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).
Comparison of power output between a Claudel carburetor and a single jet expanding S.U. carburetor.
| Identifier | ExFiles\Box 182\M19\ img267 | |
| Date | 28th October 1931 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Ra. c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to Mr. E.{Mr Elliott - Chief Engineer} c. to Ry. Hs{Lord Ernest Hives - Chair}/Ra.3/KT.28.10.31. X1487 X1452 POWER OUTPUT. SINGLE JET EXPANDING CARB. COMPARED WITH CLOSED CHOKE DIFFUSER TYPE. We obtained a power of 94 B.H.P. with a Claudel carb., free area past choke 1.46 sq.in., on a Japan unit with a 112° shaft, high lift valves and a c/r of 5.13 When we tried to reproduce this with an S.U. we were 10 HP. down, as shewn on Curve (1). The distribution with the S.U. appeared to be quite good at the top speeds with pipe 'B', but in view of the large discrepancy in power output between the two carbus. we decided to try another pipe on the S.U. 'A'. This pipe gave an increase of 8 B.H.P. and almost equalled the Claudel though it was poor for distribution at low speeds. The inference we draw from these results is that we can get as good power from a single jet as a diffuser, though the former is more susceptible to distribution troubles. Incidentally we took the induction pipe depn. opposite No.4 & No.6 cyls. in these tests and you will note that the results shew quite a wide variation in depression between the two points. Hs{Lord Ernest Hives - Chair}/Ra. 2 photographs also att: to R & E's copy. | ||