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).
EAC 'V' series engine oil consumption, comparing different piston designs and oil supply to bearings.
| Identifier | Morton\M3.1\ img001 | |
| Date | 1st April 1925 | |
| R.R. 493A (50H) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. FAC. OVEROILING Expl. No. REF: HS{Lord Ernest Hives - Chair}4/LGL.4.25. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. EJ. c. to RG.{Mr Rowledge} E.{Mr Elliott - Chief Engineer} c. to DA.{Bernard Day - Chassis Design} EY. c. to Wor.{Arthur Wormald - General Works Manager} S E C R E T. EAC. 'V' SERIES - OIL CONSUMPTION. X8040 X.5950 We attach herewith charts which show comparative oil consumption figures. It will be seen that the latest pistons with a groove below each ring are an improvement over the original pistons. This confirms the previous tests with similar pistons with 4 rings. We have fitted a set of these pistons to the next car to start 10,000 miles. The curves show that the oil consumption per B.HP. hr. is quite good. We can say definitely now that there is no improvement in oil consumption when we supply oil to the three main bearings only, compared with when it is supplied to all seven bearings. We notice on the new piston castings with the boss for the slit to run into, that we get slight signs of seizing even in the split side near the vertical split, which is very unusual - the boss will have had the effect of reducing the flexibility of the skirt - it may demand slightly different clearances in the bore. Hs.{Lord Ernest Hives - Chair} | ||