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).
The condition of a crankcase, crankshaft, spring drive, and connecting rods after running tests.
| Identifier | ExFiles\Box 83\2\ scan0057 | |
| Date | 31th May 1937 guessed | |
| ( 2 ) CRANKCASE & BEARINGS. LOP. EB.2737. New, complete to the above LOP. incorporating:- Hoyt's Z.3. Main Bearings with normal W/Mt. clearances. Liners in RR.56. The grooves in the bearings carried right round. The main bearings were found to be in very poor condition when stripped. They had not prevented maximum speed and performance being used, but were responsible for roughness and engine periods being noticeable. CRANKSHAFT. LOP. EB.2700. Complete to above LOP. incorporating:- E.61223 Crankshaft V.CM. Extra hole drilled in each crank journal opposite existing. SPRING DRIVE. LOP. EB.2666 LEC.4629-4946. Complete to above LOP & Schemes Ex.B.22 unit incorporating:- Rm.{William Robotham - Chief Engineer}252 mod. to dampers i.e. lightened Damper Wheels. Damper Load re-set at 18.1/2 lbs. at 17.1/2 Rad. No trouble was experienced with the spring drive, although when stripped, it was reported that an excessive amount of sludge was present owing to there being no drain holes. The crankshaft vibrations were damped out until the slack in the main bearings became excessive. CONNECTING RODS. LOP. EB.2704. Existing complete to the above LOP. incorporating:- The following new parts:- Big-end Bearings in RR.56. Liners in RR.56. Clearance .0024" Removed after 2.500 miles running and replaced by six new connecting rods. Nos. 1, 2, & 3, Big-end Bearings in A.C.5.S. Nos. 4, 5, & 6, Big-end Bearings in A.C.6.S. No 6 big-end bearing in RR.56 seized on the crank-pin after 1.000 miles running. A new rod was fitted and running continued. All six bearings were in good condition when removed. The big-end bearings in A.C.5.S. and A.C.6.S. covered 12.500 miles and were all in excellent condition at the end of the mileage. | ||