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).
Comparative analysis of competitor gearboxes, suspension systems, and engine arrangements.
| Identifier | ExFiles\Box 173\4\ img215 | |
| Date | 5th November 1935 guessed | |
| (sheet 5) did not appear to be as quiet as Rolls-Royce. Most that I heard were very much more noisy. Packards were the only example of a quiet box. We found no separately mounted gearboxes. We have brought home drawings of the Packard gears box, which has some interesting points, and some particulars of other gearboxes. Lincoln boxes which seemed remarkably good in the silence chamber, were definitely noisy on the car. (5) We have reported that Dubonnet suspension is regarded as inferior in almost every respect to wishbone arrangement. (6) Engine Arrangement. It is generally agreed that the Vee 12 makes a very smooth engine, but the Zephyr showed that it is possible to make it very rough. It appears to be possible to eliminate or much reduce the torsional periods by a harmonic damper of reasonable size. There are no lateral vibrations. On the other hand the Vee 8 can be made very smooth by a special flywheel. As it is certainly simpler, cheaper and more compact, it may be thought to be more practical for the smaller cars. It is believed, however, that it will be necessary to use a side valve engine to get it into the bonnet, and as the volumetric efficiency of this is less than an overhead valve engine at high speeds, this may be a serious objection. Cadillacs prefer the Vee 8 to the Straight 8 on account of its compactness, but the Straight 8 is thought more easy to make smooth. It may be interesting that Fords are designing, through Mr Tjaarda, who does a good deal of their advanced design work an aluminium block engine (Vee 8) with wet liners (nitrided steel) inserted valve seats and plug holes etc. very much on the lines of Phantom 3. The reason for this is that they are aware that their engines weigh relatively too much. He says their engines now weigh from 5 to 10 lbs per HP and they are expecting to bring it down to 3 lbs per HP, with an aluminium engine. I was to have seen this engine, but it was crowded out by other things. They are trying to make the sparking plugs themselves of bronze. | ||