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).
Modification to the F.10 engine specification, increasing the stroke, capacity, and power output.
| Identifier | WestWitteringFiles\N\October1925-December1925\ Scan78 | |
| Date | 7th November 1925 | |
| TO BJ. FROM R.{Sir Henry Royce} C. to - ~~CJ~~ HS.{Lord Ernest Hives - Chair} ORIGINAL R2/M7.11.25. MODIFICATION TO THE SPECIFICATION FOR RR. F.10. X.3804 / X5366 Owing to the recent information of the increased size of the Curtiss engine ( i.e. greater capacity by the increased cyl. bore) we have arranged that our F.10. engine, which was already 5" bore, shall have ½" added to the stroke. We have schemed to get this in the same dimensions that we have already sent you so that it does not alter the installation drawing, or the instructions to the 'plane builder, but increases the power at the same speeds, i.e. - @ 2000 RPM. 430HP. Commercial speed. ) Without @ 2500 RPM. 510HP. Fighting and racing.) supercharger. The dimensions, weight, and head resistance, are the same as shewn on LeC. 2133. The new capacity is 1300 cubic inches, and stroke 5.5". R.{Sir Henry Royce} [Illegible 'RECEIVED' stamp in bottom left corner] | ||