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).
List of modifications and considerations for carburettor components.
| Identifier | ExFiles\Box 31\5\ Scan273 | |
| Date | 11th December 1934 guessed | |
| - 2 - will be made in magnesium, treated with Chromate and S.U. are confident that there will be no deterioration due to the use of leaded fuels. To avoid having a loose flange on the pattern of the floatchamber, as far as possible, S.U. will consider enveloping the upper facing with the shape of the casting below, so that the flanges can all be turned inward and the stud centres moved in to tap out on the inside instead of on the outside, as now. (4) Slow running adjustment screw. The S.U. propose setting this at an angle of about 45°, which enables the head of the screw and the locking nut to be brought right clear and entirely accessible. It also leaves room for the dust cover for the operating mechanism, which need no longer be gapped on the inside wall. With this modification the covers should be reasonably air-tight, for the purpose of excluding grit, and it may even assist in testing for altitude. (5) Richening Aneroid. S.U. have a stop to avoid excessive movement, but this has apparently been left off, and they will supply further particulars. (5) Altitude Aneroid. The chamber for this should be communicated to the air inlet by a drilled hole low down, which, in addition to equalising would also act as a drain. (6) Enrichment Control. It was agreed that S.U. should cancel the enrichment on the full throttle end of the enrichment cam, and replace it with a trigger mechanism on the altitude jet also coupled to the throttle. The lever required on the throttle spindle for connection to the enrichment cam is so short at present as to render it difficult to provide the necessary mechanism. More movement should be, therefore, allowed for on the cam | ||