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).
The cost and production challenges of the Aerolite Piston.
| Identifier | ExFiles\Box 87\2\ scan0142 | |
| Date | 28th February 1936 | |
| -3- (2) High Cost of the Aerolite Piston. Referring to the Standardisation Sheet No.236, it will be seen that on this sheet it is stated there is no difference in cost between the Aerolite piston and the R.R. piston. We have confirmed that this was so up to the introduction of the large bore, and so far we have seen no figures for the large bore engine, but in view of the figures on the small bore engine we can see no reason why the Aerolite piston, since its weight is now less than the fully split piston, should not cost less. (3) Difficulties of production. There was undoubtedly a considerable amount of trouble on the introduction of the Aerolite piston. We attributed the majority of this to our insisting, shortly before going into production, that the Aerolite piston should be made in R.R. 53 alloy. This was a material of which the Aerolite people had had no experience, and there was some difficulty initially over getting the correct heat treatment and limits. By, however, is of the opinion that we cannot blame the Light Production people for that. Now that production have become familiar with the product, however, we believe that they agree with our experimental experience which is that the Aerolite piston is slightly more sensitive to variation in tolerances or foreign matter than the split skirt type, in return for which it gives more power and consumes less oil. The above is, we think a fair summary of the present technical position as we see it, and actually to-day, although the matter is open to discussion, we consider that the Aerolite piston is the right one for the 4 1/4 litre Bentley. What concerns us, however, is the statements which have been made about this product that have no justification whatever. | ||