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).
The performance and characteristics of a Graham Paige centrifugal blower supercharger.
| Identifier | ExFiles\Box 178\2\ img148 | |
| Date | 4th April 1934 | |
| To: [Illegible] [Illegible] [Illegible] [Illegible] c. to E.V. [STAMP: RECEIVED APR 8 1934] SUPERCHARGING BY CENTRIFUGAL BLOWER. GRAHAM PAIGE. Contrary to expectations, this method of car supercharging appears to be practical and efficient. The Blower is perfectly silent judged from the driving seat of a saloon car; by lifting the bonnet and revving the engine up light it can be heard but even under these conditions is no more noisy than the fan. The improved performance is noticeable from 35 M.P.H. upwards. At 45 M.P.H. the increased acceleration is marked. That the blower actually does improve the engine efficiency at these speeds is proved by the curve of induction pipe depression with and without supercharge. Engine R.P.M. 1000 1500 2000 3000 4000 Induction Depn. } Naturally } -.2 -.6 -1.00 -2.00 -3.00 Aspirated } Induction Press. } Supercharged. } +.2 +.6 +1.6 +3.70 +6.00 Induction pipe pressures given in ins. Hg. Owing to the fact that the boost pressure obtained is only light up to 2000 R.P.M. it has not been found necessary to change the engine compression ratio which remains at 6.72-1. The power of the engine, which is side valve 265 cu.ins. displacement, has been raised from 92 H.P. at 3300 R.P.M. to 132 HP. at 4000 R.P.M. | ||