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 test report analysing engine performance, vibration, and noise characteristics on the road.
| Identifier | ExFiles\Box 127\2\ scan0007 | |
| Date | 27th August 1929 guessed | |
| -3- as 90 lbs/sq.in., which means a compression ratio of 4.5 from our test bed results. The maximum HP. is given as 90 at 2,800 r.p.m. so that the engine performance is very similar to the 40/50. The latest engines have a rubber engine mounting, the car we tried was not so fitted and so gave us a good chance of detecting periods. On the road we noticed the following points about the engine behaviour. Torque reaction. Almost non-existent. Pick up vibration. Appreciably worse than a good 6 cylinder engine, especially between 40 - 50 m.p.h. where there was a definate roughness. At maximum speeds on 2nd gear the engine got progressively rougher on forward but never approached the feeling of a 6 cylinder engine on the fringe of its master period. The engine must have run up to about 3,500 r.p.m. in this test, it was quite free, having covered 15,000 miles. On the over run the engine appeared to have the same characteristic as the La{L. A. Archer} Salle and Cadillac, that is it was commendably free from vibration. Engine noise was very similar to the other two cars there being a pronounced roar at all speeds above 25 m.p.h. which appeared to be a combination of valve timing, exhaust and carburetter suction. The position of the exhaust pipes makes one suspect that they are responsible for the major part of the roar. The body did not boom, even with all the windows up. SUMMARISING THE RESULTS:- None of the three V engined cars we tried are as | ||