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).
Key sheet defining the new 5-point measurement procedure for Bentley 3 1/2 & 4 1/4 Litre cylinder bores.
| Identifier | ExFiles\Box 146\3\ scan0108 | |
| Date | 15th October 1936 | |
| BENTLEY 3 1/2 & 4 1/4 L. CYLINDERS. FOR. RM.{William Robotham - Chief Engineer} Levallois Sr/VA2/ET.15.10.36. CYLINDER BORE DIMENSIONS KEY SHEET -------------------------- Measurements are now taken by us in 5 places in the cylinder bore, as specially requested by GWH.{George W. Hancock - Head Chateauroux} The 5 places measured have been taken at "AA{D. Abbot-Anderson}" - right angles to the crankshaft - and "BB" - parallel to the crankshaft, equaling 10 measurements in all. 1. "AA{D. Abbot-Anderson}" & "BB" measurement taken .500" from face of mouth upwards. 2. " " " " " 2.250" " " " " " 3. " " " " " 3.500" " " " " " 4. " " " " " 5.250" " " " " " 5. " " " " " .3125" " " "Crown" downwards. Upon reference to our standard sheet of "Report upon condition of cylinders" (Cylinder bore dimensions), a copy of which we attach, the above mentioned Nos. 1 & 2 measurements will figure in that part of the sheet reserved for the "mouth" dimensions. N°3 measurements will figure in the "Centre" and Nos. 4 & 5 measurements will figure in the "Crown". Please refer to sketch below, showing position of the five measurements, as mentioned above. In the past, we have only measured cylinder bores in 3 "AA{D. Abbot-Anderson}" and "BB" places, viz. .500" from face of mouth, and Centre of bore or 3.800" from "Crown" downwards, and at .500" from "Crown" downwards. Cs/VA | ||