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).
Engine development, covering petrol injection, cylinder temperatures, operating issues, magnesium use, and oil cooling.
| Identifier | ExFiles\Box 173\1\ img171 | |
| Date | 2nd February 1934 | |
| -2- IM/KL.3/KM.2, 2.2.34 Petrol Injection. This is not yet in production. One engine is still running on the commercial routes, three others elsewhere, and the general impression seems to be that it is very satisfactory. Its main virtue is that under no condition can it "ice up" - the bugbear of commercial flying in winter here. On an ordinary engine they raise the mixture temp. by as much as 100°F.{Mr Friese} by exhaust heaters, and yet if the pilot forgets to switch the heat over to max. before he begins to ice up he cannot clear the trouble and will have to forced land. Leading edge trouble similar (steam cooled ado). Cyl. Temps. Asked them what max. cyl. temps. they record on climb in the air. They say 500°F.{Mr Friese} exhaust valve seat 400°F.{Mr Friese} rear spark plug 92 M.P.H. air speed, weakest mtl. If they go up full strong rear spark plug temp. drops 80°F.{Mr Friese} Under race conditions, piston temps. run at about 350°F.{Mr Friese} under the ring belt with their latest ribbed cooled crown. Troubles. These seemed to be confined to sticking rings, oil consumption maintenance at a constant figure, as it varies with the ring and cyl. bore finish and cylinder wear. No bearing troubles, valves O.K. at present output. Magnesium. Use being steadily increased. Not yet used for the crankcase proper except in special racing engines, but used for the gear case on latest geared engines. Oil Cooling. No oil coolers required below 135 M.P.H. They have not yet established high oil temps. as being harmless but are thinking that way. They hold inlets to bearings at 180°F.{Mr Friese} at present. There seems to be a tendency on the part of the army and Navy to tighten up restrictions re people seeing experimental engines. No Japanese are allowed into any military or naval controlled factory. I have heard about the 1000 H.P. Allison Ethylene Glycol cooled engine but so far have no particulars. | ||