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 engine performance between 3 and 4 port manifolds with single and double outlets.
| Identifier | ExFiles\Box 86\3\ scan0216 | |
| Date | 13th April 1938 | |
| -2- The loss in power between the 3 and 4 port manifolds is practically negligible, the 4 port being slightly the better of the two. (Curve A and B). Graph A: B.23. O.H.C. VALVE TIMING. I.O. 2° BT.{Capt. J. S. Burt - Engineer} E.O.43° B.B. I.C. 33° PB E.C. 12° PT. LB.8 PLUGS. TAPPETS AT .006" ETHYL FUEL. OPEN EXHAUST. 4 PORT MANIFOLD SINGLE OUTLET. 3 PORT MANIFOLD SINGLE OUTLET. B.H.P. & M.E.P. MEP BHP 3 PORT MANIFOLD 4 PORT MANIFOLD R.P.M. Graph B: B.23. O.H.C. VALVE TIMING. I.O. 2° BT{Capt. J. S. Burt - Engineer} E.O.43° B.B. I.C. 33° PB E.C. 12° PT. LB.8 PLUGS. TAPPETS AT .006" ETHYL FUEL. OPEN EXHAUST. 4 PORT MANIFOLD DOUBLE OUTLET. 3 PORT MANIFOLD DOUBLE OUTLET. B.M.E.P. BHP 3 PORT MANIFOLD 4 PORT MANIFOLD R.P.M. Continued. | ||