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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).
Updates and changes to Sports' Phantom valves, springs, and fittings.

Identifier  ExFiles\Box 66a\2\  scan0063
Date  23th November 1927
  
Y8060

c. to Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}

BY/CS1/DB.{Donald Bastow - Suspensions}23112.27.

RECEIVED

Re EAC.14 - Sports' Phantom - Valves & Fittings, Sec:5060.

Please receive herewith prints of each of the following drawings:-

E.76986-Inlet Valve Guide, which replaces E.76704.
E.76987-Outer Valve Spring, which replaces E.76676.
E.76988-Exhaust Valve Guide, which replaces E.76703.

These details have been made to Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}'s request to give more coil clearance on outer spring, by lowering Spring Washer .075.

We would point out that the clearance between the bottom Spring Washer and the Core Plugs on Cylinder Head is very restricted, and should be watched when using the lowered washers.

If it is desired to try the existing Springs E.76676 along with the lowered washer on the Valve Guide, the following list shows the alterations to loads etc. obtained:-

LOADS.
Valve Open - altered from 68.75 lbs. to 63.75 lbs.
Valve Closed-altered from 40.65 lbs. to 35.8 lbs.

STRESSES.
Valve Open - altered from 53,500 to 49,000
Valve closed-altered from 31,850 to 28,000.

Total coil clearance is altered from .082 to .157 and clearance per coil is altered from .0117 to .0224.

When using the new Spring E.76987 along with the lowered washer, the loads etc. are unaltered from the original conditions to LeC.2479, except that clearance per coil when valve is open is increased from .0117 to .0224.

BY/CS.
  
  


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