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).
The advantages and disadvantages of water-heated versus exhaust-heated carburetter systems.
| Identifier | WestWitteringFiles\L\2April1924-June1924\ Scan56 | |
| Date | 1st May 1925 | |
| R.R. 493a (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. Expl. No. REF: Hs{Lord Ernest Hives - Chair}2/LG1.5.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. BJ. c. to E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} c. to DA.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} RE: CARBURRETTER HEATING. X766 X.8030 X.2708 The advantages we can see from reverting to the water heated throttle is that we get rid of the choke valve in the exhaust pipe which is liable to stick open and so allows very little heat to the carburetter, and it is liable to either squeak and rattle. We cannot say that it is going to make any difference to the over-heating problem. We shall lose also the advantages of exhaust heating. (1) Starting up from cold. Unfortunately quite a lot of people never experience starting up a car from dead-cold and take it on the road - they receive it in a warmed-up condition. With the water-heated throttle it is impossible to get the car under way for a period of time. If it is attempted the engine will pop, splutter and stop. To avoid this the usual practice is to leave the starter carburetter working. *This is the worst possible thing to happen because raw petrol is poured into the cylinders.* We agree that we would like the minimum amount of heat to the carburetter but as we shall not overcome the over-heating troubles by this move, we strongly recommend caution before we change cars wholesale. The distribution on the 40/50 car until the carburetter is warm, is poor. contd :- | ||