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 discussion on Tocco hardening, spark plugs, safety fuel, and engine varnish.
| Identifier | ExFiles\Box 178\2\ img045 | |
| Date | 30th March 1940 | |
| Rm.{William Robotham - Chief Engineer} - page 4 Serial No. 60 CY 1/D/Mar.30.40 appear? Would like to see your article. Shall have no difficulty in "selling" it to any one of a number of publications. Will write John Warner about putting it in the Journal. (g) Tocco Hardening For highly stressed cranks, Tocco hardening is not recommend- ed.{J. L. Edwards} See notes on Blanchard's conversation ( Cy 1/D/Mar.30.40, Serial No. 59). Much depends also on getting suitable steel for the job. (See my notes on Wyman-Gordon car crankshaft quotation.) Grain-size, cleanliness, etc., have to be above suspicion, finish of bell-mouth on oil holes must be good, etc. Where did the Leyland cranks break, and what were they made of? Magnaflux goes with Tocco hardening like night with day. Blackstone will have told you of our talk with Curtiss-Wright on Magnaflux. I have since had a brief talk with deForrest about it. England seems full of fake Magnaflux machines actually using the name, which is believed to be copyrighted, and not doing the job effectively. Accept only the genuine deForrest Magnaflux for adequate results (advt.) With the genuine machine nitrided cranks can be in- spected just as well as any other type. Rm.{William Robotham - Chief Engineer} 16, Halu 11.3.40 (a) Spark Plugs You will have gathered (from Cy 6/D/Mar.21.40, Serial No. 32) that Heron finds English plugs extravagant and founded on wrong principles in using thin platinum electrodes. But superior in the insulator to anything except the Battelle material. (b) Safety Fuel Since hearing what has been accomplished already, I am getting very enthusiastic about safety fuel. It appears to offer - Greater safety from fire than diesel fuel. At least equal volumetric efficiency to gasoline. Escape from carburettor icing. I think my suggestion of injecting 60% of the charge on intake stroke and 40% as a firing charge at end of compression stroke is not so dumb. All it would need if diesel fuel were used if a double-jerk cam. Ought to give diesel virtues in cold-starting and lack of radio interference with ability to burn all the air. Might use the Lanova head, of which I have sent particulars by Black- stone. (c) Varnish As I understand it, varnish and sludge formation is a function of engine temperature. See the copies of the S.A.E. | ||