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).
Balance weight schemes for the 25HP engine, covering production, experimental, and new shaft designs.
| Identifier | ExFiles\Box 103\3\ scan0091 | |
| Date | 28th August 1931 | |
| HS.{Lord Ernest Hives - Chair} ) FROM R.{Sir Henry Royce} BY.{R.W. Bailey - Chief Engineer} ) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} X5010 RL/M28.8.31. 25HP. - BALANCE WEIGHTS. (1) PRODUCTION. Existing shafts which were not prepared for balance weights can only have the 8/6 scheme this being the only one that can be used without cutting dangerously into the crank webs, as is the case with the 12/8 scheme with half weights at 30°. (2) EXPERIMENTAL. One or two engines can be fitted with the 12/8 scheme temporarily for our own use, and to find if this is as good as 8/6. (3) NEW SHAFT. The dies should stand over until (2) has been tested, but considering that we now have a good scheme for production there is very little doubt that this arrangement will be adopted and if at all passable, is known to be theoretically superior for relieving the bearings of load, and the crankcase of stresses and deflection. (4) TAIL BEARING. So that only a moderate balance weight can be used, it will be advisable to adopt the tail bearing and thin web flywheel which we have arranged to try. (5) My impression is that this was on the car at Brooklands on 26.8.31. which we thought also had an ignition coil with external winding and no ballast resistance. It is important to know if such a coil cures low speed miss-fires, as I have recently imagined. Please send me one. R.{Sir Henry Royce} | ||