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 from S.U. Carburetter Co. Ltd. addressing float chamber flow, flooding, and fork gear issues for H.4 and H.6 carburetters.
| Identifier | ExFiles\Box 121\3\ scan0059 | |
| Date | 24th July 1939 | |
| TELEPHONE: BIRMINGHAM EAST 1171. TELEGRAMS: FLEXCARBUR, BIRMINGHAM. THE S.U. CARBURETTER CO. LTD. PROPRIETORS:- MORRIS MOTORS LTD. VISCOUNT NUFFIELD CHAIRMAN OLIVER BODEN O.B.E. VICE-CHAIRMAN T. C. SKINNER, M.I.A.E. MANAGING DIRECTOR ADDERLEY PARK, BIRMINGHAM, 8. YOUR REF: Rm.{William Robotham - Chief Engineer}CTS{C. Trot Salt - Carburation}/9/MH.{M. Huckerby} OUR REF: BC/MG. 24th July. 1939. Messrs. Rolls-Royce Ltd., DERBY. Dear Sirs, Experimental Dept. Replying to yours of the 21st regarding the maximum flow through the float chambers fitted to the H.{Arthur M. Hanbury - Head Complaints} 4 and H.{Arthur M. Hanbury - Head Complaints} 6 Carburetters, it is apparent that as you get as much flow through both .100 and .125 seat that the limiting factor evidently is in the pipe work from the pump to the seating. As there is apparently no object in fitting the large seat we will in future fit this with .100 type on both H.{Arthur M. Hanbury - Head Complaints} 4 and H.{Arthur M. Hanbury - Head Complaints} 6 carburetter. Regarding the trouble of flooding with dry float chambers, this we are afraid is unavoidable as until the moving parts are lubricated by the petrol there is a slight lag and this lag is sufficient to give a slight flooding in the float chamber; it should however only be momentary and not at all serious; and as you know in the normal life time of a car in private hands it is very unusual for the float chambers to be quite dry. Regarding your note about occasional jamming of the fork gear, we have not experienced this trouble in any substantial form and if you come across any particular unit giving definite trouble will you kindly forward on to us for our attention and examination. We will send you in the course of a post or so revised specification of the H.{Arthur M. Hanbury - Head Complaints} 4 and H.{Arthur M. Hanbury - Head Complaints} 6 carburetter giving the altered size of neadle seat. Yours faithfully, for THE S. U. CARBURETTER CO. LTD., B. Cooper | ||