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).
Deficiencies in carburettors and starting devices and proposing a new design.
| Identifier | WestWitteringFiles\G\October1921\ Scan52 | |
| Date | 10th October 1921 | |
| To HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} Copy to CE. [strikethrough] [Handwritten]: X2768 X4387 [STAMP: ORIGINAL] [STAMP: RECEIVED with clock face] RE CARBURETTORS AND STARTING DEVICES. [Handwritten]: X4390 X1449 We conclude from your memos that all starting devices are very defective. We have endeavoured to improve on such as the Zenith, which may be considered a standard one, and also to improve on the system of a simple choking device, such as is used by the Americans and by Claudel-Hobson. Now it seems quite evident that we require a starting device which will continue to run the engine both cold and hot with the necessary mixture, both in strength and quantity, for the very wide conditions that one meets with. This apparatus now appears to be equally exacting to the main carburettor, inasmuch as it should give an increasing strength the lower the suction, rather than the reverse, which is natural to simple carburettors. This cannot be accomplished without a device which has a mechanical movement, which is confirmed by the experience with the main carburettors. We are therefore sending within the next day or two, a modification to the small jet at the side of the floatfeed chamber, having the features similar to that sent by you of a moving throat, but we are endeavouring to avoid the use of the spring, and also arranging the apparatus so that it automatically reduced itself to almost a choked carburettor. We are not sure whether it will be found necessary to let this apparatus be always connected so as to give extra good slow running, but for the sake of simplicity and urgency, it may be considered that the two-jet carburettor of our standard type will do all the range we need, and that the small jet need only be brought in action during (Contd.) | ||