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).
Road performance review of a car, followed by detailed specifications for a Hispano Suiza 12 cylinder engine.
| Identifier | Morton\M19\ img260 | |
| Date | 26th October 1931 | |
| -3- between 3000 - 4000 r.p.m. the engine was really delightfully smooth and there was no vibration on the over-run. The cylinder block is a solid casting with the top half of the crankcase. Road Performance. This car has a very good performance for an engine with a 2 1/4 litres capacity. They do not get a good pick up below 25 m.p.h. on top gear, but this is not noticeable as they have a good silent 3rd. At cruising speeds from 50 - 60 m.p.h. the engine is full of life. The engine behaves in a very refined manner (except for the exhaust) considering the car's reasonable price and excellent performance. The brakes were not particularly good and the suspension was definitely very bad, but we understood that M.G's have not made any special effort with suspension but cater for the driver who wishes to proceed as fast as possible all the time. We should say from the detonations that these people have recently again raised their compression ratio and we have no knowledge of what effect this might have on the durability of the car. We do know, however, of one of these cars that has had a lot of hard driving during the past two years, during which it has not suffered any mechanical failure. We should estimate that the top speed of this car with the saloon body would be somewhere about 75 m.p.h. Perhaps the most interesting point about these two power units was that they neither of them appeared to suffer from over-run vibrations which we have found so troublesome on the 25 HP. and to suppress which we have had to evolve the diamond engine mounting. HISPANO SUIZA. 12 CYL. 100 x 100 mm. 60° 9424 cc. Dual ignition. 2 plugs/cyl. Alum. block. Seven bearing crankshaft. Nitrosiloy liners, screwed in at the top. Adjustable rubber gland at the bottom. Side by side connecting rods. Engine mounted on three points, silent block bushes, the single point at the front. Silent 2nd speed (3 speed box) giving 3000 R.P.M. at 60 M.P.H. Axle ratio 15/51. Springs have silent block bushes and no lubrication points. | ||