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).
Road test report on a Peregrine engine, detailing the results of using modified scraper rings to improve mileage per gallon.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page259 | |
| Date | 5th April 1933 | |
| X4025a E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}1/KT.5.4.33. We have carried out a test on Peregrine using scraper rings following our aero engine practice by chamfering the perfect circle ring and tapering the bottom gas ring as per sketches. On the first road test we got no improvement presumably because the cylinders had done 10,000 miles, and would be, therefore, not quite round, and the rings took some time to bed in. Our second test, however, has shown that we have increased our m.p.g. by 50%. ROAD TEST FIGURES. Mileage 170.5 Average Speed 42.5 mph. Petrol used 11 galls. Petrol cons. 15.45 mpg. Oil used 3.3 pts. Cons. 413 mpg. Old type scraper rings to E.100037 Gas ring to E.100036 Mileage 182. Average Speed 42 mph. Petrol Used 11.5 galls. Petrol Cons. 15.84 mpg. Oil used 3.5 pts. Oil cons. 416 mpg. 1st test. New expl. scraper ring to Hs.{Lord Ernest Hives - Chair}945. .015 chamfer on the scraper ring, the groove being shallower to increase the unit pressure. Mileage 176. Average speed 42 mph. Oil used 2.25 pts. Oil cons. 625.6 mpg. 2nd test. " " ------------------ Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||