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).
Engine improvements for cold weather, focusing on the exhaust heated throttle and a new safety feature.
| Identifier | ExFiles\Box 181\M7\ img045 | |
| Date | 12th December 1924 guessed | |
| (2) are applying to the 40/50, this and many other smaller improve- ments have been introduced. (3) The third point that comes to my mind is that I think we in England and they in America are not doing enough to cater for the poor petrol and cold weather. We want to apply at once the exhaust heated throttle which has been proved out to be the place and the only place where heat is really effective, without disadvantage. This exhaust heated throttle applies therefore more heat in exactly the right spot. In England we do not think the vaporiser scheme is worth the trouble and complication it in- volves, because it is only useful for starting. Naturally the hand controlled louvres with the more reliable thermometer has done much to help, but really this to my mind is all that has been done, together with avoiding certain curious imperfections in the inner surface of the induction pipe. We may add here that we have tried endless modifications to the induction pipes, and the position of the carburetter, but we have found nothing superior to our original standard pipe and position of carburet- ter, provided we maintain the temperature of the water, and get as much heat as we can at the throttle valve. You will remember that in our arrangement we maintain the heat at the throttle by closing a butterfly valve in one of the down exhaust pipes. To avoid any risk of the throttle valve being held open by the sticking of this second valve, we have late- ly arranged for this to be closed by a separate spring on a free lever so that it cannot be the cause of sticking open the main throttle valve. We think this is a patentable feature as it is manifestly valuable for safety. R.{Sir Henry Royce} | ||