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).
Analysis of engine smoothness, crankshaft periods, and a comparison of flywheel and clutch inertia.
| Identifier | ExFiles\Box 125\2\ scan0054 | |
| Date | 14th June 1929 guessed | |
| contd :- -9- since when we removed it we could hardly detect the crankshaft periods, which were a great contrast to the ones on our own engines with no slipper wheels. We do not know definitely why this engine should be so smooth with no damper, but would suggest the following as contributary factors : (1) Fairly stiff crankshaft. (2) Very stiff crankcase. (3) New engine i.e., it might become worse with use as the Stutz did. (4) Front end drive by silent chain. Some firms (e.g. 20-60 Vauxhall and Morris 6-cyl.) claim that with this type of drive no crankshaft damper is required. The only low speed period we could detect with certainty was at 23 m.p.h. in 2nd. gear - the top period is at approx. 45 in 2nd. The hub of the slipper wheels is combined with the fan pulley, it is simply forced on to the parallel nose of the shaft, with a key and retaining nut. It is a heavy piece, and we believe would soon shake off if similarly attached to one of our engines. FLYWHEEL & CLUTCH. The moment of inertia of this is very low compared with our own, as follows : 20 HP. standard .691 slugs.ft2 ( M k2 / g ) Chrysler .360 " " Std. Phantom 1.384 " before lightening contd :- | ||