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).
Addition to a report on tests comparing the valving efficiency of Phantom and Bentley engines.
| Identifier | ExFiles\Box 106\5\ scan0111 | |
| Date | 25th September 1933 | |
| x 5060 x 7060 x 250 x 7497 To Wor.{Arthur Wormald - General Works Manager} from Hs{Lord Ernest Hives - Chair}/Std. P. C. R.{Sir Henry Royce} P. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Re. P. Dy.{F R Danby} PH. P. Da.{Bernard Day - Chassis Design} LR.{Mr Ellor} P. Bo. Hs{Lord Ernest Hives - Chair}/Std.6/KT.25.9.33. ADDITION TO REPORT OF TESTS ON EFFICIENCY OF VALVING OF PHANTOM & BENTLEY ENGINES. Since writing the above Report Hs{Lord Ernest Hives - Chair}/Std.11/ MA.24.6.33. we have made some attempts to analyse the reasons for the superiority of the 8 litre Bentley head over the Standard Phantom II design. The points likely to affect the volumetric efficiency in which the heads differed were :- (1) Number of valves per cylinder. (2) Length of induction ports. (3) Shape and curvature of induction ports. (4) Design of combustion chamber - Phantom turbulent, Bentley non-turbulent. Tests were carried out (with blower rig, in precisely the same manner as the previous ones) to determine how far these points did affect the volumetric effy. of the head. Tests carried out. (A) To investigate point (2) - the pressures at various points in the port (at A.{Mr Adams} B. C. - see diagram 1.) were measured for three different flows covering the top speed range (see attached table sheet 4.) (B) To investigate point (3) - air flow/press. differ- ence curves were taken with a special Phantom II large valve head (K.83906) section, sectioned horizontal through its inlet valve seat so that the inlet port could be rotated about the valve stem in a horizontal plane to any angle with centre line of combustion chamber (diagram 2.) Curves were taken with port arranged, (a) in normal position and (b) so that centrifugal action of air velocity tended to throw the air to the unrestricted side of the valve (see sheet 1.) | ||