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).
Adjustments and tests for steering, cooling, carburettor backfire, and oil pump leakage.
| Identifier | ExFiles\Box 5a\2\ 02-page147 | |
| Date | 8th July 1929 | |
| To H.R. From G.S.H. Hôtel de France, Châteauroux, Indre. 8/7/29. We have carried out further tests with the steering to-day and have now got what we consider the best combination of the cross steering tube and side steering tube. The steering is absolutely selective, joggles have been much decreased. There are of a high velocity, but one cannot call them objectionable. The oscillation of the steering wheel is not more than 1". The peculiarity of the joggles is that they are periodical with the front axle, we get the whole of the front of the car in a period of rapid oscillation, but one has to watch close to see the front in this period. It goes at a very high speed and is transmitted throughout the car. You can feel it through the seats as well as on the steering wheel. The load taken at the periphery of the steering wheel as now set is 11 1/2 lbs. We have fitted 2 .010" washers behind either spring on the cross steering tube. On the side steering tube the front end, we have increased the normal set up of the spring by .0613". At the pendulum lever end, we have increased the poundage of the spring by fitting a .125" washer on either spring, also increased the normal load by fitting a .0635" washer. We will measure the actual poundage and let you have it at our earliest convenience. We have also to-day carried out a test with the fan placed nearer to the radiator. In your letter you state that you had placed it to within .625" of the matrix. We do not understand how you have managed this, as we can only get .750". We cannot agree with you with regard to this not producing an objectionable noise. We have a distinct hum which can be heard as the car is driven along the road, and the noise would be taken objection to by Sales. The cooling efficiency we have not taken sufficient tests to give definite results. From what we have taken, we would surmise that we have dropped the temperature down 5°C. To-day, whilst the various changeovers were being made, I took the opportunity to dismantle the carburettor to ascertain the cause of the continual back fires on the over-run. I found that the jointing which had been used to make the joint of the carburettor to the body had run through on to the edge of the throttle, preventing it from entirely closing. There was also a hard mark, where the throttle appeared to be binding slightly on the side. Since I attended to this, we have had no further back fires in the silencer. Now the car is standard in this respect as the other S.S. cars. Re bijur oil pump. We can now definitely state that we have cured the oil leak from the pump by our methods as described to you. We have kept the level of the oil up to 1.125" from the top. NrCo G4. | ||