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).
Comparison of Brinell hardness at various points on centrifugally cast and individually cast piston rings.
| Identifier | ExFiles\Box 132\4\ scan0109 | |
| Date | 19th October 1937 | |
| -17- FIG. XV CENTRIFUGALLY CAST RINGS LIGHT PRODUCTION Co. WELLWORTHY MTHS{Reg Matthews} 1.12.36 VARIATION IN BRINELL HARDNESS AT VARIOUS POINTS ON PISTON RING FIG. XVI INDIVIDUALLY CAST RINGS HEPWORTH & GRANDAGE SEALED POWER (AMERICAN) MTHS{Reg Matthews} 1.12.36 VARIATION IN BRINELL HARDNESS AT VARIOUS POINTS ON PISTON RING The adoption of the Hepworth and Grandage rings would save approximately 2/- per chassis on 25/30 H.P. and Bentley. With the proposed lowering of cylinder Brinell the single cast ring should be better than the centrifugally cast ring, if as other peoples experience of rings, slightly harder than cylinder is true. Referring back to Fig. VI it will be seen that once the oil is warmed up thoroughly the small hole in the connecting rod would not deliver much oil since with the reduced pressure the leakage past bearings would have a greater effect on amount of oil supplied by extra oil hole. Again a greater oil supply would possibly have an effect on bore wear, more particularly on cars used for town work where engine speeds are necessarily low. As will be seen from the curve the actual oil consumed with the pressure varying in the normal manner, is much less at the low speeds, which means that there is by no means the same | ||