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).
Performance graph of BHP and BMEP vs RPM for a Unit C.9 engine with varying intake manifold restrictions.
| Identifier | ExFiles\Box 85\4\ scan0014 | |
| Date | 6th February 1933 | |
| BENSPORT J.1 FEB 6 1933 UNIT C.9 COMP RATIO 6.3:1 (STANDARD E.S6604) CAMSHAFT E.S9139 (113 1/2°) 2 S.U. 1.375 CARBS ON CAST ALUM. PIPE WITH VARYING SIZE RESTRICTION HOLE ① 1.5 DIA. BALANCED PIPE ② 1.000" RESTRICTION ③ .750 ④ .500 ⑤ BLANK (UNBALANCED) B.H.P. R.P.M. B.M.E.P. C.H. T.D.C 6.5° 3.5° 50° 54.5° B.D.C (TAPPETS AT .020) CARBS BETWEEN 2x3 & 4x5 1 2 3 m 4 5 6 CENTRE RESTRICTION OVERHANG OF BUFFER ENDS PAST OUTSIDE PORTS REDUCED 50% | ||