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).
Butterfly valve noise and recommendations regarding the exhaust-heated throttle.
| Identifier | ExFiles\Box 74\2\ scan0068 | |
| Date | 4th July 1922 guessed | |
| contd:- -2- take it the other way, down and through between the cylinders. There is another point in connection with the butterfly valve in the exhaust pipe, owing to the pulsations of the exhaust pressure in the pipe the valve is liable to make a noise if there is any slack at all in the bearing. To overcome this we fit a spring which keeps the valve pulled over in one direction. We also want to impress upon you that according to how the valve is adjusted, one can get practically any temperature on to the throttle, and you will be surprised to find what a small percentage drop in power there will be even with the valve considerably shut off. We are also thinking of recommending that with the exhaust heated throttle, the brass spinning which is soldered into the throttle piston, should be left out. We do not believe this spinning has any affect at all, but we have had a case where we have run the car continuously on the hand control throttle so that the butterfly in the exhaust pipe was closed the whole time, and when the engine has been stopped down, the throttle has been so hot that it has melted the solder. It is alright whilst the engine is running because the liquid petrol spraying on to this part, keeps it reasonably cool. HS.{Lord Ernest Hives - Chair} | ||