Carburetter modifications, airflow, and induction pipe depression tests.
| Identifier | ExFiles\Box 13\4\ 04-page135 | |
| Date | 20th March 1933 | |
| -2- We do not see any reason why the air valve and throttle body should not be more centrally situated in the passage from the air valve to the choke. At present the air valve port appears to be in a position where the flow is restricted by the casting. V.1529 shows the layout of the carburetter body which we conclude from our tests would give the lowest depression in conjunction with good distribution. The modifications previously described would necessitate re-metering of the carburetter, but in any case it is essential to incorporate the modification of the higher feed level from the diffuser to the slow running unit to avoid 'luffing up' trouble, described in our previous reports on expanding carburetters. Other tests include cutting out the roof of the passage between the air valve and the throttle body indicated by (A) in (V.1530), in order to increase the passage area. This gave no reduction in induction pipe depression but produced erratic distribution. Complete removal of the air valve reduced the depression to 1.8 Ins.Hg. which, with the larger throttle body appears the lowest figure we can obtain, for even with a slot cut in the body, indicated by (C) (V.1530), there is no further reduction in depression. One interesting test was that after removing the air valve a blank plate was fitted in its place and resulted in an induction pipe depression of 2.2 Ins.Hg. Upon replacing the air valve the depression lowered to 2.00 Ins.Hg. Hs {Lord Ernest Hives - Chair} /L.H.Swindall. | ||
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).