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 showing the results of 20/25 HP exhaust tests for a resonance silencer.
| Identifier | ExFiles\Box 104\2\ scan0042 | |
| Date | 14th June 1932 | |
| UNIT C.S. (CHINA) RESONANCE SILENCER 20/25 H.P. EXHAUST TESTS. COMP RATIO 5.7:1 CAMSHAFT E57177. (CAM FORM E57175) STANDARD INDN SYSTEM EXH. 2" MANIFOLD & AIR BOX (R.B 6.13) WITH ① COMPLETE SILENCER (P.I. SWAN-NECK) ② DITTO BUT WITH 20 H.P. SWAN-NECK ③ DITTO SWAN-NECK REMOVED ④ AS ① WITH BAFFLES Ⓐ & Ⓑ REMOVED EXHST. BACK PRESS. "Hg B.H.P. RPM P.I. (SHORT TYPE) SILENCER WITH STANDARD SWAN-NECK (20/25) Diagram Text: EX IN BDC 106° 67° 45 R° | ||