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 improvements, focusing on Kestrel development, hardened crankshafts, and the .475 reduction gear.
| Identifier | ExFiles\Box 179b\2\ img090 | |
| Date | 11th November 1932 guessed | |
| -6- Improvements could be made to them, but this will always apply to whatever type of rod we use. The present rods run satisfactorily on Kestrel development between 1100 and 1200 HP. so that they cannot be lightly discarded. Re. hardened crankshafts. We are now accumulating considerable experience with these crankshafts. We have run an official Type Test satisfactorily and we have got them fitted to most of our development engines. At the present time we cannot get much enthusiasm from the A.I.D. on the hardened shaft itself because our present crankshafts are giving wonderful service and on the engines which have come in after 500 hours the wear has not been sufficient to justify them being re-ground. The other features which gives us a certain amount of difficulty is the .475 reduction gear. We have got to accept that this gear is not sufficiently reliable both on bench tests and in service. As we increase our engine speeds this gear will be required more than at present. We understand Mr. Ellor is issuing an improved design which should give us a definite improvement. The general position therefore is that all the troubles on the engine are well in hand. We are in a position to increase the revs and the H.P. with reliability. The criticism against the two-piece cylinder block as regards weight can be justified by the increase in performance and these should reduce our cylinder trouble. Our bearings are being looked after by the use of Kelmet and hardened shaft. Designs are well in hand for the improved .475 reduction gear. TMB. | ||