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).
Experiments conducted on the Phantom II engine mounting to manage engine torque.
| Identifier | Morton\M19\ img187 | |
| Date | 2nd June 1931 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/les.{Ivan A. Leslie} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to Hy.{Tom Haldenby - Plant Engineer} Ha/Les.3/MJ.2.6.31. X.7005. X.634. PHANTOM 2 ENGINE MOUNTING. Acting on your suggestion, we carried out experiments using the torque arm at the rear of the gearbox to take the engine torque. The car we used for this experiment was 24-KX, which, when fitted with four the standard four sandwich feet, was a bad example of booming. With the Diamond engine mounting this car is free from booms. It is the yellow car which you tried at West WitteringHenry Royce's home town. The torque arm we used was made to W.Sch.2792. TEST (1). The torque arm was bolted solid to the frame. Under these conditions vibrations could be felt in the body when accelerating from 18 to 30 m.p.h. This was actually worse than the standard four sandwich feet. There was also a vibration on retard from 49 to 40 m.p.h. which was not there with sandwich feet. The booms in the body were much less than standard sandwich feet, but not as good as Diamond engine mounting without the rear torque arm. TEST (2). Diabolo engine feet rubbers were used between the torque arm and the frame. This made a slight improvement but the car was still definitely worse than without the torque arm. We tried with various loads on the rubbers. We also tried with the sandwich rubber 3/16" thick, this gave about the same results as the Diabolo rubber. SUMMARY. As a result of our tests we can find no advantage from the torque arm at the rear and we prefer taking the torque at the front end of the engine. We have tested the torque arm with friction dampers to see whether we could find any advantage from it in reducing torque reaction of the engine or frame jellying. We have not been able to find any advantage to be gained from it. The general scheme which we have received from W.W. for conversion of P.2 appears to give us all we require for a satisfactory engine mounting. Hs{Lord Ernest Hives - Chair}/A.J.Leslie. | ||