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).
Letter to The Light Production Co. Ltd. concerning the manufacturing process and specifications for lighter split skirt pistons.
| Identifier | ExFiles\Box 148\1\ scan0308 | |
| Date | 11th February 1941 | |
| 1256 EXPERIMENTAL DEPARTMENT. 11th February, 1941. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}3/RH.{R. Hollingworth} The Light Production Co., Ltd., 68, Liverpool Road, Trading Estate, SLOUGH. Attention of Mr. Brooke. Dear Sirs, Further to our correspondence concerning a lighter split skirt piston. Referring to the range of sizes sent to you on 22.4.40; the piston RR.785 was a copy of a previous piston we had used ED.{J. L. Edwards}1299. You will recall that we purposely concentrated upon these two drawings in producing a 3.250 bore piston weighing not more than 16 1/2 ozs. The last set of pistons supplied were faked by you during the foundry work, in order to produce the section thickness to drawing. The reason for this being due to the fact that a metal die, would produce slightly lighter sections all over. We are satisfied that this object was attained, and would now like you to go a stage further as follows. You have already produced foundry equipment to make RR.786, but the sections were increased in proportion to the increase in bore size from 3.250" to 3.500". We would like you to make 14 pistons as follows. To suit 3.500 bore, but with the same section thickness all over as RR.785. This to be done by faking the foundry work as before. In this way we should obtain a piston weighing no more than 16.25 ozs for a 3.500 bore. We would like you to finish these 14 pistons by machining to your own eccentric grinding. Yours faithfully, | ||