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).
Weight analysis comparing the B.V. (mainly 9-B-V) and a 1939 Humber Super Snipe Saloon.
| Identifier | ExFiles\Box 126\2\ scan0177 | |
| Date | 3rd August 1939 | |
| 3.8.39. WEIGHT ANALYSES - B-V & HUMBER SUPER SNIPE. Attached is a list showing the relative weights of groups of parts of the B.V. (mainly 9-B-V) and a 1939 Super Snipe Saloon. In comparing these weights two main factors must be kept in mind - (a) The B-V is a larger car with 10" longer wheelbase, 2" wider track, has mechanical servo, brakes, centralised lubrication, a front suspension which relieves the springs of brake torque and wheel location and many special features. (b) Owing to differences in design and layout, it is often difficult to so arrange the groups of parts so as to provide a really fair and direct comparison. The fact remains that there is a difference of over 400 lbs between the two chassis, and with the exception of the Frames and Fittings section most of this is distributed amongst some 23 other sections, some of which should be re-considered and some of which unquestionably justify some small extra weight. The following is a general review with brief remarks on each section:- (1) The B.V. engine is 119 lbs. lighter, but only 12.5 lbs of this is accounted for by the hollow crankshaft, but the Humber Crankcase and cylinder block + head is 288 lbs. against 192 lbs. for the corresponding B.V. parts, inspite of the Humber Al. head. (The B.60 engine is slightly lighter still, mainly on account of the Al. head, and a belt drive replacing some timing gears. (2) The B.V. gearbox (less servo) is 12 lbs. lighter, mainly on account of the al. gearbox. (3) The B.V. rear axle is 12 1/4 lbs. lighter with brake parts and levers, but without brake drums. (4) The B.V. brake drums are each 8 lbs. (or 66%) heavier. (5) The rear springs of B.V. are 7 lbs. lighter, in spite of the car being heavier. | ||