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 development of several radial engines, including Diesel and water-cooled types.
| Identifier | ExFiles\Box 178\2\ img070 | |
| Date | 7th March 1940 | |
| Serial No 8 Rm{William Robotham - Chief Engineer} page 3 OY 8/D/Mar 7.40 Radial Engines Ripingille said they were working on three sizes: 1. A radial type Diesel (I believe) with 6" cylinders, 100 H.P. per cylinder and 130 B.M.E.P. 2 cycle. 2. A 4-8 cylinder water-cooled radial, 2-cycle of 252 cu.in. and 175 H.P. at 2350 r.p.m., 117 B.M.E.P. Carbyretter engine with centrifugal blower. Weighs 260 lbs. without starter and generator. We saw this. 3. The old small version of this of 120 cu.in. All use the same type of slipper rod in various sizes. Several of the No 2 engine have already been built. One is running on propeller test stand at the proving ground, and several are now in cars and are at present touring the Southern states. (I presume these are rear engine cars - a larger development of Schjohn's design of 5 years ago, probably with hydramatic trans-mission. (They are not - the engine is in conventional forward position - OY Mar 8) In working out this general design of a radial engine which should be, with its balance weights, in complete balance, it was ob-viously essential to produce a con.rod without the angularity de-fects of the articulated rod. The design of the engine, therefore, started with the big end and with the original single-acting rod testing machine. As a result, Rip. considers they have shown that the slipper type rod is a sup-erior design for any engine. 4) We saw one of the 252 cu.in. engines dismantled for over-haul. The design is primarily for auxiliary work on large bombers or for motive power on light planes. Its use in cars may or may not be seriously intended, but if so, is three to five years ahead, I believe. The two-cycle valveless design with inverted U type twin cyl-inders has now been in development at G.M. for about five years, and Rip. said is the only type they are interested in. Cylinders are cast in pairs in aluminum with C.I. wet liners like the truck Diesel liners. Supercharger has aluminum alloy rotor cast in permanent mold and unfinished except on outside clearance faces. About 7" diameter running about 10 1/2 times engine speed. (A blower of some sort is essential to the design.) | ||