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 performance, bearings, tappets, and other automotive components.
| Identifier | ExFiles\Box 150\1\ scan0155 | |
| Date | 30th July 1936 | |
| To W.A.Robotham Esq. (Messrs. Rolls-Royce Ltd.) 2. DATE 30-7-36 temperature, taken between the pump and the bearings, exceeds 250°F (121°C) and, particularly if solvent treated oils are used which have corrosive tendencies. Some of these oils appear to form corrosive compounds and most of the oil people in the States are using inhibitors in order to avoid this trouble. So far as I can gather, when a corrosive oil is used with cadmium bearings the use of leaded fuel appears to aggravate the trouble, but if the oil is not corrosive, and if the oil in temperature does not exceed about 120°C, no trouble need be anticipated. At our laboratory we measured the oil in temperature of the Pontiac car under summer conditions and found it to be 305°F! With regard to lead bronze bearings, it has been definitely proved that the use of leaded fuel in the presence of solvent treated lubricating oil which is corrosive is beneficial and allays bearing trouble. If, however, an inhibited oil is used, no trouble is experienced and the use of a leaded fuel makes little or no difference. I am attaching herewith a dissertation from Major Hallett of G.M. Research, on Suspension. Probably there is nothing new in this so far as you are concerned, but I thought you might like to have it. I had a talk with G.M. Research on the question of measuring lubricating oil consumption under various running conditions, and they have a scheme which, over hundreds of tests, seems to be quite satisfactory. They run an engine at the duty desired, or at any rate at some specified load, until all temperatures are stabilised. They then drain the sump for a given time, weigh the oil and put it back in the sump. The engine is then run at the load or conditions desired for a given time, or equivalent mileage, after which the sump is again drained for exactly the same period and the oil is weighed. While I understood from you when I last saw you that you were not now so keen on the hydraulic tappet, the following information may be of interest. The Wilcox-Rich tappet (so-called Halford) has been quite successful and is used on the Cadillac 60 model and also the Pierce Arrow. The G.M. tappet is used on all the G.M. truck engines, which include all those fitted in motor 'buses. The engines include the following models: 468 (now out of production), 525, 616 and 707 cubic inches. On the quiet, I think Chrysler's are still playing about with the fluid fly wheel, but there is a hang up due to the fact that there appears to be some bother concerning the patent situation between Daimler's and Sinclair. I am also attaching herewith some photostats of blue prints of tests done in our laboratory on a supercharged Buick engine, and some work which shows the relationship between exhaust valve and exhaust gas temperatures, done on the same engine. | ||