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).
Pros and cons of a vapouriser scheme for the 40/50 chassis.
| Identifier | ExFiles\Box 183\M22\ img159 | |
| Date | 1st October 1922 | |
| FUEL DISTRIBUTION, 40/50 & 'CASWELL'S BOILER' Hs{Lord Ernest Hives - Chair}6/T5.10.22. H.S PUTS THE PROS & CONS OF THE BOILER & EXH. HEATED THROTTLE & COMES DOWN ON THE SIDE OF THE LATTER (TO SCOTCH STANDARDISATION OF THE FORMER)- VAPORISER SCHEME FOR 40/50 CHASSIS. We have lately issued a standardisation sheet for the vapouriser for the 40/50, but we doubt whether when this scheme is used in conjunction with the exhaust heated throttle it is worth the extra complications which it entails. The vapouriser scheme when used in conjunction with the exhaust heated throttle practically only functions when the engine is started up from cold and the pilot jet is in operation. Even under that condition it should have very little to do because the exhaust heated throttle enables the engine to run on the main carburetter practically immediately and after a very short run the mixture can be put in the normal position. The disadvantages in the vapouriser scheme are :- (1) Increased risk of leaky induction system and very great difficulty in locating these leaks when they occur. A slight leak in the vapouriser boiler, or pipes not only affects the slow running of the engine, but also prevents the vapouriser scheme from functioning. We have been running vapourisers for over 12 months and on two occasions have had trouble with the welded seams in the boilers cracking. The exhaust down pipes on the 40/50 engine are generally difficult to connect up and frequently have to be pulled about, with the boilers fitted on to these, they will have to be handled very carefully. (2) The pipes interfere with accessibility of removing the valves and to a lesser degree adjusting the tappets. Contd. | ||