Performance graph showing BHP and BMEP against RPM for a specific engine configuration with two different timing settings.
| Identifier | ExFiles\Box 155\1\ scan0067 | |
| Date | 28th January 1933 | |
| UNIT C.9 J1 HEAD BENSPORTCodename for 3 1/2-litre Bentley J1. C.9 RM {William Robotham - Chief Engineer} 83 JAN. 28/33 COMP. RATIO 6.3:1. CAMSHAFT E.59139 (13 1/2°) CYL HEAD: STANDARD E 56604. 2 1.375 SU CARBS ON SPECIAL PIPE BETWEEN 1 & 2 5 & 6 CYLS. BALANCED WITH SPECIAL 1.00" RESTN. ① EARLY TIMING ② LATE TIMING B H P B.M.E.P. R.P.M. C.T.S Timing Diagram 1 (Early Timing): T.D.C. 10.5° 54.3° 45.5° B.D.C. Timing Diagram 2 (Late Timing): T.D.C. 3.5° 65° 54.3° 50.7° B.D.C. TAPPETS AT .020 THIS CYL HEAD HAD NOT BEEN TREPANNED ROUND THE INLET VALVE. | ||
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).