The efficiency and coupling of a Roots type blower compared to a Powerplus system.
| Identifier | ExFiles\Box 3\4\ 04-page032 | |
| Date | 11th May 1932 | |
| - 3 - E.1/HW.11.5.32. ---------- (3) Higher overall efficiency. (4) Begins to operate at a lower speed than the Roots due to smaller leakage factor. (5) It is not necessary to have a by-pass passage shunting the blower for slow running. In coupling up the Roots type blower on the Bensport(Codename for 3 1/2-litre Bentley) to the front end of the crankshaft we have shown the blower shaft hollow with a flexible driving shaft passing through it. This scheme is not possible on the Powerplus due to the vanes intersecting the shaft, and we shall have to use a spring coupling for this purpose. With regard to the starting handle it was said that the blower shaft would be sufficiently stiff for the purpose of turning the engine. K. {Mr Kilner} | ||
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).