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).
Notes on the design and manufacturing of various car components including wheel rims, axles, petrol tanks, and frames.
| Identifier | ExFiles\Box 127\4\ scan0163 | |
| Date | 27th July 1939 | |
| -2- Rml/R.27.7.39. wheel rims. Oy. states that Kelsey Hayes make the best wheel rims. They are now getting a wheel for the 14 h.p. car for 13 lbs weight. They are using 9" drums by 1 3/4" width on all their models except the 25/30. They find the Lepaz drum, made by Leys Malleable, to be the best. To get durability, they find it is essential to bolt the wheel on to flat faces. Rear Axles. Their dif. boxes both for trucks and the other models are malleable cast iron. Oy. states that a 7" crown wheel will stand up to their 20 h.p. engine, the only limiting size on the smaller jobs being the differential. The front axle goes down to a 5 tooth pinion to a 41 tooth crown wheel. Tool Kits. American tool kits have now got down to one pair of gas pliers, a screw driver and a jack. Petrol Tanks. Standard English practice is to use material .040" thick, standard American practice is to use material .025 thick corrugated to prevent drumming. The result of this is that the Chevrolet 12 gallon tank is 1.27 lbs/gall. The Ford and Vauxhall 10 gallon tank made in England is 2.1. Oy. states in their opinion the thin tank is quite satisfactory. Oy. states that to get the true stiffness from a box frame it is necessary to weld every inch. Their biggest difficulty with a monocoque construction is to get the insurance people to insure the car. They think the best idea is to compromise. No frame beneath the body, but a frame bolted on the front to carry the power plant. | ||