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 design, fuel systems, and key mechanical improvements like the gearbox and crankshaft.
| Identifier | ExFiles\Box 179b\1\ img042 | |
| Date | 3rd September 1932 | |
| 20. FROM R.{Sir Henry Royce} ORIGINAL. R2/M3.9.32. 20 C. to WGR. HS.{Lord Ernest Hives - Chair} BY.{R.W. Bailey - Chief Engineer} re. THE CAR YOU HAD IN FRANCE AUGUST 1932. C. to FH. E.{Mr Elliott - Chief Engineer} BA. J.{Mr Johnson W.M.} I. HEAD, ETC. X5770 There has never been any reason why this head should have made a coarser engine than the 'China' head, rather the other way about, because the distribution is more perfect, and therefore the impulses should be more regular. It has however always been made with a higher compression ratio, which has never been tolerable until the more flexible mounting of the engine was adopted. As regards the electrical petrol pumps on this car they were never intended for anything except temporary convenience. They were never suggested by me, or from WW., in fact, I do not favour any electrical fittings in preference to mechanical ones, and this especially applies also to the petrol pump and gauge. Regarding the SU. carburetters I have very little practical experience with these in their latest form, but have given the Works from time to time my theoretical reasons why they should not be fitted to RR. cars. In the past they have not given very satisfactory results, due I believe to the wear of the needle etc, and they have also a moving spindle below the petrol level in connection with the regulation and starting control, which I think very dangerous, being very liable to drop petrol. Referring to recent improvements in the performances of our cars it should be remembered that our old characteristics are far more valuable to the ordinary user than a higher maximum speed, the extra HP. of the engine at high speeds being very rarely available to the driver because the engine is so rarely running at these high speeds. There have been however two or three things introduced which are of the utmost value and importance, namely, the synchro mesh gearbox, and the balance weights on the crankshaft. For the former we have to thank the Americans, and for the latter ourselves. It will be remembered that the early Silver Ghost had balance weights fitted, but the crankshaft was hardly stiff enough to prevent these doing more harm than good. We also at that time had not such a light arrangement as our RR. 8 weight, 6 unit scheme. The beauty of these balance weights is that they keep the flywheel at the rear and the slipper wheel at the front from periodic vibrations, which I was very anxious to cure during the trouble with your 'fuss and roar' complaints. (1) | ||