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).
The results of tests with a low lift camshaft on an EAC engine.
| Identifier | ExFiles\Box 72\1\ scan0188 | |
| Date | 17th September 1924 | |
| R.E. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} EXPERIMENTAL REPORT. Expl. No. REF:- GHF/LG/17.9.24. RESULTS OF TESTS WITH 118° LOW LIFT CAMSHAFT ON EAC. ENGINE. NO.1-EAC-11. Conditions :- 1.500" longer rods. Camshaft E.71994 118°. Pistons E.72195 R = 4.8/1. EAC. carburetter with alum: air valve. Scintilla Magneto with automatic advance. 1.000" packing under cyl. block. Twin exhaust system. Alum: Induction Pipe. Power curve. .010" tappet clearance. Valve timing used I.O. 12.6° P.T.C. E.O. 59.7° B.B.C. I.C. 41.2° P.B.C. E.C. 3.6° P.T.C. Tappet clearance for tests .004". | | C.O. closed | | | C.O. open | | High lift Cam. | | | |---|---|---|---|---|---|---|---|---| | R.P.M. | Lbs. | B.HP. | Pts.hr. | Lbs. | B.HP. | Lbs. | B.HP. | % Difference. | | 2750 | [113] | [117.7] | [xxX] | [xx] | 118 | | 104.5 | | | 2500 | 113 | 117.7 | 73.7 | 119.5 | 124.5 | 121 | 126 | 1.2% | | 2250 | 123 | 115.2 | 72.5 | 131.5 | 123.5 | 133 | 124.8 | 1.0% | | 2000 | 133.5 | 110.7 | 68.4 | 139.5 | 116.2 | 141 | 117.5 | 1.1% | | 1750 | 139 | 101.3 | 62 | 142.5 | 103.5 | 146.5 | 106.9 | 2.2% | | 1500 | 142 | 88.7 | 59 | 144.5 | 90.3 | 148 | 92.5 | 2.3% | | 1250 | 144 | 75 | 46.8 | 145.0 | 75.5 | 148 | 77.3 | 2.3% | | 1000 | 140 | 58.3 | 40 | 143 | 59.5 | 146 | 60.8 | 2.1% | | 750 | 142 | 44.3 | 31.9 | 143 | 44.7 | 146 | 45.6 | 2.0% | | 650 | 144 | 39 | 27 | 146 | 39.5 | 148 | 40.7 | 2.6% | | ||