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).
Saginaw vs. Gemmer steering gears and a performance analysis of a Lincoln Zephyr 12.
| Identifier | ExFiles\Box 173\4\ img154 | |
| Date | 30th November 1935 guessed | |
| -3- As between the two I should say it would be wiser to follow Saginaw rather than Gemmer at the moment. Saginaw impress one rather more, and their gears seem more irreversible. I wonder however whether it would be wise to buy a Gemmer gear for adapting to the chassis for trial. They have a great many forms of boxes, and one suitable could I think be found. -------- Lincoln Zephyr 12. We tried a Zephyr round the Lincoln Track. As the track was covered with ice and snow, it was not possible to exceed 40 m.p.h. and much slower at bends. There is no doubt about the roughness of the engine, though Grylls thought it rather less rough than the one he tried first. It is difficult to be dogmatic about the cause of roughness, but it is suggested that it may be because:- (1) It is made in a Ford Factory by Ford methods. No bedding or reducing of the crankshaft bearings at all is done. There appeared to be a lot of crankshaft bearing clearances. The pistons, of semi-steel, are fitted with a .002 clearance by a very rapid method. (2) The crankshaft is C.I. which would have, one supposes, a low modulus of elasticity. (3) There are lead bronze strip bearings apparently with large clearances. (4) The angle of the 'V' is 75°. (5) There is a small flywheel. (6) There is a very small, dry, friction damper right out on the front end of the crankshaft, which looks very unlikely to be adequate. The engine ran through two torsional periods in accelerating. The acceleration from dead slow seemed very poor, inferior to that of the large (and very heavy) Lincoln 12. The gears were noisy, the transmission chunked badly, the rear axle was terribly noisy, and so was the exhaust. The riding, however, was good, especially in the rear seats, and the car seemed handleable, though of course we could not go fast. | ||