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).
Engine specifications, valve timing, and performance test results for the Bensport C.10 unit.
| Identifier | ExFiles\Box 3\4\ 04-page249 | |
| Date | 24th March 1933 | |
| Y48836A 24.3.33 19.G.IV. - BENSPORT ENGINE (C.10 UNIT). Twin S.U. Carburetters. 6 x 19" tyres. 11/50 rear axle. Camshaft R.59139 - 113°. (60 m.p.h. = 3018 r.p.m.) Lightened flywheel Hs.{Lord Ernest Hives - Chair}932. Free exhaust. Compression ratio 6.3/1. Weight of car complete - 36 cwt 14 lbs. Valve Timing. .020" tappet clearance. No.1 Cyl. I.O. 1.5° B.T.D.C. E.O. 43.5° B.B.D.C. I.C. 52.5° A.B.D.C. E.C. 11° A.T.D.C. No.6 Cyl. I.O. T.D.C. E.O. 46.75° B.B.D.C. I.C. 52.5° A.B.D.C. E.C. 10° A.T.D.C. ----------- Performance Tests. (1) Ignition Timing 18° B.T.D.C. Ticknall Hill 55.6 secs. 55.8 secs. 55.4 secs. Pisterm Hill. 55 secs. 56 secs. (Detonates up to 32 m.p.h. water temp. at 80°C). (2) Ignition Timing 10.5° B.T.D.C. (5 notches down). Ticknall Hill. 56.2 secs. 55 secs. Pisterm Hill. 55.2 secs. 57.2 secs. (Detonates up to 22 m.p.h. water temp. at 80°C). N.B. Pisterm Hill test started at first gate on left past the old level crossing. Roads dry, no wind, - perfect conditions. ----------- | ||