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).
Power and B.M.E.P. curve graph for a Wraith III engine, comparing various valve configurations.
| Identifier | ExFiles\Box 10\3\ 03-page149 | |
| Date | 1st June 1935 | |
| WRAITH III POWER VALVES R.P.M. B.M.E.P. H.P. ① 5.85:1 COMP. RATIO CYL HEAD EX. 29686 (CAP 134.5 C.Cs.) INLET VALVE 1.50" EX 29686 EXH. VALVE 1.30" EX 29687 ② * 6.0:1 COMP. RATIO AS 1 BUT WITH INLET VALVE 1.60" EW 1429 EXH. VALVE 1.30" EX 29687 } OPEN EXHAUST ③ * (A5) 6.0:1 COMP. RATIO AS 1 BUT WITH INLET VALVE 1.60" EW 1429 EXH. VALVE 1.40" E 61289 (MOD EX 31328)(CAP. 130 C.C's) ④ * (A5) 6.0:1 COMP. RATIO AS 1 BUT WITH INLET VALVE 1.60 EW 1429 EXH. VALVE 1.40 E 61299 (STD. THROATS) CAP. * TAPER THROATS NOTE THE SAME CYL. HEAD IS USED THROUGHOUT BEING MODIFIED IN STAGES FROM SMALL VALVE TO STD VALVE HEAD | ||