Magneto timing for RR.F.XI.B. and F.XII.B. engines with a 7/1 compression ratio.
| Identifier | ExFiles\Box 33\4\ Scan114 | |
| Date | 14th June 1928 | |
| To BY. {R.W. Bailey - Chief Engineer} from Hs {Lord Ernest Hives - Chair} /VH. c. to RG. {Mr Rowledge} c. to EP. {G. Eric Platford - Chief Quality Engineer} Handwritten: X3835 X1770 Hs {Lord Ernest Hives - Chair} /VH/LG14.6.28. RR.F.XI.B. AND F.XII.B. MAGNETO TIMING. Handwritten: X1770 X3835 7/1 Compression ratio. To give a reasonable drop in r.p.m. on single ignition (one magneto switched off) with 7/1 compression engines, the timing of the magnetos should be :- A. {Mr Adams} side (inlet plugs) 38° B.T.D.C. B. side (exhaust plugs) 38° B.T.D.C. in the position corresponding to full throttle with the controls inter-connected. This assumes that there is practically no 'toggling over' of the magneto controls - a condition which at present exists on engines with long range magnetos. This makes the valve and magneto timing of a 7/1 comp: engine identical with that of a 6/1 comp: engine. Hs {Lord Ernest Hives - Chair} /V.Halliwell. | ||
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).