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).
The advantages and test results of Aerolite pistons.
| Identifier | ExFiles\Box 86\2\ scan0186 | |
| Date | 28th April 1934 | |
| NOT SENT OUT To Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Bn.{W.O. Bentley / Mr Barrington} c. to Ev.{Ivan Evernden - coachwork} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}5/KW.28.4.34. AEROLITE PISTONS. Referring to Sg.{Arthur F. Sidgreaves - MD}10/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}/Mths.{Reg Matthews}1/KW13.2.34 (b) Increase in accelerating capacity of the car by about 6% over the speed range. Curve B.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 running under normal conditions we have two sets, one in R.R.53 alloy and one in the 10% copper alloy that have done about 9000 miles each and are free from cold knocks. We have a further set of pistons, five of which ran 19 hours on the test bed under full throttle high speed endurance tests and then did 23,000 miles on the road under 10,000 mile test conditions, oil consumption remaining at 1,000 M.P.G. throughout. Two of these pistons have developed a cold knock. The sixth piston, which did the 23,000 miles road running only, was perfectly silent. | ||