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).
Findings from visits to Cadillac and G.M. regarding tyre noise, engine options, and gearbox design.
| Identifier | ExFiles\Box 173\4\ img107 | |
| Date | 7th December 1935 | |
| To Sg.{Arthur F. Sidgreaves - MD} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Hdy.{William Hardy} c. to RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}3/WJ. 7.12.35. The following is a copy of a memo received from Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} in America, dated 23.11.35. I spent Thursday at Cadillac and G.M. Building. Oy. showed us various experiments on tyre noise on a car suffering from this trouble. In all cases rubber between the wheels and frame is the best cure. The tyre people say torque tube cars are not so bad as Hotchkiss drive. Chevrolet use 1/4" rubber compressed to 1/10 between the rear axle and springs, the rubber also surrounding the dowel location. As well as dealing with tyre noise this increased the % of passable axles from 40 odd to 97 and helps suspension silence on rough roads. For front tyre noise they are using rubber between the spring and lower wishbone and also rubber insulating the anchorage of the top wishbone to the frame. I also had a further short talk with the Cadillac engine people. The V.8 I had tried is 3 3/4 x 4 1/2 about 5.7 litres. Oy. thinks if you do want an engine it would be cheaper and certainly much quicker to buy a car to which would be attached drawings of the new flywheel. Cadillac and others are draining the lowest point of the down draught induction system by a pipe going down to the undertray and ending in a ball valve so that the mixture is not weakened for cold starting. They say that the link belt is better than the morse chain for continued high speeds and needs no tensioning drive. Hence my addition to one of Da{Bernard Day - Chassis Design}'s cables to E.{Mr Elliott - Chief Engineer} for drawings for them to make us a chain. Yesterday we spent all day at the G.M. Building and talked to Thompson about chunking. He is of the opinion that the trouble is accumulated backlash. Therefore an integral side shaft would help. Also from the noise point of view a cast iron box and solid gears would help. In particular he criticised our square splines which bed on the bottom as well as the sides. He says these only touch in one place and have not sufficient oil cushioning. Possibly our end loading of the shafts did not stop the gears shifting under torque reversal. His recommendations are - (1) 10 pitch splines of twenty pitch addendum bedding on the sides only. To get a good fit the shaft should be soft | ||