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).
Car performance test results comparing a semi-expanding carburetter against standard and S.U. models at Brooklands.
| Identifier | ExFiles\Box 13\4\ 04-page010 | |
| Date | 23th July 1932 | |
| 87080. To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c.c. to Sg.{Arthur F. Sidgreaves - MD} For. c.c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c.c. to By.{R.W. Bailey - Chief Engineer} Ref: Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/WJ.23.7.32. x788 CAR PERFORMANCE. SEMI EXPANDING CARBURETTER. BROOKLANDS TESTS. We have now completed a series of tests on acceleration and on Brooklands track, comparing the R.R. semi-expanding carburetter, the two S.U. carburetters, and the standard carburetter. The hill climbing results were as follows :- Condition. Stanton Hill 20 MPH. Climb. Ticknall Hill 50 MPH. Climb. Pilstern Hill 30 M.P.H. Climb. Standard Carb. 22.4 58.8 60.8 S.U.Carb. 22.4 55.8 56 R.R. Semi-Exp. Carb. 21.2 56.5 55.8 All Tests C.O. Closed. Time. Secs. The results shew that the R.R. Semi-expanding carburetter is particularly good at low speed full torque pulling and beats the two S.U.'s under these conditions. The two S.U.'s gain on the faster speed climb but are only slightly better. All these tests were taken C.O. closed which, as we subsequently shew, largely nullifies the gain due to the better breathing of the engine. The R.R. semi-expanding has been greatly improved in snap acceleration from its original condition and now gives a lively feel to the car, a great deal more so than the standard instrument. Fig.2 shews the gain in acceleration over the standard car with the R.R. semi expander, long duration camshaft etc.. | ||