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 comparing a full exhaust system against a manifold-only system with the cut-out open.
| Identifier | ExFiles\Box 14\6\ Scan234 | |
| Date | 30th November 1931 | |
| COMPARISON OF MANIFOLD ONLY C.O OPEN & FULL EXHAUST SYSTEM P.II COMPLETE SHORT TYPE EXHAUST SYSTEM 114° CAMSHAFT TO EB24448 4.65 C/R STD. CYL HEAD 1.9" VALVE THROAT MANIFOLD ONLY R.R TWIN CARBS 1.4 DIA. CHOKES. C.O OPEN COMPLETE P.II SHORT EXHAUST SYSTEM Valve Timing Diagram: Ex 60, IN 15, 55, .013 CLCE Y-Axis Left: B.H.P. Y-Axis Right: B.M.E.P. LBS/SQ X-Axis: R.P.M Graph Labels: FULL EXHAUST SYSTEM EXHAUST BACK PR B.H.P C.O Closed C.O. OPEN EXHAUST BACK PRESS | ||