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).
Standardising lubrication holes in the crankpins to prevent big end bearing seizure.
| Identifier | ExFiles\Box 115\3\ scan0037 | |
| Date | 28th June 1937 | |
| RR 755B (10H) 26074 2-11-36 WHK 24999 COMPLETED 23.8.37. BENTLEY STANDARDISATION of PARTS. Date 28.6.37. Description of Parts: LUBRICATION HOLES IN THE CRANKPINS. X No. 1020. Drawing No. Ex.27855. Origin: Siezure of big end bearings. Report of Experimental Test. In order to reproduce big end siezure on the test bed a 1/4 load maximum R.P.M. test was evolved. Under these conditions with standard bearings and lubrication, bearings failed after periods ranging from 5 mins. to 3 hrs. By having 2 - .125 dia. holes in each crankpin in place of single .2187 dia. hole we have since not had a single failure. Our latest run on the test bed has been 25 hrs. full throttle and 20 hrs. 1/4 load at the end of which the big ends in excellent condition. Oil consumption has been checked and does not appear to be worse. MATERIAL £ s. d.{John DeLooze - Company Secretary} | LABOUR £ s. d.{John DeLooze - Company Secretary} | CHARGES £ s. d.{John DeLooze - Company Secretary} | TOTAL £ s. d.{John DeLooze - Company Secretary} Cost of Old Part: 5 5 0 | 1 17 4 | 3 5 4 | 10 7 8 Cost of New Part: 5 5 0 | 1 17 7 | 3 5 9 | 10 8 4 Nett Increase: - - 8 Signature from Cost Dept. that above is correct. G/Rh{R. Hollingworth} 29.7.37. INITIAL | DATE | REMARKS SG.{Arthur F. Sidgreaves - MD} | 20-8-37 | Agreed SG.{Arthur F. Sidgreaves - MD} HS.{Lord Ernest Hives - Chair} | | Agreed Hs.{Lord Ernest Hives - Chair} C. | 6.8.37. | Agreed C. DA.{Bernard Day - Chassis Design} | 12.8.37. | Agreed Da.{Bernard Day - Chassis Design} BY.{R.W. Bailey - Chief Engineer} | 3.8.37. | Agreed By.{R.W. Bailey - Chief Engineer} RHC.{R. H. Coverley - Production Engineer} | 4.8.37. | Agreed RHC.{R. H. Coverley - Production Engineer} MX.{John H Maddocks - Chief Proving Officer} | 4.8.37. | Agreed Mx.{John H Maddocks - Chief Proving Officer} RM.{William Robotham - Chief Engineer} | 3.8.37. | Agreed Rm.{William Robotham - Chief Engineer} | ||