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).
Technical memorandum regarding the Goshawk II engine, discussing the gearbox, crankshaft damper, and the use of aluminium pistons.
| Identifier | ExFiles\Box 180\M1\1\ img085 | |
| Date | 1st October 1921 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to Sy. " " WOR.{Arthur Wormald - General Works Manager} " " DA.{Bernard Day - Chassis Design} " " BY.{R.W. Bailey - Chief Engineer} ORIGINAL RE "GOSHAWK II". X4219 GEAR BOX. X4247 As regards the noisy Hyatt roller bearing on the gear box, we are pleased to hear that you hope to cure this by making it slightly freer. It is quite likely that many ball bearings are fitted up too tightly, which would result in rumbling, and perhaps destroying themselves before they become free. At the same time it would be very disastrous to have slack in such bearings when used for supporting gearing shafts. CRANKSHAFT DAMPER. X4221 We understand that the period which requires damping is at a very high speed. This, therefore, only requires a very small flywheel in weight, but possibly with a fair amount of friction. The period will get worse with higher compressions, and it might be advisable to test various compressions. We should be content to lose a certain amount of power at the highest speed of, say, 3000 revs. PISTONS. X4224 As regards aluminium pistons, I think we should persevere with these, as they certainly should be lighter than cast iron, and less favourable to detonations. We find that they are fitted to such cars as the Essex, so that we think if they are a definite advantage they ought to be on a R.R. We do not regret having fitted them to the 40/50, as we are sure it has enabled that engine to do better than it could possibly have done with cast iron pistons. This specially refers to detonations which appear to be so bad with the present supply of petrol as to force us to lower compressions than are best for a good performance. (Contd.) | ||