Cost and weight comparison between an all-aluminium monoblock (J.III type) unit and an existing cast iron 20/25 unit.
| Identifier | ExFiles\Box 10\5\ 05-page017 | |
| Date | 14th May 1938 guessed | |
| 658 Hives 10LL COMPARISON ALL ALUM. MONOBLOCK (J.III TYPE) UNIT WITH EXISTING 20/25 UNIT. Sp. {Mr Spinney} Gr. {George Ratcliffe} Cast Iron 2.81 times that of Al. Cast Iron. Wt. of cylinder block. 62.5 Wt. of cylinder head. 73 Total weight C.I. @ 1d/lb. 135.5 Total cost of cast iron 11/3. Aluminium. Wt. of cylinder block. 22.2 Wt. of cylinder head. 26 Total wt. of aluminium @ 1/4 per/lb. 48 Total cost of Al. 64/-. Liners basically cannot be much more expensive than the cylinder bores they replace, otherwise how could the Wolsey Hornet fit them Rm. {William Robotham - Chief Engineer} | ||
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).