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).
Carburetter comparison tests for Eagle engines with different camshafts, pistons and compression ratios.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan156 | |
| Date | 1st August 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -3- Exptl. No. REF: Hs{Lord Ernest Hives - Chair}/TAG/LG26. 8.25. signs of flattening out. The increase at 2300 r.p.m. = 51 B.HP. CURVE III. CARBURETTER COMPARISON. The engine was fitted :- (1) Eagle IX, camshafts (overlap) (2) " Vlll, carburetters and induction system. (3) " IX " " " (4) Standard pistons 5.27 to 1. This shows that when the 4 Eagle Vlll. carburetters and induction pipes are fitted there is an increase of power at lower speeds up to 2165 r.p.m. when the curve flattens and crosses the other. The Eagle IX. carburetters and induction pipes give a good straight line with the power still rising at 2300 r.p.m. A peculiar characteristic is shown, by the dotted line which is common to both curves, but more pronounced with the Eagle Vlll. carburetter. This 'kink' starts at 1900 r.p.m. and comes out at 2200. As the compression ratio is increased and the 'kink' becomes worse and the speed at which it occurs is also changed - see curves 4 and 5. This phenomenon may be due to the increased pressures coupled with the overlap shafts affecting the induction system at these particular speeds. CURVE IV. CARBURETTER COMPARISON - HIGHER COMPRESSION 6.09 to 1. The engine was fitted :- (1) Eagle IX, camshafts (overlap) (2) " Vlll carburetters and pipes. (3) " IX " " (4) Higher compression pistons 6.09 to 1. contd :- | ||