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).
Experiments with an auxiliary carburettor versus a heated coil primer, concluding with a recommendation against the primer.
| Identifier | ExFiles\Box 77\1\ scan0089 | |
| Date | 12th January 1921 | |
| R.R. 235A (100 T) (S.H. 159. 11-8-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2800 Contd. -2- Hs{Lord Ernest Hives - Chair}/TMW1/LG12.1.21. provision for this; also it must not be forgotten that the R.R. governed throttle never, under any circumstances, remains closed when the engine stops, nor is it possible, as at pres- ent arranged, to close the throttle by operating control lever, thus necessitating opening bonnet and pushing throttle "closed" if this condition is required. x.4305. We are at present experimenting on some- what similar lines with a small auxiliary carburetter to give excess petrol for starting and warming up conditions, but we have not found any advantage in the electrically heated coil system of the Master Primer, although it certainly warms up the Primer charge; our experience shows that high velocities ( as utilized, for instance, on Pilot Jets) are really better to give a highly volatilized mixture which, combined with rapid exhaust heating, is, we think, the better scheme. The coil is only capable of warming up the charge lying in the chamber and not of any spirit passing through. We, therefore, for reasons set out above, cannot recommend to Mr. Royce the adopt- tion of this Primer in its present form; at the same time, however, the scheme has been well worth investigation and of considerable assistance to us in our experiments on this subject. Hs{Lord Ernest Hives - Chair}/TMW. | ||