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).
Oil cooling systems, comparing existing designs and proposing a new manufacturing method for baffled tubes.
| Identifier | ExFiles\Box 173\1\ img227 | |
| Date | 19th January 1934 guessed | |
| 3 on it, today any type going into production must last 24 hours. OIL COOLING: The Corporation's first paper on this was printed in the S.A.E. Journal of April 1931; I missed it as we were not in trouble at that time. The oil cooler we got from Buick's was much on the lines of the paper, and is still their standard production. If you will get hold of the S.A.E. number you will see the BTU's they can deal with, and compare them with our results. My own feeling is that, on the 12 cyl., if we carry the water as far down the cyl. barrels as we can (on one engine Harrison's found that the oil ran 40°F.{Mr Friese} cooler when this was done) use a fully balanced shaft, and keep the journal and pin dias. from being excessively great, with kelmit or dural big ends, we shall be able to get away with an oil cooler of exceedingly modest dimensions, which will be more of a warmer than a cooler - in fact for European conditions might be dispensed with. As you know I am running on Mobile A to get easy starting, (See S.A.E. paper previously referred to), but the consumption is less than 700 M.P.G. at 40 M.P.H. average so that indicates that this oil is too thin for anything except zero use. Harrison's latest development on oil coolers is to evolve an oval tube fitted with baffles which the water surrounds, and the oil being passed through it, tubes being arranged in parallel. The tubes are manufactured by taking a rectangular slab of solder, say 1" x .250, and drilling holes in it where found most efficacious. The solder slab is made the required tube length and then nickel-plated to any desired thickness. When the solder is melted out a baffled tube remains, much stronger than a drawn tube, and on account of the additional turbulence given by the baffles, twice as efficient per unit area. I have samples of this. It would appear to be ideal for our purpose. So far they are not in production with this. WATER WATER OIL | ||