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).
20-HP car testing issues, including crankcase pressure, oil leaks from the fan pulley and rocker cover, and steering problems.
| Identifier | ExFiles\Box 5a\2\ 02-page222 | |
| Date | 18th March 1930 guessed | |
| -2- of the silencer on the 20-HP. This is the aluminum covering which has always failed and which we have continually reported upon. The same conditions have arisen with the present car. We are again in trouble with too much engine crankcase pressure, after having done approx. 5,000 miles. This pressure causes the oil to flow freely out of the orifice round the fan pulley. We can immediately stop it by taking off the cap of the oil filler, which then releases the pressure. We found that the closeness of the fan pulley to the engine case causes a suction of air which draws out the oil. If the fan pulley is taken off, there is practically no oil forced out, but immediately the fan pulley is refitted oil streams out. We proved this by packing the fan pulley 1/2" from the crankcase, which had the same effect. It was a 90% cure, and by fitting two vanes on to the timing case at an angle of approx. 60°, these vanes to break up the flow of air, we cured the oil flow entirely. This is experimental data to work upon, as we could not run the car on the road without moving the fan and getting longer studs for the fan pulley. It may be interesting if you could forward this on for Mr. Elliott's information. Our method of stopping oil coming out of the rear bearing of the crankcase has been a 90% job. We get a few drops of oil, but not more than a few drops out of the rear bearing. There has been no definite flow of oil as previously experienced during our 10,000 miles tests. It is quite probable that with some other slight modifications, which probably Mr. Elliott could foresee, the oil jet could be a 100% job. We are watching very closely the clearance of the valves to try and obtain some data for their failure. Up to now, we have not anything definite to report. You will see, in to-day's Daily Report, a note on the steering becoming sluggish. We have found this to be due to the front ball end of the steering tube having become dry through the failure of the Bijur plug supplying the oil to same. The front axle has been regularly oiled every 500 miles. No other parts of the axle appear to be suffering from shortage of oil. We have been continually reporting throughout this trip on the leak of oil from the rocker cover. This has on some days been very bad, and we should recommend that the Phantom scheme of rocker cover should be adapted to the 20-HP. We shall continue to run experimentally until we receive your letter. G.E.B. [Illegible Signature] | ||