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).
Blower efficiency and a summary of a supercharged car, with comparisons to Graham Paige and Duesenberg models.
| Identifier | ExFiles\Box 178\2\ img151 | |
| Date | 4th April 1934 | |
| -4- BLOWER EFFICIENCY. Graham Paige have designed and built this blower themselves with a little assistance from one of Duesenburgs men. They know as an approximate figure that the blower efficiency is less than 50%, but they do not know how to do any better to get the blower silent and also effective over a considerable speed range. SUMMARY. This is the first supercharged car I have ever tried, which can be said to have lost nothing in silence or smoothness by the application of the device. It has been developed in a very simple and economical form. It would enable us to use a Rolls-Royce camshaft on the Bentley with consequent increase in silence and reduction in timing gear noise, and at the same time improve the performance over the whole speed range and the top power output by at least 25 to 30%. The valve gear will have a much easier time, and recent piston and bearing developments should enable us to utilise the power without mechanical failure. We have been using this type of blower for a number of years on aircraft engines and therefore we are familiar with its design. The Graham engineers impress one as being practical individuals who have not rushed light-heartedly into production, but are convinced that the application stands a reasonable chance of success. They also intend to maintain a high standard of silence on the units. The two cars I tried were almost equally silent. Unfortunately, apart from the engine unit, the Graham is not in step with the best contemporary American practice, in particular its directional stability is inadequate for its top road speed. The complete 8-cyl. supercharged car with a 4-door sedan body sells in the States for just over 1500# HS{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||