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The results of tests with a low lift camshaft on an EAC engine.


Identifier  ExFiles\Box 72\1\  scan0227
Date  17th September 1924
  
R.R. 403A (40 H) (SL 42 12-7-23). J.H., D. {John DeLooze - Company Secretary}
EXPERIMENTAL REPORT.
Expl. No.
REF HS {Lord Ernest Hives - Chair} /GHP/LG17.9.24.

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 | xxx | xxx | 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% |
  
  
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).


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