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).
Engine oil pressure issues, modifications to the cylinder head, and engine pinking.
| Identifier | ExFiles\Box 146\2\ scan0136 | |
| Date | 17th March 1937 guessed | |
| Sr3/ET.I.2.37 - 2 - I admit I was using Mobiloil Arctic, but I do not think this has anything to do with it. The problem therefore seems to be, when we have the Hall's Metal N°7 in position, how to keep our oil pressure up to 30 or 35 pounds, which I understand is what we are looking for. On the other hand, does the reading on the oil gauge really give us a true picture of what is going on in the sump. Once one has drilled the crankshaft and grooved the bearings. I presume that there is a tremendous flow of oil at these points, which reduces the pressure proper; if this is the case, probably the reduced oil pressure is only an optical disappointment, in other words one always prefers to see a decent oil pressure! I should like to have your views on this, which I consider an important point. Incidentally, you will be glad to hear that, as we expected this accident, we prepared a Hall's metal N°7, which is ready to be slipped in and we will therefore not have to take the engine out, etc.. Another point of interest is that, since carrying out the modification to the cylinder head, i.e. plugging up the rear water gaps, the temperature of my car has gone down approximately 12°. In fact, I now find very difficult to get more than 70° of temperature, in spite of having altered the setting of the radiator shutters. This, as you are aware, is not enough. I think also that this modification carried out on Bentleys would help us with certain complaints of pinking. What to you think? Needless to say we have done everything we know to my oil pump, to increase the pressure, but whereas George was successful in getting his pressure back to 40 pounds, we are not successful, presumably because we have Hall's metal instead of white metal clearances. Sr. | ||