Rolls-Royce Archives
         « Prev  Box Series  Next »        

Comparative chart of 30 indicator diagrams for a 20 HP Rear component under various test conditions.


Identifier  WestWitteringFiles\V\December1930-February1931\  Scan088
Date  3rd January 1931 guessed
  
SHEET I

Col: I

Row 1:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. LIFT .010"
H.P. VALVE DRILLED .055" DIA.
450 R.P.M. 1" STROKE . 25°C.
Graph: 1.23 D", 54.6%

Row 2:
20 HP. REAR. 65/75 LB. HIGH PRESSURE.
.025" DIA. AIR VENT. LIFT .010"
H.P. VALVE DRILLED .055" DIA.
450 R.P.M. 1" STROKE. 25°C.
Graph: 1.45 D", 54.5%

Row 3:
20 HP. REAR. 65/75 LB. HIGH PRESSURE.
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .055" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.42 D", 72.9%

Row 4:
20 HP. REAR. 65/75 LB. LOW PRESSURE.
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .055" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 2.1 D", 53.1%

Row 5:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .055" DIA.
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.12 D", 78.2%

Row 6:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050
H.P. VALVE DRILLED .055" DIA.
70 R.P.M. 4" STROKE 25°C.
Graph: 3.46 D", 75.4%

Col: II

Row 1:
20 HP. REAR. 65/75 LB. LOW PRESSURE
AIR VENT BALL REMOVED. DAMPER FILLED TO STD. LEVEL.
450 R.P.M. 1" STROKE 25°C.
Graph: 1.17 D", 50%

Row 2:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
AIR VENT BALL REMOVED. DAMPER FILLED TO STD. LEVEL.
450 R.P.M. 1" STROKE 25°C.
Graph: 1.40 D", 50.2%

Row 3:
20 HP. REAR. 65/75 LB. LOW PRESSURE
AIR VENT BALL REMOVED. OIL LEVEL STANDARD
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 4.15 D", 86%

Row 4:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
AIR VENT BALL REMOVED. OIL LEVEL STANDARD
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.33 D", 85.5%

Row 5:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
AIR VENT BALL REMOVED. OIL LEVEL STANDARD.
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.71 D", 88.4%

Row 6:
20 HP. REAR. 65/75 LB. LOW PRESSURE
AIR VENT BALL REMOVED. OIL LEVEL STANDARD
70 R.P.M. 4" STROKE 25°C.
Graph: 4.07 D", 88.2%

Col: III

Row 1:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. LIFT .004"
H.P. VALVE DRILLED .032" DIA.
450 R.P.M. 1" STROKE. 25°C.
Graph: .87 D", 38.9%

Row 2:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. LIFT .004"
H.P. VALVE DRILLED .032" DIA.
450 R.P.M. 1" STROKE. 25°C.
Graph: 1.05 D", 39.3%

Row 3:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.07 D", 79.8%

Row 4:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.23 D", 69.5%

Row 5:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
70 R.P.M. 4" STROKE. 25°C.
Graph: 3.91 D", 82.7%

Row 6:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.46 D", 77.8%

Col: IV

Row 1:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STANDARD LIFT
H.P. VALVE DRILLED .032" DIA.
450 R.P.M. 1" STROKE 25°C.
Graph: 1.31 D", 55%

Row 2:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
STANDARD
H.P. VALVE DRILLED .032" DIA.
450 R.P.M. 1" STROKE. 25°C.
Graph: 1.24 D", 45.4%

Row 3:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.42 D", 84.4%

Row 4:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 4.05 D", 85%

Row 5:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
70 R.P.M. 4" STROKE. 25°C.
Graph: 5.39 D", 81%

Row 6:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE DRILLED .032" DIA.
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.46 D", 84%

Col: V

Row 1:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. LIFT .010"
NO HOLE IN H.P. VALVE
450 R.P.M. 1" STROKE. 25°C.
Graph: 1.01 D", 47.1%

Row 2:
20 HP. REAR. 65/75 LB. HIGH PRESSURE.
.025" DIA. AIR VENT. LIFT .010"
NO HOLE IN H.P. VALVE.
450 R.P.M. 1" STROKE. 25°C.
Graph: .99 D", 43%

Row 3:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE NOT DRILLED
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 3.48 D", 85.5%

Row 4:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE NOT DRILLED
130 R.P.M. 2 1/2" STROKE. 25°C.
Graph: 4.05 D", 86.0%

Row 5:
20 HP. REAR. 65/75 LB. LOW PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE NOT DRILLED
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.13 D", 90%

Row 6:
20 HP. REAR. 65/75 LB. HIGH PRESSURE
.025" DIA. AIR VENT. STD. LIFT .050"
H.P. VALVE NOT DRILLED
70 R.P.M. 4" STROKE. 25°C.
Graph: 4.84 D", 91.0%

Common Y-Axis Label for all graphs: 154 LB/D"
  
  
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).


Copyright Sustain 2026, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙