Tests for exhaust boom and steering, detailing faults found in the front axle, pivot pins and lubrication system.
| Identifier | ExFiles\Box 11\2\ 02-page287 | |
| Date | 23th July 1929 | |
| To Hs. {Lord Ernest Hives - Chair} From G.W.H. Hôtel de France, Châteauroux, Indre. 133 23/7/29. We yesterday tried out various tests for exhaust boom and steering. Re the exhaust boom, we tried various baffles but without much success. We also tried the difference with the snout on and off, the idea being that when the cut-out is open the booming is terrific, the reason being the very free inlet to the exhaust system. With the snout fitted, the in-rushing air on the retard is baffled, and it is to find out some data that we tried with and without the snout. We believe that if a cylindrical casing was fitted half way up the silencer making a further baffle, for the exhaust swan neck to be fitted on to it in its present position, we should obviate some of the booming effect. We were working on this line and were going to have one fitted. Whilst carrying out these tests, the steering became very unstable. To find the reason for this, we have dismantled the front axle and found one very definite fault with the ball ends on the steering arm. It is possible to fit the balls in the sockets with the oil holes at right angles to the pads; the oil then, instead of lubricating the pads, has a free outlet and no oil reaches the pads. This has happened on 21-EX, the consequence being that one end of the cross steering tube had partially seized. There should be very definitely some means of locating the balls in the sockets on the steering arm. We came up against a difficulty in getting the steering pin out of the o {Mr Oldham} /s pivot. The bush came half way out with the pin, then seized, and it was necessary to take the axle off the car and place it under a press to free the pin. It would seem that the boring of the front axle is not concentric with the bush when the bush is pressed into position. Friction of the pivot pins: in neither case of the o {Mr Oldham} /s or the n/s, is the area of the friction surface of the pivot pins more than 1/8 of its surface. This means that instead of getting the friction from our steering pivots that we should do, we are losing more than 80%. This is entirely a question of machining the faces correctly and should be very carefully watched. (Plan.) Re the side steering tube, we have noticed that the oil holes in the ball ends both of the steering arm and pendulum lever, are opposite the holes drilled up the shanks which retain the springs, consequently oil fed to the balls a considerable amount is lost by escaping through the spindles. To prevent this and to form a reservoir for feeding back, we have plugged up the far end of the spindle with cork. This would be quite an easy matter to do, and as stated would form a reservoir for oil. Cont'd.... | ||
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).