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).
Torsional rigidity and proposing a return to an all-welded construction for eight-cylinder frames.
| Identifier | ExFiles\Box 124\2\ scan0266 | |
| Date | 31th October 1940 | |
| 10444 C O P Y. To Rm.{William Robotham - Chief Engineer} EIGHT CYLINDER FRAMES. ------------- It is felt that eight cylinder frames will be liable to front end shake when fitted with drop head coupe or sedanca bodies. To overcome this, it will be necessary to increase the torsional rigidity between the dash and the front wheels. We consider that the best and simplest way of doing this will be to return to an all welded construction as used on 7-B-V.{VIENNA} There are three places where the welding is definitely needed, namely between the pan and the side members, between the cross and the side members, and between the gussets and the cross. Having gone so far it would be better to be consistent and throw away all the rivets and have a completely welded construction. The fact that an all welded frame cracked up on the bump should not be allowed to affect the issue because the bump was then being run at the critical speed of the frame, and it was bound to crack up fairly quickly. In addition, we were using 3" cams for bumping while no other manufacturers find it necessary to use more than 2" cams. On 7-B-V the torsional strength between the dash and the front wheels was 4600 lbs. ft./degree whilst the best recorded figure on any subsequent frame has been 3850. Our latest frame, when all welded, should give a higher figure than 7-B-V, and we might expect at least 5000 lbs.ft./degree. A cast aluminium dash would also give a noticeable improvement in overall rigidity and should be standardised for soft top motor cars. It would be very interesting experimentally to put 10-B-V's body on 7-B-V, both with a pressed steel and a cast aluminium dash to see if we could get away with it without the extra scuttle stiffening at present on 10-B-V.{VIENNA} Rm{William Robotham - Chief Engineer}/Clm.{D. D. Clapham} | ||