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).
Dynamometer and road test of a Phantom II Synchromesh gearbox.
| Identifier | ExFiles\Box 15\5\ Scan255 | |
| Date | 17th March 1932 | |
| 87310 R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c. to SE. c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to My. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}1/MA.17. 3. 32. P.II SYNCHOMESH. We have just completed a successful dynamometer test on this gear box. The car was run on each forward gear for half an hour at 2000 R.P.M. Top 3rd. and 2nd. gears were run full throttle giving a road wheel BHP of 106. We started to run 1st gear full throttle but with the low rating springs on the car and the consequent wind up of the axle and angle of the mechanics joint under a torque of about 4000 lbs ft., after 5 minutes the rear universal ran very hot lost a considerably quantity of oil by burning and became very out of truth. We therefore finished the test at 2/3 full torque. Reverse gear was run for 15 minutes 2000 R.P.M. 2/3 throttle. It should be added that the engine had the high lift camshaft, twin carburettors and 5½ C/R head. No trouble of any kind was experienced with the gear box, nor were there any oil leaks although the oil temperature reached 112ºC. On the road 3rd gear is very quiet but the change from top to 3rd is not as good as on the 25HP. The gear lever has to be moved slowly for a good change. We are therefore trying a smaller cone angle (6º instead of 10º) and also a lesser cam angle so that it shall be easier to move the sliding piece once the speeds have synchronised. Hs{Lord Ernest Hives - Chair}/H.{Arthur M. Hanbury - Head Complaints} Grylls. | ||