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).
Oil flow test results and subsequent engine analysis for chassis B.70.JD.
| Identifier | ExFiles\Box 114\3\ scan0023 | |
| Date | 20th January 1939 | |
| To By... from Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}4/N.20.1.39. Re: Chassis B.70.JD.{J. Draper - Frames} Car brought up to Derby for oil flow test. The oil flow figures taken were as follows:- 1st. at K.{Mr Kilner} 2 min. 50 sec. } 2nd. at D.{John DeLooze - Company Secretary} 2 " 15 " } at 48°C. crankcase temp. 3rd. at K.{Mr Kilner} 2 " 18 " } This verified that the soaking heat was not the same on the 1st. test as the two later tests. The oil pressures on the run down after a hard run were 15 lbs. at 90 M.P.H. idling 2 to 3 lbs. On this alone we should strip the engine. The large oil pump would not have given us more than 25% increase. The result upon dismantling the engine has proved once more that the oil flow test is a sure means of giving the condition of the bearing clearance irrespective whether due to bearing wear, crankshaft wear, or connecting rods. In this case the low oil pressure is due to chiefly crankshaft journal wear, actual wear of the bearings is practically nil, but slackness in the housing is of a fair amount. I am enclosing the actual figures of sinkage of main bearings. These do not include bearing dia. clearance. A chart of the crankshaft measurements is also enclosed. The item smallest dia. is measured on the top of the ridges, the bottom of the ridges is probably an increase of .0005". As a matter of interest I am sending you the crankshaft and main journal bearings for your inspection, and in view of what we discussed last week, this is a case of a reconditioned crankshaft being fitted in place of the one taken out. Finally the crankshaft required Mod.C. i.e. drilling. This has been done as you will notice. We should be obliged if, after your examination, the crankshaft could be reground and re-hardened and returned to K.{Mr Kilner} for stock. Cont'd.{John DeLooze - Company Secretary} | ||