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 Bendix-Perrot Brakes Ltd. discussing comparative carburetor performance and enclosing mixture ratio curves.
| Identifier | ExFiles\Box 122\1\ scan0138 | |
| Date | 13th September 1932 | |
| YH660 BENDIX-PERROT BRAKES LTD. MECHANICAL BRAKES for AUTOMOTIVE VEHICLES CABLES & TELEGRAMS: "BENDIXCORP-BIRMINGHAM" TELEPHONES: ACOCKS GREEN, 1601-2-3. Kings Road TYSELEY BIRMINGHAM DIRECTORS: VINCENT BENDIX, U.S.A. HENRI PERROT, French. HERBERT CLARK, English MANAGING DIRECTOR. September 13th, 1932 Messrs.Rolls-Royce, Ltd., Derby. Attention Mr.W.A.Robotham. Dear Mr. Robotham, At Mr.Clark's request, I am sending you one or two curves which show the comparative horsepower and consumption readings obtained on several makes of engine with the Stromberg Carburetor, running under exactly the same conditions as those of other makes. The curves are quite typical of the results which we usually obtain, and in all cases were run as nearly as possible under exactly the same conditions with, in either case, the best setting which could be obtained from the particular carburetor used. I am also enclosing three mixture ratio curves taken off the Air Box; one of these being of an S.U. carburetor, and this is merely being sent to you as a comparison of principle. This particular carburetor was, of course, a stock article, taken off a car, and may possibly have been out of adjustment, but the form of the curve is very typical of all mixture ratio curves I have seen made from carburetors of the constant vacuum type. The other two curves show mixture ratios obtained with the Stromberg UXT.3. carburetor, which is the 1½" vertical type, and the particular carburetor concerned is now in use on a double-decker bus in Leeds, and has given as much as 12 m.p.g. consumption, or well over 90 ton miles. The other curve shows a standard DX.3. Special Down-Draft carburetor, as fitted to the Humber "Snipe", and is actually the curve of a carburetor which was found to be slightly defective, due to a very slight leak from the accelerating pump, which accounts for the bad shape of the closed throttle curve from 6 lbs onwards, but it also shows Bendix-Perrot Brakes Ltd., take every precaution against fire, but do not accept liability for any injury which may be caused by fire to any Motor Vehicle or part thereof entrusted to them for any purpose whatsoever. Customers' Cars are driven by our Staff at Customers' own Risk and Responsibility. | ||