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).
Production modifications for B.V. chassis to address faults in brake linkage, clutch, and suspension dampers.
| Identifier | ExFiles\Box 97\2\ scan0139 | |
| Date | 27th April 1940 | |
| JRD. from Rm{William Robotham - Chief Engineer}/FJH{Fred J. Hardy - Chief Dev. Engineer} Sg{Arthur F. Sidgreaves - MD}? HS{Lord Ernest Hives - Chair}} copies C Rd. PRODUCTION MODIFICATIONS. B.V. We have now obtained further running experience on B.V. since it was originally instructed for production, and we recommend that the following modifications should be incorporated in the chassis you are completing in order to overcome faults which have come to light. 1- Brake Linkage binds up due to inadequate clearances and rusting of pins. The brake linkage should be modified as specified on the attached Rm.{William Robotham - Chief Engineer}611. 2- Clutch thrust bearing receives inadequate lubrication due to bijur oil being blown away from trough by flywheel draught when bijur pipe is not accurately placed over trough. The pipe should be placed within limits shown on the attached print Rm{William Robotham - Chief Engineer} 620. 3- Troubles which have become apparent on front suspension dampers:- (a) Leak holes in rivets holding replenishing valves to valve springs are liable to become blocked by dirt. These holes should be omitted and replaced by grooves across the seats of the replenishing valves as shown on the attached FB.5262/3. (b) Main valve chatter is liable to occur resulting in grunts and squawks from the dampers. The cure is to replace FB.4279 by RF.956, as per attached print. (c) End play in the main damper shaft in excess of 0.002 causes knocks from the front suspension. This end play should be reduced to 0.0005 - 0.0015 by copper plating the end faces of the internal rocker lever or, if the clearance exceeds 0.010, inserting soft steel washers. (d) Sr. has found the following faults on the front dampers of his chassis B.12.AW: Excessive quantities of dirt inside the dampers. Main cylinder bores taper by 0.003. This is exceptionally bad. Cap, FB.4251, on main valve stem FB.4250 able to turn round so that holes in cap do not register with holes in valve stem. Cap FB.4251 touching valve guide FB.4248 before valve has reached its seat. There should be 0.005 clearance between the cap and guide when the valve is seated. All the points above should be checked on production dampers. | ||