Modifications and investigations for the Bensport Chassis, focusing on air silencers, crankshaft bearings, and radiators.
| Identifier | ExFiles\Box 30\2\ Scan226 | |
| Date | 23th May 1933 | |
| E.1/HP.23.5.33. ---------------- re Bensport(Codename for 3 1/2-litre Bentley) Chassis. ------------------ Air Silencer. The 15 sets ordered of the 20-HP. should be stopped, as a fresh design is being instructed with F.2. size of silencer, in conjunction with the larger air inlet elbow, as shown on LeC.3500. The angle of the elbow requires correcting for the accommodation of the larger diameter silencer. Crankshaft and Bearings. The present Bensport(Codename for 3 1/2-litre Bentley) engines are equipped with the Phantom 2 system of side grooves in all bearings with single oil holes through all crankshaft journals. The present engines are suffering from three faults - No.1. A larger quantity of oil appears to be escaping from the bearings than on Bensport(Codename for 3 1/2-litre Bentley) No.1. No.2. There is a considerable leak at the rear crankshaft bearing. No.3. There is a mysterious fall of oil pressure after a speed burst, and it takes some time before the pressure builds up again. Items 2 and 3 cannot be attributed to the grooving of the bearings, and their cause is being investigated. The engine in No.1. Bensport(Codename for 3 1/2-litre Bentley) follows the 20/25 practice of circular grooves in Nos.1, 4 and 7 bearings, no grooves in intermediate, and single oil holes in all journals. This engine is satisfactory in all respects, and as it is necessary to instruct something immediately of which we are sure, the drawings should be altered to show the 20/25 system. The other system is not satisfactory, either on F.2. J.3. or Peregrine(Experimental Bentley car never produced / Aero Engine), and we are anxious not to increase the amount of oil being flung about in the engine as this may necessitate fitting an oil cooler. One engine should be instructed with the side grooves in the bearings, however, in conjunction with three holes in the crankshaft journals, for experimental test, with lead bronze bearings as the lead bronze big-ends are not showing up satisfactorily on the Bensport(Codename for 3 1/2-litre Bentley) engine with the F.2. type of lubrication system. Radiators. The design for the Swallow(Experimental 3rd LINE MODEL 12/15hp 2-3 seater) type of grille should | ||
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).