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).
Test report on S.U. carburettors for a 19-G-IV chassis, including modifications to an induction pipe balance piece.
| Identifier | ExFiles\Box 31\5\ Scan029 | |
| Date | 16th March 1933 | |
| Hs.{Lord Ernest Hives - Chair} from Hs{Lord Ernest Hives - Chair}/G.H. Whyman. X1487 S.U. CARBURETTERS ON 19-G-IV. (BENSPORT UNIT). We have now completed a series of tests with the above carburettors (1 1/8" Inlet port) on a Bensport Unit fitted in 19-G-IV. chassis. Our first tests were carried out with the two carbs. fitted to Lec.3277, E.59292/3, Ex.10401 Mod. cast aluminium induction pipe, which had a plain .500" hole balance piece fitted in the centre of the pipe. In this condition we obtained fairly good results, the slow running being quite good, i.e. 7 m.p.h. on top gear, ignition fully advanced, pick up from all speeds very good except for a slightly weak spot from 28 m.p.h. to 34 m.p.h. when the engine was warming up (once the engine gets really hot this weak spot fades out), and high speed running very good. The induction roar, however, was terrific and from 35 - 55 m.p.h. and 65 m.p.h. upwards it completely "drowned" every other noise on the car. We next removed the .500" hole balance piece and fitted another one with a 1.00" hole in the centre and the body extending for 1.00" in each half of the induction pipe as per sketch. [Drawing Text] 2.00" 1.500" DIA 1.00" DIA SWEAT FLANGE TO SUIT FLANGES FITTED TO INDUCTION PIPE | ||