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 test report discussing ignition, spark plugs, running speed, vibrations, and camshafts.
| Identifier | ExFiles\Box 179\2\ img226 | |
| Date | 10th February 1932 | |
| -2- Hs{Lord Ernest Hives - Chair}/Mths.{Reg Matthews}3/MJ.10.2.32. Cont'd.{John DeLooze - Company Secretary} IGNITION. The ignition system is Bosch Coil type and distributor has double contact breaker. According to the Handbook automatic ignition advance device operates above 1000 RPM. The automatic advance device appears to be correct at all speeds, no increase in power could be gotten at any speed when hand control was put in full advance position. The ignition timing with control in this position is 19.5° before T.D.C. Tests to determine the spark advance at all speeds have not been tried successfully, efforts were made to rig up the apparatus at the end of the dynamometer shaft but failed owing to the clutch slipping slightly and allowing the spark indicator finger to creep, no reliable figures were taken. The most convenient place on the engine for these tests appears to be the tachometer drive at end of the exhaust camshaft and when the engine is next on the bed we propose rigging up a suitable indicator at this position. The Sparking plugs fitted in the engine when received on the test bed were Champion R.3 type but trouble was experience with these plugs pre-igniting at high speeds. K.L.G. K1 plugs were fitted later and these plugs certainly stood up to high speed running better than the Champion plugs but did not entirely overcome the trouble of pre-ignition they were definitely better for starting purposes. Lodge A.40 plugs were eventually used and no trouble was experienced except in the matter of starting in which case they are not so good as K.L.G. K.1. SLOW RUNNING. The minimum slow speed running is in region of 400 RPM. and is very erratic at that speed. VIBRATIONS. The engine appeared to be very smooth at all speeds except 3750 RPM. at which speed the whole bed vibrated. This vibration may, in some measure, be attributed to the engine but it is quite probable that it was also magnified by the dynamometer which has about reached the limit of its reliability. By the time the engine is next on the bed a new dynamometer and silencer will have been rigged up so that we shall then be able to state at speeds the crankshaft vibrations are. VALVES AND CAMSHAFTS. The engine has two separate camshafts driven by bevel gear from the rear end of the crankshaft. The cams. work | ||