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).
Analysis of cylinder boring and honing methods, comparing production time and wear results.
| Identifier | ExFiles\Box 27\2\ Scan248 | |
| Date | 5th July 1934 | |
| -2- Sft{Mr Swift}2/BH.5.7.34. From a production cost point of view, I do not consider this method would show any appreciable economy. The operations which would be effected are the final reaming (now done on 6-spindle Machine) and honing of bores (Single spindle Machine operation) for a total time of 44 minutes actual. I estimate that with the Krause type fine boring machine, the time necessary for our Cylinders would be approximately 6 1/2 minutes per bore, i.e. a total time of 36 to 39 minutes actual time. Then we should require a further allowance for a short lapping operation, which I feel sure will be found necessary if minimum bore and ring wear is to be maintained. In support of this I quote an extract from my report Sft{Mr Swift}9/BH20.2.33, dealing with the bored Cylinders which had been done at our request by the Krause people, and tested out on a Unit Engine for the equivalent of 6,500 miles. The extract reads:- "These cylinders were inspected by Wor.{Arthur Wormald - General Works Manager}, Hy.{Tom Haldenby - Plant Engineer}, By.{R.W. Bailey - Chief Engineer}, and Sft.{Mr Swift}, and later by E.{Mr Elliott - Chief Engineer} and it was agreed that the evidence showed definitely that these Cylinders are inferior to our own finish, as regards wear of Cylinder bore and Piston Rings, and it was agreed no further action be taken for the present. Dimensions after testing:- Krause. R.R. Cyl. bore average wear - +.00125 Approx. nil. Ring wear - increased gap dim: Approx. average +.004 +.001. I was very impressed with the Austin methods and see no reason why we should not get better quality results than with our present methods, as especially with a short lapping operation, we could improve greatly on our previous effort. In addition, we are of the opinion that our Cylinder Inspection could be more adequately equipped for taking accurate and competitive measurements if we installed the Solex Pneumatic Micrometer. This could be installed in the Cylinder Inspection and no doubt would also be extremely valuable for other units. | ||