Rolls-Royce Archives
         « Prev  Box Series  Next »        

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).
Joint wear, drip plug failures, and overall lubrication performance after testing.

Identifier  ExFiles\Box 11\2\  02-page076
Date  21th January 1929 guessed
  
-4-

78

As reported on front axle, we found several joints when disconnected, the solder had cracked but had not leaked oil. It would appear that solder is not strong enough for the joints. We should also point out that the aluminium washers are not satisfactory for the joints, the material is too soft and gives way after the joints have been tightened up and allow a weep of oil. We reported this on 12-EX six months ago. Re the ball end on pendulum lever, although this has been well lubricated, a considerable amount of wear has taken place where the pads are in contact. The springs were not quite in tension, there being .005" slack. This may have caused a chatter to take place with a consequent wear of the ball end. The ball end is not soft. Re the wear that has taken place on the front spring rear anchorage pins, we are of the opinion that the bearing surface of these pins is too small for the load they have to take, and that an increased bearing surface would be beneficial. They have been well oiled. We suggest that all shackle pins and anchorages should have the drops per min. increased to 8 or 10 per min. The figures given in the column drops per min. before test are on the chart and should not be taken as absolutely correct. We find that no two Bijurs are alike when new and they will have to be definitely checked with a low temperature of oil. The chart numbers of the Bijurs we find are not correct per drops per min. with out spare plugs.

The trouble of a failure in a drip plug is not caused by the felt packing getting choked, but by the plunger partially seizing and not opening the valve. We have very carefully checked the working of the Bijue drip plugs and can now alter the drops per min. at will. The plunger and guide dominates the rate of oil flow. The diameter of the plunger is standard, the guide or hole for the plunger is increased or decreased for the rate of flow. In the case of a drip plug allowing only one to two drops per min., the plunger is very liable to stick and not open the valve sufficiently to give the necessary drops per min. To rectify this, the plunger is smoothed down. The symptoms are exactly the same as valve stems in the oil release valve, you can see hard marks on the plunger. To take the plug to pieces, the end plug cap (brass) can easily be taken out by using the jaw of a magneto contact spanner, the spring will then follow, then the brass disc i.e. valve, and a very fine mica washer, after this washer the plunger can be tapped out (if oily). To examine the filter it is necessary to drill a .1875" hole through the blank end, insert a pin and the felt can be withdrawn.

The general lubrication of the car is very good and with the alterations to drip plugs as reported, there should be no trouble with lubrication. The non-oiled parts such as brake rod and rope pins should be covered with a felt wrapping soaked in oil. These parts do not get oiled and they are generally the most exposed to water and dirt. We have used Ford Mobiloil for the latter part of the test and find it the most suitable we know of over here. We suggest that 2 strokes of the pump be used every 200 miles, the same applying to the oiling of the front and rear axle, i.e. 200 miles. The propeller shaft joints do not show the slightest signs of wear. The loss of oil for the last 5.000 miles is very small, i.e. a third of a syringe. The joints hold 3 syringe fuls. It would not have been necessary to add any oil to the joints during the test, but we did so to get a definite figure of oil consumed or lost in the joints. We are dismantling the engine and will report as soon as possible.
  
  


Copyright Sustain 2025, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙