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).
Bentley oil consumption tests showing results of different piston ring configurations and low viscosity oils.
| Identifier | ExFiles\Box 132\4\ scan0103 | |
| Date | 19th October 1937 | |
| -11- Fig. VIII shows farther results of tests with low viscosity oils, curve (1) represents the then standard arrangement of rings and curve (2) shows the effect of fitting an "L" section ring in the 2nd. compression ring groove. Curve (3) shows the effect of inverting this ring and the marked effect it has on the consumption. Curve (4) shows results obtained with rings supplied by Wellworthy's and which represented their ideal combination of ring and groove arrangements. The Simplex ring as on 25/30 piston gave very poor results, and the result is shown curve (5). Curve (6) shows the result of rings to American proportions supplied by the 'Sealed Power' Ring Co. of America, these were the type of rings we used for our road test. Fig. IX shows the oil consumption figures obtained with cylinder blocks machined in different manner, Curve (1) shows the result [Blueprint Chart Text] FIG VIII BENTLEY OIL CONSUMPTION TESTS AEROLITE PISTONS. CASTROL 'Z' OIL PRESS = 38 LB/□" R.P.M - 4000 OIL VISCOSITY :- 48.5 SECS. REDWOOD No 1. SCALE AT 100°c Y-Axis: OIL CONSUMPTION (PTS/HR) X-Axis: HRS. RUN CURVE ① 'O' TYPE PISTONS E.60820 COMP. RINGS E.60821 SCRAPER RINGS ② AS ① BUT WITH "L" SECTION 2ND COMP. RING ③ AS ② BUT WITH "L" SECTION RING INVERTED ④ RINGS AS SUPPLIED BY WELLWORTHY'S ⑤ AS ④ BUT WITH SIMPLEX RING AS 2ND COMP. RING ⑥ 'M' TYPE PISTONS. AMERICAN 'SEALED POWER' RINGS. COMP. RINGS. (BEVELLED) = 29.7 LB/□" SCRAPER RINGS. = 46.8 LB/□" MTHS{Reg Matthews} 7.1.37 | ||