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).
Performance curves for a Bensport J.I. Unit C.9 engine, testing various exhaust system modifications.
| Identifier | ExFiles\Box 155\1\ scan0066 | |
| Date | 28th January 1933 | |
| BENSPORT J.I. UNIT C.9 RM.{William Robotham - Chief Engineer}B2 COMP.RATIO 6:3:1. CYL. HEAD STANDARD E.56604. CAMSHAFT E.59139 (113 1/2°) 2 - 1.375" S.U. CARBS: ON SPECIAL PIPE BETWEEN CYLS: 1&2. 5&6. BALANCED WITH SPECIAL 1.000" RESTN. ① COMPLETE EXHAUST SILENCER SYSTEM. ② SWAN-NECK REMOVED. ③ REAR CHAMBER REMOVED. ④ OPEN EXHAUST. ⑤ C.O. FITTED HERE. THIS CYL. HEAD HAD NOT BEEN TREPANNED ROUND THE INLET VALVE. SWAN NECK REAR CHAMBER. FRONT CHAMBER. B.H.P. B.M.E.P. R.P.M. C.T.S. | ||