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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).
Issues with exhaust valve seatings in a cylinder head, leading to loss of compression.

Identifier  ExFiles\Box 11\5\  05-page158
Date  11th September 1934
  
x7941

Hotel de France,
Chateauroux. Indre.
France.

To Hs.{Lord Ernest Hives - Chair}
From G.W.H.
c. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}

11th September 1934.

28 - EX
Exhaust Valves.

In your memo Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer} 19/MJ. 10/8/34 you stated that the exhaust valves of Nos. 2, 6 and 10 were stellited and fitted with seatings in N.M.C. We have dismantled the cylinder head owing to loss of compressions on Nos. 1, 2 and 5 cylinders. The compressions were escaping past the exhaust valves. The valves do not show any burning or distortion of the seats, but the N.M.C. seatings in the cylinder head have distorted considerably, also they have gone less in diameter, i.e.- shrunk from the aluminium, a distinct space being observable round half of the outer diameter of the seating plug. The inner diameter also is smaller and the valves are hammering a ridge in at the bottom of the seatings; checking the bedding of the valves shows only a very small portion of the seat making contact.

G.W.H. GWHancock
  
  


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