
| POWER CURVE WITH LONG DURN. CAMSHAFT. COMPARISON WITH STANDARD CAMSHAFT. ROLLS ROYCE FXI ENGINE N° SLA. TA9. COMPRESSION RATIO = 7 : 1 GEAR RATIO = .552. MAGNETO TIMING = 40° BEFORE T.D.C. FUEL USED = T.E.L. DATE OF TEST 9/10-10-28 CURVES CORRECTED TO N.T.P. BRAKE HORSE POWER. RPM OF ENGINE. SP.{Mr Spinney} CONS. (PTS/BHP/HR). LONG DURATION CAMSHAFT. STANDARD CAMSHAFT. SPECIFIC CONSUMPTION. VALVE TIMINGS (.020 TAPPET CLEARANCE) | | LONG DURN CAMSHAFT | STD. CAMSHAFT | |---|---|---| | INLET OPENS | 12.5° BEFORE TDC | 8° AFTER TDC | | INLET CLOSES | 46° AFTER BDC | 46° AFTER BDC | | EXHAUST OPENS | 51° BEFORE BDC | 38° BEFORE BDC | | EXHAUST CLOSES | 5° AFTER TDC | 13° AFTER TDC | Signature: A.F. Sidgreaves Stamp: A.I.D. Date: 13-10-28 | ||