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).
Technical report on brake mechanism clanking and exhaust banging issues.
| Identifier | ExFiles\Box 41\4\ Scan060 | |
| Date | 8th August 1927 guessed | |
| contd :- -2- (2) X.8420 BRAKE MECHANISM. Regarding the clanking in the brake mechanism, the only shock we know of is one occurring when the brakes are suddenly applied, and the servo is made to act powerfully and suddenly on the brakes. This appears to have been largely eliminated by the spring trust we have added to the servo adjust-ment, thus slightly reducing the speed that it is possible to apply to the brakes. There is however another noise caused by the flapping of the wire ropes on a very rough road. This makes a knock between the brake lever and the axle. It does not occur in England, but it does occur in France. It is cured by a rubber pad between the axle and the brake lever. (3) X.3692 BANGING IN EXHAUST. X.8240 CANCELLING THE GOVERNOR. If this is done our 20 HP. has the scheme we should recommend you to use on the Phantom - that is - the accelerator pedal is entirely independent of the hand control. The hand control can only open the throttle the same small amount as we do with a governor. In use we find that the best test for firing in the exhaust is to open the cutout, and the best way of prevent-ing firing in the exhaust is by the use of a well fitting and completely closing throttle. The hand control is capable of giving quite good results in skilful hands, but it is necessary when running fast on open country roads to put the throttle control well open, or let it completely close. To make the engine fire badly in the exhaust it is only necessary to open the throttle a slight amount. This slight amount at slow speeds will permit the engine to go on firing, but at high speeds the attenuated gas in the cyls. make the combustion irregular or so slow that much gas passes into the exhaust pipe to be fired there. If the throttle is still further opened ignition will go on all the time in the cyls, and no bang-ing in the exhaust will be apparent. If however the road permits of a still higher engine speed this partially opened throttle will cause very vigorous banging in the exhaust. The final result is that for entirely eliminating firing in the exhaust, and to enable the car to luff up satis-factorily without the use of brakes a closed throttle is the only solution we know, and this is how we drive. Whether it is brought about by the agency of the governor, or by the hands is a matter which you can choose, but our own impression is that the governor control does in many ways help the amateur driver, providing it, and the throttle are well fitted. It helps in the following ways contd :- | ||