Rolls-Royce Archives
         « Prev  Box Series  Next »        

Report estimating the variations in tappet clearance for an overhead camshaft engine due to temperature effects, comparing a Standard Head and a Ramp Head.


Identifier  ExFiles\Box 133\2\  scan0162
Date  2nd July 1935
  
To Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer}

King (handwritten)

Hs {Lord Ernest Hives - Chair} /Smth.12/KW. 2.7.35.

Overhead Camshaft Engine.

Variation in Tappet Clearance.

From measurements we have made on a Bentley engine, we estimate that on an overhead camshaft engine of Bentley size with an aluminium head, the following would be the variations in tappet clearance due to temperature effects :-

Standard Head.

Table 1:
Headers: Exhaust Valve, Inlet Valve
Sub-headers: KE.965, Silchrome, Silchrome
Row 1: Starting Up, - .005, - .0035, 0
Row 2: Engine Hot, - .0015, + .0015, + .003

Ramp Head.

Table 2:
Headers: Exhaust Valve, Inlet Valve
Sub-headers: KE.965, Silchrome, Silchrome
Row 1: Starting Up, - .005, - .0035, 0
Row 2: Engine Hot, + .0005, + .0035, + .005
  
  
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).


Copyright Sustain 2026, All Rights Reserved.    whatever is rightly done, however humble, is noble
An unhandled error has occurred. Reload 🗙