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).
Technical report on the advantages and testing of Aerolite pistons.
| Identifier | ExFiles\Box 86\2\ scan0188 | |
| Date | 30th April 1934 | |
| To Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c.c. to Nor. c.c. to E.{Mr Elliott - Chief Engineer} c.c. to Hy.{Tom Haldenby - Plant Engineer} c.c. to Dn. c.c. to Hn.{F. C. Honeyman - Retail orders} c.c. to EV.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}5/KW.30.4.34. AEROLITE PISTONS. Referring to Sg.{Arthur F. Sidgreaves - MD}1C/E.19.4.34. The advantages which these pistons have over our present standard split skirt type are - (a) Improve top horse power about 6% (Hs{Lord Ernest Hives - Chair}/Wths.1/KW13.2.34). (b) Increase in accelerating capacity of the car by about 5% over the speed range. Curve E.V.19 above report. (c) Reduction in heat to the cooling water of 430 B.T.U's per minute at top speeds or 12% of the total. This should permit a small reduction in radiator size. (d) An improvement in mechanical efficiency of about 7%. This should give us an improvement in petrol consumption at partial throttle openings and perhaps facilitate starting. Tests on these points are as yet incomplete. We have carried out sufficient test bench running to be able to say that at the present power output of 120 B.H.P. and maximum speed of 4500 R.P.M., these pistons are absolutely reliable mechanically. On the road we have covered in all about 42,000 miles, which include two 10,000 mile tests in England. We have formed the opinion that these pistons are not likely to be appreciably more susceptible to cold knocks than our present standard pistons. Further experience in France is necessary to confirm this. Wear on the ring grooves and skirts seems reasonable, and they maintain a consistent oil consumption. We think that we can improve the shape of the piston a little as a result of our experience. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||