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).
Telephone message discussing the disappointing lack of expected engine performance improvements on a 20 HP model.
| Identifier | ExFiles\Box 5a\5\ 05-page205 | |
| Date | 25th April 1929 | |
| RECEIVED OVER TELEPHONE 25.4.29. V5771 FROM R.{Sir Henry Royce} TO BY.{R.W. Bailey - Chief Engineer} I am somewhat surprised that no definite improvement was found between London Trials and G.4. One can only think there is some quite remarkable advantage in both power and smoothness between a well running chassis and a somewhat new one, that is the production 20 HP. do better horse power after being in use some time, but we do not get much from the head alone. It was only thought to have the advantage of less possibility to detonations, and so enable a possible increase in compression ratio. We have not, I believe, increased the compression, but rather let the engine go for. We have with the new head got such an improved inlet and exhaust system that unless we have done something wrongly we expected the engine to fill up better and to better distribution that more horse power would be obtained, and also that we should get two other improvements, that is good cold distribution starting from cold, and also no explosions in the exhaust. Moreover I have before me Mr. Hives's memo Hs{Lord Ernest Hives - Chair}/ACL/ko.28.3.29. giving at 2000 revs. an increase of over 11 HP. in 40, really 26%. It cannot be possible that this has no effect and difficult to believe that it has been massed by the difference of free running engines. Moreover I cannot believe that Hs.{Lord Ernest Hives - Chair} and EP.{G. Eric Platford - Chief Quality Engineer} would leave Derby with a car that had no more H.P. on the test bed or dynamometer than the present standard 20 HP. Perhaps in addition to the free running the body was different or had greater windage, or the engine revs. were so high that the valves were jumping. Will E.{Mr Elliott - Chief Engineer} telephone this message to Derby, and wire me some results. We cannot also understand a rougher engine or more power and less mechanically tight to cause compression ratio same. R.{Sir Henry Royce} | ||