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).
Analysis of the limitations of the exhaust heated throttle and a comparison with a vapouriser scheme.
| Identifier | Morton\M22\ img160 | |
| Date | 10th October 1922 | |
| Hs{Lord Ernest Hives - Chair}6/T5.10.22. -2- Contd. (3) It increases the complicated appearance of the engine. It should be realised that the exhaust heated throttle has limitations. Under any normal conditions met on the road we think it will do all that is required, but it is possible if the engine is run full throttle at 400 or 500 revs. for half a-mile or so, that there will be an occasional miss-fire when it accelerates. We know at very low speeds full throttle, the exhaust heated throttle is no hotter than the present standerd water heated throttle. If, however, there is ever any condition which demands that the engine shall run full throttle at 400 or 500 revs. continuously, if the hand throttle is used instead of the foot accelerator, there will be no trouble whatever. Some time ago we considered recommending the vapouriser scheme without the exhaust heated throttle as a first move. The vapouriser scheme when fitted to a car without exhaust heated throttle does give a distinct improvement. Our tests show, however, that there are a number of points to be considered to get the best from the vapouriser. If we take an engine which suffers from bad distribution and on which the power at low speeds cannot be maintained, and we fix on to the inlet branch for each cylinder a drain pipe, and drain those pipes into a vessel, that engine will run perfectly until the vessel gets full up with petrol. What happens is that the excess petrol which must be supplied to | ||