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).
Different engine balancing weight schemes and their implications.
| Identifier | ExFiles\Box 14\2\ Scan104 | |
| Date | 20th March 1931 guessed | |
| (2) TSN's calculations shew now quickly the load changes with speed, slightly over 10% increase in speed putting up the bearing load 45%. This however must allow for bigger pins and big ends: speed alone would be nearer 24%. I do not mind which of the 2 schemes is used but something quick on test is needed. This 4 weight, plus 4 half weight scheme in my telegram could be forged on quite conveniently, which would be safer and might be cheaper. I am quite prepared to hear that my 2 half weights are not quite so efficient as TSN's 4., but as the saving is 1 unit in 4, it looks as if the end ones could be heavier and so make up for what is lost in balancing the couples in my 2. compared with TSN's 4. It is possible that aero engine work does not permit the 4 weight scheme originally suggested but that the car engine stroke being longer in proportion does allow it. If we can use 3 units in my scheme instead of 4, they can be 4 each, and it looks as if they were are, as I thought, more efficient as well as much more practical. I shall hope to receive a complete summary of the whole matter, which I hope TSN. will get from m.{Mr Moon / Mr Moore} BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} and all concerned. Personally I was so interested in this for the car work that I have only just realised that TSN. was mostly concerned with the aero engine aspect, which I fear was hardly to be considered, though highly desirable if the added weight is not prohibitive. R.{Sir Henry Royce} | ||