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).
Phantom II high-speed engine vibration experiments, investigating the effects of replacing the crankshaft and removing clutch components.
| Identifier | ExFiles\Box 14\2\ Scan052 | |
| Date | 8th November 1929 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Ten. c. Sg.{Arthur F. Sidgreaves - MD} c. WOr.{Arthur Wormald - General Works Manager} Da.{Bernard Day - Chassis Design} c. E.{Mr Elliott - Chief Engineer} Ry. *7010 Not sent out Hs{Lord Ernest Hives - Chair}/Ten5/AD8.11.29. x634. x7010 PHANTOM II HIGH SPEED ENGINE VIBRATION EXPERIMENTS. ------------------------------------------------- These tests have been continued under the same conditions as before, namely with the rear wheels driven by drums, a closed body was fitted (axle test rig) and the engine feet were standard Phantom II sandwich type. The speedometer, unfortunately had to be changed since last test as it was found to be packing up. Some of the things we have discovered will probably upset preconceived ideas very considerably. (1) Plain parallel shaft replacing crankshaft. ---------------------------------------- The flywheel was fitted one end and standard type spring drive the other, as usual. Body booms occurred at 26 and 31 m.p.h. in 2nd gear. Engine vibration and noise was considerable over 40 m.p.h. (3000 R.P.M.). Vibration could be detected at the gear box. Theshaft and flywheel were removed, and found to be 1/2 oz. out of balance at the rim. This was rectified and re-run but no improvement was detectable. (2) Clutch parts of flywheel removed. ---------------------------------- Sole part left was flywheel plate bolted on crankshaft. A ring was made to bolt on instead of the clutch plate and drive to the flywheel bolts direct. The engine was then very much smoother up to | ||