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).
Results of camshaft comparison tests on supercharged engines.
| Identifier | ExFiles\Box 43\3\ Scan221 | |
| Date | 3rd January 1929 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/VH. c. to BJ. SG.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} RG.{Mr Rowledge} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} Hs{Lord Ernest Hives - Chair}/VHl/LG3.1.29. +4003 CAMSHAFT COMPARISON TESTS -X1770 ON (1) Full supercharged engine. (2) Moderate supercharged engine. Tests have been completed (and officially observed by the A.I.D.) which shew the gain obtained by the use of long duration camshafts on S/C. engines. We give herewith the curves obtained for :- (1) Full S/C. engines. Comparative power curves at 10,500 ft. (2) M.{Mr Moon / Mr Moore} S/C. engines. Comparative power curves at 4000 ft. Comparative full throttle power figures at ground level. All these curves take the form of officially recognised comparisons and together with the results obtained on a normal 7/1 comp: engine (Hs{Lord Ernest Hives - Chair}2/LG16.10.26) justify the fitting of long duration camshafts to all F.{Mr Friese} engines in service. We give herewith the original std. valve timing compared with the timing for long duration camshafts :- Tappet clearance .030" Point on cycle. Std. Camshafts. Long Duration Camshafts. Inlet opens 8° A.T.D.C. 11° B.T.D.C. Inlet closes 38° A.B.D.C. 40° A.B.D.C. Exhaust opens 30° B.B.D.C. 48° B.B.D.C. Exhaust closes 8° A.T.D.C. 1° A.T.D.C. Hs{Lord Ernest Hives - Chair}/V.Halliwell. | ||