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).
Tests on different sized S.U. carburettors on a J.1 engine.
| Identifier | ExFiles\Box 31\4\ Scan238 | |
| Date | 9th November 1932 | |
| r1487 E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to Hy.{Tom Haldenby - Plant Engineer} c. to Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}4/MA.9.11.32. S.U. CARBURETTERS. ----------------- We have now carried out some tests on the S.U. carburettors on J.1 engine, the attached curve shows the results. In order to get reasonable slow running and stability at slow speeds when we use the two 1.625" S.U. carburetter we have to have a balance piece in the induction pipe. With the two 1.375" S.U. carburettors, we do not have to have the balance in the induction pipe. Therefore comparing curves 1 & 3 you will observe there is not more than 2% difference in power at the higher speeds in favour of the larger carburetter, and 2% in favour of the small carburetter at the low speeds. Additionally we consider that the smaller carburettors with no balance piece in the induction pipe ought to give us crisper acceleration and better slow running. We are carrying out road tests to prove this. The smaller carburettors help us to get our air silencers under the Bensport bonnet. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||