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 performance, detailing issues with plugs, timing, noise, and the clutch, with a comparison to a Mercedes engine.
Identifier | ExFiles\Box 25\3\ Scan056 | |
Date | 22th July 1914 guessed | |
Wor{Arthur Wormald - General Works Manager}/H18/L21714. Sheet. 2 Mercedes. X634 I like the idea of the two distributors on the magneto and two plugs, we had a little trouble with pre-ignitions, I believe it was due to the plugs, they were the new type Bosch; for racing and high compression engines the Bosch make a special plug but they could not be used on this engine because they would not work in the oil these plugs get at light loads. The valve timing is very similar to ours, the magneto is set to fire one minute late on the flywheel. The crankshaft periods are terrific on this car, the worst are at 1200 revs and 2300 revs; beside the actual periods the engine "thrashes" badly, it is very similar to the little 4 cylinder Mercedes in this respect. The compressions hold very well indeed, there can be very little leakage past the rings because so little smoke comes from the crankcase vents. I suggest lifting a pair of cylinders after the road tests. The engine is very noisy, it comes from the tappets and the camshaft drive. Except for the power the engine is a brute, the carburetter has a lot to do with it, it is so difficult to get the engine to pick up. We had some trouble with the clutch, it will not pick up anything like the full load, I do not | ||