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).
Improvements related to engine noise, exhaust boom, and smoothness on a 20/25 HP test car.
| Identifier | ExFiles\Box 5a\4\ 04-page014 | |
| Date | 20th January 1934 | |
| S/W. E.{Mr Elliott - Chief Engineer} c. to Sd.Cor. c. " Mr. HY.{Tom Haldenby - Plant Engineer} O.{Mr Oldham} HS{Lord Ernest Hives - Chair} x5860 Cx{Major Len W. Cox - Advertising Manager}1/KHS.1.34. Dictated 20.1.34 20/25 h.p. Next 10,000 Miles Test Car. R/Lid.{A. J. Lidsey}3/HPS.{Horace Percy Smith - Experimental Factory Mgr}1.34. I should like firstly to correct the impression that I was in any way suggesting that improvements as regards silencing our cars had been somewhat neglected by the Works, and I would like to state quite definitely that the question of neglect of that important subject never even entered my mind. It was of course difficult for me to appreciate from the very brief descriptions of improvements contained in R/Lid.{A. J. Lidsey}1/HPS.{Horace Percy Smith - Experimental Factory Mgr}1.34. that the changes recorded under items(8), (9) and (10) had for their sole object improvements in engine gear noise, as their description does not of course indicate that this is what is in your mind. It is very nice to know, of course, that these features will each contribute to more silent running. Again item (17), your enlargement on this feature which I have now read is particularly interesting from the point of view of exhaust boom, because the car that I referred to in my Cx{Major Len W. Cox - Advertising Manager}1/KHS.1.34. was particularly bad on booming, and EP{G. Eric Platford - Chief Quality Engineer} in his test of this car, which is now in his possession, confirms that it is a bad boomer. How much is caused by the body and how much by the chassis it is difficult at present to say, but the modification to which EP{G. Eric Platford - Chief Quality Engineer} refers concerning attention to floorboards has already been carried out on this car with very little improvement, so that if the exhaust system is a contributory cause then possibly the flexible silencer mounting is going to help us considerably in that respect. Item (18), this is not a noise that one hears when the car is being driven. Item (34), the larger balance weights we now understand have for their object smoother high speed performance. May we assume therefore from that that the Bentley type crankshaft also referred to in No.34 is the feature that will remove the 18 m.p.h. period? That period can be very troublesome in causing everything that can to rattle or buzz, particularly the change-speed lever and the knob in the top of it. Incidentally, whilst on this subject of smoothness and silence, I had the opportunity yesterday of driving the Essex Terraplane Saloon, and I was amazed to find how much smoother and more silent this car was as regards its engine than the 20/25. I also noticed that the Essex has the unit construction of engine (contd) | ||