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).
Analysis comparing the performance of the Rudge, P.V.G., and Bentley single-cylinder engine units, focusing on estimated motoring losses.
| Identifier | ExFiles\Box 133\1\ scan0008 | |
| Date | 13th March 1936 guessed | |
| -3- General Remarks. In the following paragraphs, an attempt has been made to analyse the performance of the Rudge and to contrast it with the P.V.G. and the Bentley single cylinder units. Unfortunately, no motoring tests have been carried out on this unit, and these were thus estimated by the aid of curves in the report Hd{Mr Hayward/Mr Huddy}/Wd.{Mr Wood/Mr Whitehead}2/WJ.17.2.35 analysing the motoring losses in the Kestrel K.1025 main engine. The estimated curve is given in Fig.VIII, accompanied by a P.V.G. motoring curve, also partly estimated. Power curves for the two engines are shown in Fig. XIV, and the following additions are then made to the ordinates of the P.V.G. power curve at corresponding piston speeds :- (1) Correction for compression ratio, taken from test results on the Kestrel single. (2) Addition of the difference in motoring losses between the P.V.G. and the Rudge. (3) Addition for exhaust pipe ramming taken from report Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead}1/GB.14.6.35. Considering the very approximate nature of the investigation, the agreement is remarkably good, andit would appear that the only advantage of the Rudge is its low mechanical loss. This is borne out by the engine construction - all ball and roller bearings at big end and main bearings. For this comparison the Rudge timing was used as it seems to approximate more closely to the P.V.G. For the contrast between the Rudge and Bentley single, we take motoring losses for the latter from the report Hs{Lord Ernest Hives - Chair}/Wd.{Mr Wood/Mr Whitehead}/CHP.1/GB.1.11.34, these being the only figures available, and curves showing the difference in motoring losses are given in Fig.XVI. | ||