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).
Letter discussing engine performance issues, fuel detonation, and potential solutions involving throttle and shutter adjustments.
| Identifier | ExFiles\Box 75\2\ scan0265 | |
| Date | 23th August 1921 | |
| Contd. -3- It does provide a means of dealing with any kind of fuel if it is used intelligently. You will appreciate from the scheme that the weakness is that when the engine is pulling at full acceleration low speed, the exhaust heat to the throttle is rather low. We find the advantages are that in warming up the engine, if the hand control throttle is used, the shutter in the exhaust pipe is then shut right off and the throttle warms up exceedingly quickly. If we could only educate the driver to use the hand control for the first part of the running, it gives very excellent results. Another advantage in the shutter scheme is that you can, by altering the adjustment of the shutter, get a varying degree of heat on the throttle. We find we get the best results with rather a thick shutter and adjusted so that it is slightly over horizontal. This gives us a long dwell in relation to the accelerator. This adjustment, of course, can be altered still further so that one would imagine there could be a Winter and summer adjustment which would give the desired results. I do not agree with you when you say that the liquid petrol in the cylinder is likely to cause detonation. Take one of our own 40/50 chassis you will find that as you make the mixture stronger which must be as you increase the amount of liquid going into the cylinders, the detonation is reduced. On the other hand, take any paraffin engine which has a proper vapourizer on, to vapourize the liquid; this will always detonate. Ricardo has done more work on fuels than any other Authority. R.{Sir Henry Royce} and myself visited his Laboratory last year when he was in the middle of the tests. He does not confirm your argument. If the cure for detonation was as easy as you suggest, there would not be so many people working on the problem. I do not want you to think for one minute I do not appreciate your kindness in sending me copies of interesting U.S.A. journals - they are always very instructive and interesting. I feel, however, that if we are going to get anything done to overcome our own troubles, we must make sure we are not side-tracked by getting involved in problems which will not help us to get out of our immediate difficulties. Yours sincerely, HS.{Lord Ernest Hives - Chair} | ||