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).
Engine capacity modifications and design considerations for the 'Bensport' model.
| Identifier | ExFiles\Box 3\4\ 04-page068 | |
| Date | 2nd July 1932 | |
| Y4553 To R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} E.2/HP.2.7.32. c. Sg.{Arthur F. Sidgreaves - MD} Mor. Hs.{Lord Ernest Hives - Chair} re Bensport. ------------ The reduced capacity of the Bensport with 3.875" stroke is 2220 cc., or 6% less than Peregrine. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} has, however, suggested that the bore might be increased from 2.725" to 2.76" so that the capacity would be 2290 cc. or only 3% less than Peregrine. This is then just under the limit of 2300 cc. for competing in the 3 litre class. It would increase the tax of the rating by one pound above that of Peregrine. With the present cylinder construction the liners are .125" thick, and the metal between the liners of neighbouring bores is at an irreduceable minimum. We should not like to make the liners any thinner, and we should, therefore, suggest if you consider the slightly increased bore worth while that the cylinder centres be increased by an approximately like amount - say .05". This would not affect anything, as there are no patterns in existence for the design we have now, nor are there any pieces affected as regards interchangeability with regard to Peregrine. Peregrine is going ahead with the stiffened up crankshaft of 4.125 stroke, which we instructed, and the improved form of head. E.{Mr Elliott - Chief Engineer} | ||