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).
Notes on the relative merits and fuel consumption of fixed choke and expanding carburettors.
| Identifier | ExFiles\Box 147\5\ scan0190 | |
| Date | 4th September 1941 | |
| Rtn from Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} FILE IN 1249 1. NOTES ON THE RELATIVE MERITS OF FIXED CHOKE AND EXPANDING CARBURETTORS. We have this evening completed a petrol consumption test on 1 RT 1 fitted with a 1 1/4" S.U. carburettor and a No. 2 needle. The consumption is 23 MPG at an average speed of 38 MPH. for 66 miles. 23 M.P.G. was found to be the very best possible consumption with a fixed choke Stromberg carburettor (see Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden}10/SW.4.9.41). It therefore follows that if separate tests are accepted as conclusive - and since we have only one B40 unit no other method is possible - these tests provide a direct basis of comparison for the two types of carburettor. Arguments for the two types may roughly be lined up as follows - | ||