Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Performance graph for a 10 EX aluminium engine with a 4.95-1 compression ratio, plotting BHP against RPM and MPH.

Identifier  ExFiles\Box 29\3\  Scan167
Date  7th September 1927
  
10 EX. ALUM. ENGINE COMP. RAT. 4.95-1
STANDARD INDUCTION AND EXHAUST
LONG DURATION CAMSHAFT
TURBULENT HEAD

B.H.P.
ENGINE R.P.M.
16 TOOTH M.P.H.
17 TOOTH M.P.H.

Graph Curves:
B.H.P. C.O. OPEN
ROAD WHEEL H.P. C.O. OPEN

Table 1:
ROAD SPEED ENGINE REV.
M.P.H. 16x52 17x52
80 2600 2450
70 2278 2140
60 1950 1835
50 1670 1580
40 1310 1228
30 978 920
20 653 613

Table 2:
AVERAGE PRODUCTION
FIGURE. % LOSS TO
ROAD WHEELS.
2750 38%
2500 28%
2250 22%
2000 22%
1500 20%
500 15%

Table 3:
AS ABOVE LOSS AT
VARIOUS ROAD SPEEDS
M.P.H. % LOSS
80 35%
70 27%
60 22.5%

Table 4:
DIFFERENCE IN H.P.
AT ROAD WHEELS
AVAILABLE
16 & 17 TOOTH AXLE.
M.P.H. % GAIN 17x52
90 10.5%
80 4.5%
70 2%

Stamp:
ROLLS-ROYCE LIMITED
SAINT ROOK.
7 SEP 1927
DERBY
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙