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).
Development and compromises of thermostatically controlled shutter and induction systems.
| Identifier | ExFiles\Box 39\4\ Scan203 | |
| Date | 25th November 1930 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to BY.{R.W. Bailey - Chief Engineer} EP.{G. Eric Platford - Chief Quality Engineer} X3499 RL/M25.11.30. CAR WORK - THERMOSTATICALLY CONTROLLED SHUTTERS. X.7250. X.3499. It is somewhat difficult to exactly understand all the moves and compromises that we have to make to get the best out of so complicated an apparatus as a car, for its various conditions of climate, fuel, and even altitude on mountain passes, ( in Switzerland, etc.) In the Silver Ghost we had a rather difficult induction system, which, to meet the lower grade petrol after the war we had to adopt ample exhaust heat to the throttle, because the water temperature was at its highest too low for poor petrol in cold weather. After this the water and bonnet temperature had very little to do with the distribution which is the feature that often asks for more heat. In P. 1. we placed the carburetter close to the exhaust and altogether got more heat than I liked - i.e. risk of boiling petrol, etc. In P. 2. we very much improved the distribution which is now fairly good even cold, so far from a distribution point of view we did not need anything like so much heat, and because the exhaust heating valve had given much trouble we returned to water heating of the throttle. This was afterwards thought to be insufficient on special occasions of low temperature, cold weather, and bonnet. We then returned to exhaust heat and but for the heated air under the bonnet the water temperature has no effect on the carburation system until the fuel gets into the cylinders. We had relied upon Derby acting upon our suggestion of increasing the exhaust heating. But it may be also advisable to allow of a higher temperature before the thermostat opens the shutters, and rely upon any boiling difficulties being met by detaching the shutters from the control and letting them be permanently open when the conditions suggest it. We have allowed for this in our design - i.e. the work of one minute. R.{Sir Henry Royce} | ||