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).
Comparison of flywheel and clutch plate weights and specifications between R.R. and Napier models.
| Identifier | ExFiles\Box 23\2\ Scan015 | |
| Date | 10th October 1912 guessed | |
| X437 the flywheel which made all the noise(same as we found in the R.R clutch) If we increased the weights of these plates the jingling was very much worse. Comparative weights of plates. R.R.original, thin asbestos. .875 lbs. R.R.larger diameter, thick asbestos 2.000 " Napier. .201 " Napier made heavy to jingle. .812 " The Napier has the same number of keyways as R.R. ie 12, ie hub and flywheel portion. No. of plates Napier 53. R.R. 14. Movement of Clutch, Napier. .187" | ||