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).
Letter discussing experiments with the Goshawk starter carburetter for improved slow running on the EAC.2 chassis.
| Identifier | ExFiles\Box 5\4\ 04-page143 | |
| Date | 16th October 1924 | |
| To BY.{R.W. Bailey - Chief Engineer} } FROM R.{Sir Henry Royce} To HB.{C. E. Harcombe} } S E C R E T. X4228 R2/M16.10.24. EAC.2. CHASSIS. X.8770 X.4219 X.4228. You do not say the date on which we are to expect you with the EAC.2. We have been making some experiments with the Goshawk and find that we can get more consistent slow running by using the starter carburetter as part of the running equipment, as we suggested in the original Goshawk scheme which was afterwards abandoned for simplicity. We find however on 4-G-11 that the carburetter as we are fitting it is quite satisfactory down to 4-m.p.h. even though this car has been out for hire for some months and has not been overhauled. (We found however, that the carburetter as delivered to us was wrongly adjusted, and the sparking plugs were dirty and uneven in their adjustment. The engine however ran perfectly after these simple corrections.) We are pleased to hear that you have the same opinion as regards the EAC.2. engine, that is, it is quite satisfactory and equal to the 40/50 and 20 HP. Last week we spent considerable time endeavouring to make the starting carburetter suitable for ordinary slow speed running, and perhaps by further additional work we shall be able to do so if it is found necessary. At the same time if it is unnecessary, we consider it is somewhat undesirable, as it is another item requiring careful adjustment so as to prevent it doing more harm than good. We have therefore decided to leave this attempt until after we have seen how the EAC.2. behaves with the latest modifications to the main carburetter. It will be remembered that the fault we pointed out was that after a spurt of speed the carburation was poor for a time and then recovered. We could detect the same fault on the Goshawk, that is, after racing the engine and dropping back to a nearly closed throttle position, the engine would misfire, whereas after racing the engine and dropping back to a carefully adjusted starter carburetter, the engine continued to fire evenly. This however may be a hypercritical condition which does not worry us in practice. R.{Sir Henry Royce} | ||