Analysis of engine vibration issues, referencing compression, carbon deposits, and piston ring efficiency.
| Identifier | ExFiles\Box 3\1\ 01-page092 | |
| Date | 19th August 1913 guessed | |
| only normal and hardly sufficient to increase the compression from a capacity point of view. The original compression of this car was 66 lbs. Mr.Hives has informed me which is a little higher than our ordinary L-W type compression. The compressions, however, as regards holding the gas, were exceptionally good, and hence I should say, would account for the extra vigorous explosions. Also, the efficiency of the piston rings as regards holding the gases, generally improves with running. I also find that the formation of carbondeposit (especially noticeable when one uses the intermediate plug) causes the engine to be more hard running, and I do not think it is due to the fact of the compression increasing so much as to the fact that the explosions are more rapid and vigorous, due to there being less cooling effect on the gases. This, I think, would quite easily account for the development of the excessive vibration, if the vibration to which I refer is the one about which Mr.Royce is complaining. This is the experience I have with new cars and those which have been well run. 3. - It is a point which Mr.Royce has raised previously, but I do not think has been definitely proved. It would appear from this visit that Mr.Royce's complaint is as above. 4. - Except for a very slight retard vibration at about 20 M.P.H. on the speedometer there was a remarkable absence from vibrations in the "drive" of this car (which one usually gets on the ordinary standard car fitted with the solid engine coupling and standard pistons and connecting rods, and foot-brake drum behind gear box). 5. - I thought the slipper drive was working quite satisfactorily. | ||
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).