Rolls-Royce Archives
         « Prev  Box Series  Next »        

Engine performance comparing different camshafts, compression ratios, and ignition settings.


Identifier  ExFiles\Box 5a\5\  05-page114
Date  26th April 1934
  
-2-
(with 5.75 C.R.) shows a marked increase in power over the
standard engine at speeds above 3200 R.P.M.
From the point of view of detonations, the
112° shaft in the 5.75 C.R. engine is noticeably worse than
standard; but if the ignition is slightly retarded, so as
to effect a drop in power of not more than 3%, this engine
becomes slightly better than standard in this respect. The
ignition setting for these conditions is 10° before T.D.C.
when the hand control is in the fully advanced position.
It is suggested that an engine similar to the
above should be tried in a car, as the increase B.H.P. above
3000 R.P.M. should noticeably improve the acceleration at
that point.
The 116° camshaft (having the same long
duration cam as the 112° shaft) has been tested on the 5.75
compression ratio engine; a power curve of which will also
be found on V.501.
The effect of testing these camshafts with
the same compression ratio is indicated on curve V.751.

He/HP.
  
  
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 🗙