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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).
Typed letter detailing the results of vehicle road tests and modifications.

Identifier  ExFiles\Box 11\2\  02-page088
Date  30th January 1929
  
47941
87

To: Hs.{Lord Ernest Hives - Chair}
From: G.W.H.

Hôtel de France,
Châteauroux,
Indre.

January 30th. 1929.

for Le CanadelHenry Royce's French residence. We have now completed the S.S. ready
We find that by fitting the front solid engine feet the torque reaction is more pronounced and has a sharper peak, this is at 17 M.P.H. Previously the torque reaction was at approximately 12 M.P.H. and of longer duration. At 70 M.P.H. the engine is now very rough and continues so up to 80/85 M.P.H. On the retard it keeps on to 65 M.P.H. We are disappointed in this, as at these speeds the engine was previously very smooth. The jellying of the front has been cured we should say 50%. Increased joggles on the steering are most noticeable, and at 65 M.P.H. they are at times bad. We have definitely proved that the oil leaks from the inside of the mechanic joints where the universal pins come through the case. To-day has been quite warm and we were surprised to find that it was necessary to open the radiator shutters full. It looks as if we may be in trouble with overheating as the weather improves and gets a hotter temperature.
We have not unfortunately had a chance to try out whether the alterations to the rear brake covers are successful or not, but we have been able to prove that we do not now foul these after altering the rear wing stays. We should like to make it clear of the inefficiency of the rear brakes. We have definitely proved this by chocking up the front brakes and the amount of pressure required to pull up with the rear brakes only is tremendous. Examination underneath shows ample lubrication to every part. We believe that we have made a 50% improvement in the loss of oil from the rear of the crankcase. To do so, we had the rear inner flange of the rear cover of the crankcase reduced 1/16 in its width, because we came to the conclusion that this flange was too near the throw-off ring on the crankshaft, there being in our case only .020" clearance. Also at the bottom of the top portion of this cover there was a flange that collected the oil. We have taken this flange out. Also on the bottom half there was no drain holes from inside the bottom cover to let the oil escape back in the crankcase. We drilled 3 3/16 holes through to drain this portion.

Re the 20-HP, We have refitted side engine guards and undershield ready for the car to leave on Thursday for Derby. We had started to investigate for improved undershielding. We have been informed by letter from Paris that the papers will be at le Havre and everything should be O.K. for shipment of the car.

G.W.H.
[Signature]
  
  


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