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).
Graph of performance data from resonance silencer exhaust tests on a Phantom II unit.
| Identifier | ExFiles\Box 104\2\ scan0057 | |
| Date | 2nd August 1932 guessed | |
| PI 25 UNIT PHANTOM II RESONANCE SILENCER EXHAUST TESTS RM{William Robotham - Chief Engineer} P 59 P.E. COMP RATIO 5.25:1 W.R.R. (149) CAMSHAFT SEMI-EXPANDING CARBS EXH. BACK PRESS "Hg B.H.P. B.M.E.P. R.P.M. KEY: ① OPEN EXHAUST ② SILENCER H.S. 647 ③ AS ② SWAN NECK & FISH TAIL REMOVED ④ P.II (LONG TYPE) SILENCER ⑤ P.II (SHORT TYPE) SILENCER ⑥ C.O. OPEN AS ⑤ ⑦ AS ③ TWO FRONT BAFFLES REMOVED TIMING HS{Lord Ernest Hives - Chair} 29-B-82 | ||