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).
Completed design of a 2250 cc Bensport Blower, comparing it with a standard No.10 blower.
| Identifier | ExFiles\Box 140\1\ scan0022 | |
| Date | 23th September 1932 | |
| N 201 To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Eor. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} re Bensport Blower. -------------------- Please find herewith a print of LeC.3196 showing completed design for the above. This blower as has previously been pointed out has been proportioned to suit the special conditions of the Bensport layout, having regard also to the requirements of the blower itself. This blower is of 2250 cc. capacity and is one inch shorter, and naturally of larger diameter than the No.10, 1860 cc. on which our tests have been made up to the present. This is all to the good as regards volumetric efficiency. At the same time we have spread the ports in the casing and holes in the rotor cage which feed the blower so that a further gain in this direction should result. We believe that the standard No.10. blower is bad in this respect, and that this bears some relation to the loss in adiabatic efficiency and to the high intake temperatures at speed shown on our curves. The Powerplus people admit that the ports on the No.10. were originally designed for a much shorter blower and they commend the design we propose. A print of LeC.3216 showing the No.10. proportions is attached for reference. The port area through the cage is made twice the area of the inlet port from the carburetter, but this is again a feature we shall be in a position to improve if found desirable owing to our wider spacing. LeC.3196 has been arranged with the same timing as normally used on Powerplus blowers in which the amount of compression done in the blower before opening to the induction | ||