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Vibration data for a single-cylinder L.C. sleeve valve 4.2' engine under various conditions.


Identifier  ExFiles\Box 134\1\  scan0106
Date  13th October 1938 guessed
  
SINGLE CYLINDER L.C. SLEEVE VALVE ENGINE 4.2" ENGINE. VARIATION OF VIBRATION WITH DIFFERENT ENGINE CONDITIONS.

| | R.P.M. | B.M.E.P. (lbs/sq.inch) | Plug | | Centre of head. | | Head Flange. | | Crankcase. | |
|---|---|---|---|---|---|---|---|---|---|---|
| | | | Range. | Freq. x R.P.M. | Range. | Freq. x R.P.M. | Range. | Freq. x R.P.M. | Range. | Freq. x R.P.M. |
| POWER CURVE | 3000 | 207 | .020" | | .021" | | .010" | 1/2 | .003" | 1/2 |
| RUN AT 16" | 3200 | 204 | .022" | | .024" | | .012" | 1/2 | .005" | 1/2 & 1 |
| BOOST. | 3400 | 207 | .023" | 1/2 | .025" | 1/2 | .014" | 1/2 | .005" | 1/2 & 1 |
| | 3600 | 207 | .024" | | .027" | | .014" | 1/2 | .005" | 1/2 & 1 |
| | 3800 | 208 | .026" | | .028" | | .015" | 1/2 | .006" | 1/2 & 1 |
| | 4000 | 210 | .036" | | .039" | | .015" | 1/2 | .006" | 1/2 & 1 |
| | 4200 | 202.8 | .043" | | .045" | | .015" | 1/2 | .007" | 1/2 & 1 |
| | 4400 | 198.5 | .040" | | .042" | | .016" | 1/2 & 1 | .007" | 1/2 & 1 |

| | IGNITION. (°advance) | B.M.E.P. | Plug | Insert. | Centre of head. | Head Flange. | Crankcase. |
|---|---|---|---|---|---|---|---|
| IGNITION | 25 | 142 | .013" | | .014" | | .005" | | .003" | 1 |
| ADVANCE RUN | 26 1/2 | 145.5 | .014" | | .015" | | .008" | | .003" | 1 |
| | 30 | 150 | .028" | 1/2 | .027" | 1/2 | .015" | 1/2 | .005" | 1 |
| 4000 RPM. | 35 | 148 | .033" | | .033" | | .018" | | .007" | 1 |
| 5.6" Boost. | 40 | 146.6 | .040" | | .040" | | .022" | | .010" | 1/2 & 1 |
| | 45 | 141.4 | .050" | | .050" | | | | .007" | 1/2 |

| | BOOST. ("Hg.) | B.M.E.P. | plug | Insert. | Centre of head. | Head flange. | Crankcase. |
|---|---|---|---|---|---|---|---|
| BOOST RESPONSE | 6 | 151.5 | .023" | | .025" | | .013" | | .003" | 1 |
| CURVE. RUN. | 8 | 162 | .025" | | .027" | | .014" | | .004" | 1 |
| | 10 | 172.5 | .028" | 1/2 | .028" | 1/2 | .015" | 1/2 | .005" | 1 |
| 3920 RPM. | 12 | 185.2 | .030" | | .030" | | .017" | | .005" | 1 |
| | 14 | 191.2 | .036" | | .036" | | .019" | | .006" | 1 |
| | 16 | 206.5 | .041" | | .042" | | | | .007" | 1/2 |
  
  
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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