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).
Ignition advance test results for Goshawk and 40/50 engines.
| Identifier | ExFiles\Box 37\1\ scan 226 | |
| Date | 14th April 1921 | |
| x3949 R R (M) (a) T/S H.{Arthur M. Hanbury - Head Complaints} 936. 19-4-21; G 3008 To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to C.J. c. to B.V. c. to E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} Hs{Lord Ernest Hives - Chair}5/LG14.4.21. x 699 [crossed out] x3949 IGNITION ADVANCE ON 40/50 AND GOSHAWK ENGINES. X928 We have taken tests on the Test Bench to find the range of ignition required on the Goshawk and 40/50 engines. The figures are as follows:- Goshawk run on test bench. Bosch Magneto. R.P.M. Minimum Advance for full power. Maximum Advance for full power. 3000 39º on flywheel 50º on flywheel. 2500 38º 48º 2000 33º 45º 1500 30º 42º 1000 25º 39º 500 20º 37º 40/50 engine - high compression. Battery ignition firing over inlet valves. R.P.M. Minimum. Maximum. 2250 30º on flywheel 52º on flywheel. 2000 29º 48º 1750 27º 43º 1500 24º 39º 1250 22º 34º 1000 18º 30º 750 13º 25º 500 9º 21º 400 8º 18º It will be seen that the Goshawk requires more advance at low speeds. The only reason we can give for this is that with the 40/50 engine we get detonations at low speeds. We are arranging a scheme(I saw in use at the Bosch Factory) in order to read the point at which Contd. | ||