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).
Cold-weather starting performance, proposing refrigerator tests to analyze power loss and oil viscosity effects.
| Identifier | ExFiles\Box 168b\2\ img052 | |
| Date | 11th May 1920 | |
| -3- Contd. OY1-G 16721. Although we were not able to take accurate records of current consumption, all our experiences on cold cars last winter with the R-R starter motor, Bijur and Westinghouse, go to show that the above figures are not far from the truth. The standard testing temperature for starting apparatus in this country is 10° above zero Fahrenheit, and since Rolls-Royce cars meet these temperatures in other parts of the world as well as the United States, we suggest that tests should be made in a refrigerator house in which the car has been allowed to cool overnight, to determine how the engine would start at freezing temperatures, and more particularly what were the figures for amps. consumed, terminal volts, with various types of batteries and starter cables. From this, and the known characteristics of the starter motor, it would be possible to find the various power losses by eliminating them, for example holding the clutch out to determine loss in transmission, running the oil out of the gear box and replacing with machine oil, to find the effect of viscosity of oil in the gear box. From viscosity curves of the oils used it would then be possible to form a fairly accurate estimate of the losses at low temperatures, say 10°F.{Mr Friese} We would suggest that this is of very great importance to us here, and also to Derby, in determining beforehand the probable behaviour in wintertime of English cars imported into Canada and elsewhere where cold winter conditions prevail. Rolls-Royce cars at present in Canada are not run in Wintertime, as far as we can ascertain, because of starting difficulties. Even the American cars which nearly all fit large batteries on the basis of 1 ampere hour per 5 cu. ins. of displacement, and motors which normally turn the engines at 100 r.p.m. or more, with chokers on the carburetters, and induction pipes which get hot almost at once, are felt by the Canadians to be difficult to start in winter, and to require further improvement. It should be remembered that in Canada, though the gasoline is better than in the States, the winter temperatures run to 40 below zero. Yours truly, ROLLS-ROYCE OF AMERICA, Inc. MO/G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Inc. (2 curves). | ||