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).
Report from the U.S.A. on competitor developments in aluminium connecting rods, pistons, and clutches.
| Identifier | ExFiles\Box 178\2\ img180 | |
| Date | 19th February 1934 | |
| COPY OF REPORT RECEIVED FROM Ra. IN U.S.A. DATED 6.2.34. [Illegible distribution list, crossed out] c. to E.V. Hs{Lord Ernest Hives - Chair}/Ra.9/KW.19.2.34. [Stamped: RECEIVED 21 FEB 1934] ALUMINIUM CON. RODS. Cadillacs have run some of these made by the Bohn Aluminium Co. The original ones broke across the shoulder but at a second attempt they overcame the failure and have had no further trouble. They use steel caps. Rods have not done 3,000 miles. It is recorded that Franklins used aluminium rods direct on shaft and ran into trouble at 40° below zero the rods tightening on shaft. Cadillacs report that with strip lining 3/32" thick, this trouble is overcome (white metal or lead bronze .015 thick rest steel). If we can get or make strip bearings suggest that we should run these an endurance test. Bringing sample rod back. Average weight saving alleged over steel - 40%. PISTONS. Inverstrut pistons are rapidly losing ground to the T. slot all alum. piston anodically treated. Will bring samples back suitable for running on the Bentley or 20/25. CLUTCHES. Cadillacs are experimenting with the same long single plate clutch as Lincoln are using. They gave me the following figures - Facing 12 1/4 x 7 Pressure 1600 lbs. Pedal travel 4.00" Separation .050. Pedal pressure 26 lbs. Cushioning .030. The pedal pressure seems to be incredibly low compared with ours but the Americans put up with over 5" effective pedal travel. | ||