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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).
Engine test data sheet for engine PII-21, detailing power curve, pressures, and timing.

Identifier  ExFiles\Box 19\3\  Scan238
Date  27th March 1930
  
ENGINE N.o: PII-21 TYPE: Left Handed
DATE COMPLETED TEST: 27-3-30
DATE REC'D ON TEST: 26-3-30
HOURS RUN DURING TEST: 5
CLEARANCE VOLUME: N.o 1 CYL.: ___ CU. INS., N.o 6 CYL.: ___ CU. INS.
AVERAGE COMPRESSION RATIO:
ROCKER CLEARANCE (COLD): INLETS = .006", EXHAUSTS = .006"
IGNITION TIMING: (HAND CONTROL FULLY ADVANCED.) MAGNETO = 15° BEFORE T.D.C. BATTERY = 15° BEFORE T.D.C.

POWER CURVE ETC. (Power & Compression Figures Corrected to N.T.P.) BAR. = 763 m/m.{Mr Moon / Mr Moore}

POWER CURVE TABLE:
R.P.M. | Corrected B.M.E.P | Corrected B.H.P. | PETROL CONSUMPTION (Actual PTS/HR, Specific PTS/BHP/HR) | DEPN IN MANIFOLD (INS Hg) | POSITION OF MIX. CONTROL | COMPRESSION PRESSURE (LBS PER SQ. IN.) (1, 2, 3, 4, 5, 6, AVERAGE)
3250 | - | -
3000 | 62.0 | 110.0
2750 | 71.5 | 116.2 | | | | 86.0
2500 | 78.3 | 115.7 | | | | 86.0
2250 | 82.5 | 109.7 | | | | 87.5
2000 | 87.0 | 103.0 | | | | 89.0
1500 | 92.7 | 82.2 | | | | 86.0
1000 | 93.7 | 55.5 | | | | 82.0
750 | 94.5 | 41.4 | | | | 83.0
640 | 97.3 | 36.8

DISTRIBUTION TEST:
R.P.M. | LOAD WITH SIX CYLS. FIRING | LOAD WITH FIVE CYLINDERS FIRING (1. OUT, 2. OUT, 3. OUT, 4. OUT, 5. OUT, 6. OUT) | AV. LOAD DROP PER CYLINDER
2500 |
1000 |

OIL PRESSURES. (LBS PER SQ. IN.):
R.P.M. | MAIN | INTMD | LOW | OIL TEMP
2500 | 65 to 70 pressure
1500 | at... temperature
500 |

VALVE TIMING:
| .020 CLCE | N.o1 CYLINDER | N.o6 CYLINDER
INLET OPENS | 10½° AFTER T.D.C. | AFTER T.D.C.
INLET CLOSES | 46½° AFTER B.D.C. | AFTER B.D.C.
EXHAUST OPENS | 47° BEFORE B.D.C. | BEFORE B.D.C.
EXHAUST CLOSES | 4° after T.D.C. | T.D.C.

DETONATIONS. (FULL THROTTLE. WATER TEMP = 80°C)
SPEED AT WHICH DETONATIONS BECOME JUST AUDIBLE,
@ LISTENING CLOSE UP TO ENGINE = ____ R.P.M.
@ LISTENING EIGHT FEET FROM ENGINE = ____ R.P.M.

Timing Gears: Fairly free from any noise. Very slight rattle at low speed when off charge.
Oil Pump Gears: OK
Remarks: The above power curve was taken without hot spot (except at 640 RPM). A standard silencer was fitted but no fishtail. The ignition was set for max. power at each speed as the oil relay was not connected up. Engine very free.

SPECIAL PARTS FITTED.
SCHEME | DESCRIPTION

STAMP: R-R LTD, PAINT R, 13 DEC 1929, DERBY
  
  


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