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).
Letter to the Managing Director discussing the design of heated induction pipes in American engines.
| Identifier | ExFiles\Box 50\3\ Scan034 | |
| Date | 25th March 1921 | |
| Oy4 - G 25321 March 25, 1921 Mr. Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Attention: Mr. Royce & Mr. Hives. Dear Sir;- Re: Heated Induction Pipes (1) General Design of American Induction Pipes. We wish to bring to Mr. Royce's notice the fact that practically all new American designs have incorporated an exhaust heated induction pipe. Also, the inlet pipe has been as short as possible, and as small as it can be made without cutting down the power seriously at high speed. In all except Vee engines the pipe from throttle to manifold is generally vertical, and the manifold is generally designed so that all liquid petrol will drain back to the carburetter. I think we used to have the impression in England that American induction pipes were made small to limit the power of the engines, and by increasing the vacuum to improve the working of carburetters which were defective in design. The power curves of American cars, however, go to prove that the power is generally maintained well at high speeds. The effect of a high vacuum on getting more constant carburation at various speeds may be important with some of the cruder American carburetter designs. The chief reason for the small and short pipe, however, is certainly to keep up a high gas velocity so that it is possible to obtain good distribution with the very inferior gasoline. | ||