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).
On aero engine performance, suggesting an increase in HP rating to maintain a competitive advantage for water-cooled engines.
| Identifier | ExFiles\Box 179b\2\ img087 | |
| Date | 11th November 1932 | |
| ORIGINAL X3993 To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to W. c. to ST.{Capt. P. R. Strong} c. to Rs.{Sir Henry Royce's Secretary} c. to LF. c. to E.{Mr Elliott - Chief Engineer} c. to SP.{Mr Spinney} c. to Lp.{Mr Lappin} Hs.{Lord Ernest Hives - Chair}1/W.11.11.32. AERO ENGINES. The HP. rating of our engines was fixed about four years ago. Since then they have not been increased. Recently our competitors as one would expect, have by means of improved machines increased B.H.P. and reduced drag to approximately equal our performance. It is recognised that there is always a prejudice against the water cooled engine and it must maintain a definite superiority of performance for it to hold its position. Fortunately we are in a very favourable position to increase our ratings sufficiently to put us well ahead again. We have already run approx. three Type Tests at 2200 R.P.M. normal revs. A further one is being run off at the present time. So that on the question of increase in revs. we consider we are reasonably safe. The new supercharger for Kestrel has given us what was anticipated - a very much more efficient blower which allows us to take bigger B.H.P out of the engine. Perhaps the most valuable information of all is that we now have the experience of hundreds of engines in service and of examining a number of engines which have run 500 hours in service without dismantling and we have fully supercharged engines which have run approximately 400 hours. We have kept a very accurate check of all the service troubles and complaints and there is no evidence that we have had a single failure which has been due to running at too high BHP. We have on | ||