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).
Difficulties with carburetter and induction pipe heating and proposing a hybrid solution.
| Identifier | ExFiles\Box 66\2\ scan0119 | |
| Date | 13th November 1925 | |
| COPY OF MEMORANDUM CWB12/LH{Mr Haworth}13.11.25. CJ. c. to BJ. CARBURETTER AND INDUCTION PIPE HEATING. Certain difficulties have appeared in the working of the present system of carburetter or induction pipe heating by exhaust gases, which tend to unreliability, irregularity of working and irritating noise. These are:- (1) Exhaust butterfly sometimes sticks and may not close with the throttle as designed or may not fully open thus tending to baffle the exhaust at higher powers. (2) The heating chamber and surroundings may get too hot on occasions which may lead to heavy petrol consumption. (3) It is very difficult and needs constant, almost daily, care to prevent the exhaust butterfly spindle squeaking on every occasion the throttle is moved. On these and possibly other grounds, a return to the former system of a water heated throttle has been proposed. This system appears to meet all the necessary conditions except one, and to be free from the possibility of trouble from the causes given in the case of exhaust heating. The one condition in which it is much inferior is starting from cold and it would be a seriously retrograde step to change to a system which was inferior to the present, in this respect. A combination of the two systems, however, should produce the ideal: viz. Exhaust heating for starting, and Hot Water heating when properly underway, and it is thought that this can be done without additional complication, on the following lines:- Arrange for the standard heating of carburetter and/or induction pipe to be by means of a hot water jacket, and arrange also a special smaller jacket to be fed from the exhaust, for use when starting and warming up only. The | ||