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).
Issues with one-shot lubrication, rear shock dampers, and cooling system performance.
| Identifier | ExFiles\Box 5a\2\ 02-page140 | |
| Date | 1st July 1929 guessed | |
| -2- We do not like the general layout of the one shot lubrication. On the car supplied by the pump, 75% of the connections are on the o/s pipe lines from the pump, and we have found by observation that more oil passes through the pipe lines on the n/s than on the o/s. We have had great difficulties in obtaining sufficient supply on the o/s to feed the correct amount of drops per stroke of the pump to the o/s rear shock-damper. Actually we have had to fit an S.2 bijur which on the chart should be passing 30 drops per stroke but in position does not pass more than 15. We think it would be more preferable if the branch pipes were better balanced out, equalizing as far as possible the supplies from either side. Another feature which we think would be improved is that the main feed pipes from the pump should be carried back half way up the chassis, so that the heat from the engine would not affect the flow of oil to the extent that it does, in so much that there are a lot of junctions and supplies beneath the bonnet which must be twice the heat of the other parts of the chassis, thus making the oil flow freer to these parts. The question of feeding the rear shock damper connecting links would we think be advantage & if bijurs supplying them could be fitted at the extreme end of the arm instead of on the damper as at present, the reason being the position of the arm in normal running conditions is at an acute angle above that of the damper, which means that after the oil has passed the bijur pressure must still be maintained to get the oil up the arm and to feed the ball ends. But as we have a definite back pressure or sluggishness of oil the wrong side of the bijur. We should not take objection to this only that the arms are in a constant draught of cool air, which naturally must congeal the oil considerably. We understood that the bijur oil pumps were now giving a pressure of approx. 100 lbs. We have not had any instrument to verify this, but we should very definitely say that on the pipe lines of this car, there is nothing approaching the 100 lbs. pressure. We should be very pleased to hear from you after the car has returned to England whether this is so or not. Please note the rear o/s shock damper lug was broken off while testing same on the bench. It has in no way interfered with the working of the shock damper, and we have made a suitable bracket to hold the damper in position. We draw your attention to this to prevent any misunderstanding as to the cause of the lug being off. Since writing the above, as the car was finished I have been able to go out and take a temperature test with the fan close up to the matrix. The results are very disappointing. Firstly, the noise from the fan is most objectionable and would not be tolerated for a moment. Secondly there is no improvement in the cooling effect, in fact we should not be above saying that it is worse. | ||