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).
Technical review of a Chrysler Red Head 72, focusing on its weight, gear ratio, and engine performance.
| Identifier | WestWitteringFiles\S\March1928-May1928\ Scan177 | |
| Date | 10th May 1928 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} BY.{R.W. Bailey - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/RmL/LG10.5.28. CHRYSLER RED HEAD 72. X4072 / Y3542 CAR WEIGHT. We tried one of these cars. It was fitted with a five-seater sedan body. We were surprised to find that the complete car weighed 30.5 cwts., this in spite of generous use of cast iron in crankcase, gearbox and rubber shackle mountings - bumpers front and rear. Weight seemed to be saved in the hubs, which were very diminutive, wheels which were wood and spares, as only one rim and tyre are carried. Also the front axle which seemed to be of simple tubular construction and very light. Otherwise it was difficult to see where large saving had been made. GEAR RATIO. The car top gear ratio is 4.3/1, it has small 30" tyres. The result is an engine speed nearer 3rd. than top gear of the 40/50. Actually the 40/50 ratio between top and 3rd. is 1 - 1.46, between the 40/50 and Chrysler top gear 1 - 1.32. ENGINE PERIODS AND TORQUE REACTION. The most remarkable feature of the car is that one would not suspect if of having 6/1 compression ratio except from its performance. There is little or no torque reaction and little engine roughness at high speeds. When run on Ethyl there is no audible detonation at any speed or throttle opening, even with the hand ignition control fully advanced. There is nothing unusual about the engine or body mounting, there does not appear to be contd :- | ||