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).
Conference notes on the design and modification of a supercharged Bensport engine, including details on supercharger position, crankshaft and back axle.
| Identifier | ExFiles\Box 178\3\ img289 | |
| Date | 22th July 1932 | |
| SG.{Arthur F. Sidgreaves - MD} FROM R.{Sir Henry Royce} C. to MS. EX-Evernden. BENSPORT ENGINE. R2/M22.7.32. X4553 CONFERENCE AT WW. THURSDAY, JULY 21. PRESENT SG.{Arthur F. Sidgreaves - MD} R.{Sir Henry Royce} WOR.{Arthur Wormald - General Works Manager} MS. E.{Mr Elliott - Chief Engineer} It was decided that we should at once try a Peregrine engine with a blower at the front, and that we could make up temporarily a workable mock up of a Bensport engine with this arrangement, and in connection with this I suggested that the radiator frame and shutters could be of the Bentley appearance, but the cooling matrix for the water should be straight across, and more or less over the top of the supercharger, so that we should be gaining considerably in length, and not making a sham but a reasonable arrangement of the shutters working, and the face of the shutters forming a controlled front for the radiator and supercharger. The supercharger would still have to be of the short type and we hope that this arrangement, and perhaps bringing the shutters forward a little, will still enable us to bring the engine 1/2" forward of the position formerly demanded by the blower in the front. This should make an enormous improvement in the vicinity of the dash and foot pedals. This W. is investigating. Owing to the result of recent experiments it is thought that the forward position of the supercharger gives definite advantages to outweigh the possible disadvantages of slow running and snap acceleration. We have therefore, definitely decided to abandon the side position of supercharger, and the complication in the engine, etc, that this brought about. We hope to get out a drawing of the engine with its supercharger at a very early date, and we understand the supercharger is to be coupled to the engine by the RR. disc Bibby type coupling. A universal spring drive somewhat damped can run satisfactorily in oil. It will be noted that the crankshaft of Peregrine and Bensport being reduced to 4" stroke will just enable it to meet the 3 litre class which we think is necessary for this little sports car to have some chance of competing with other 3-litre engines. It was estimated that the back axle having 25% more teeth in the pinion will enable it to better meet the increased torque developed by the supercharged engine. The two back axles will be brought in line as far as possible for manufacture, but it should be noted that the Peregrine chassis must last many years at moderately high speeds, and that the Bentley sports will have to be thoroughly reliable, but need not have the same wearing qualities as the Peregrine. R.{Sir Henry Royce} | ||