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).
Visit to Austin and Daimler to observe their cylinder fine boring processes.
| Identifier | ExFiles\Box 27\2\ Scan247 | |
| Date | 5th July 1934 | |
| X 1775 To Sft.{Mr Swift} and Worr from Sft.{Mr Swift} c. Hs.{Lord Ernest Hives - Chair} E.{Mr Elliott - Chief Engineer} B. Wor.{Arthur Wormald - General Works Manager} S/Ism. Sft{Mr Swift}2/BH.5.7.34. FINE BORING OF CYLINDERS. VISIT TO AUSTIN AND DAIMLER OF E.{Mr Elliott - Chief Engineer} & SFT.{Mr Swift} At Austin we were received by Mr. Armitage and were taken to the Dept. where Cylinder Fine Boring was in progress. Here we saw 6 machines (one Krausse and 5 Austin) in operation. These were running at different speeds and feeds, from 370 to 450 r.p.m. and from .002 to .004 feed per rev., varying according to the type of block in operation. The results obtained at Austin were particularly good, some examples were measured by the Solex Pneumatic Micrometer. This Instrument is an extremely accurate means of taking measurement, with or without mechanical contact, and the measuring of Cylinders is one for which this type of Instrument is especially suitable, and the results showed that for size, parallelism, and cylindricity, the bores were definitely held to a limit of 1 1/2 tenths of thousands, and the finish, with a feed of .002 was exceptionally good (considerably better than the experimental sets machined for us by Krausse). Austin have further improved this by a short lapping operation with a special Piston. As mentioned in E's report, on one type the fine boring was done with a dummy head bolted in position, and they admitted that this had given them improved machining results on this particular type. We both felt that where possible, it is advisable to do fine boring with the head bolted to the block. At Daimler they have only one machine. This is a Krause. We were able to see many examples of their fine boring, and the general impression formed was that the results were of a slightly lower standard than that of Austin. This was confirmed when one was measured at our request. Here again the measuring was done with the Solex equipment, which Daimler have installed quite recently. The finish was decidedly rougher, due I suggest, to the slightly different type of tool, and to the coarser feed employed. The Solex measuring device showed that the results obtained at Daimler were approximately 1 1/2 tenths of a thousand worse than the limits worked to at Austin, and further Daimler do not lap after boring, and claim that they are quite satisfied as regards ring wear. | ||