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Over-oiling tests, gearbox noise, and clutch performance.


Identifier  WestWitteringFiles\N\2October1925-December1925\  Scan312
Date  31th December 1925
  
R.R. 493A (50 H) (D.D. 81, 12-6-25) J.H.D.

EXPERIMENTAL REPORT. -2- Expl. No. REF Hs {Lord Ernest Hives - Chair} /HS {Lord Ernest Hives - Chair} /LG31.12.25

'tinny' in proximity to manifold.
Detonations scarcely audible at any speed or throttle opening.

OVER-OILING.
We carried out careful tests to ascertain if this engine shewed any signs of oiling up plugs. The engine was run light for ten minutes and then suddenly accelerated; the quantity of smoke expelled from the exhaust was no worse than that of a 20 HP. under similar conditions. The test was repeated, and the plugs inspected at the conclusion of the idling period; they were perfectly dry.

The gear oil pump emitted a definite howl when the engine was accelerated in neutral. The difficulty of providing a quiet gear pump under load has apparently given the Daimler people a certain amount of trouble.

GEARBOX.
This is a four speed central change. The plunger springs maintaining the lever in position were too strong, making the change objectionable; this box is apparently somewhat worse than standard in this respect. The indirect gears were very noisy, roughly 100% more noisy than the 20 HP. four-speed box. Side shaft very fair.

CLUTCH.
Single plate dry clutch. This is a very good clutch. A standing start was made in top gear on a slightly up-hill gradient without any signs of shuddering. The clutch could be made to shudder with trick driving however. It struck one as
contd :-
  
  
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).


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