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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).
Engine component design, materials, and wear issues, referencing Cadillac and Ford.

Identifier  ExFiles\Box 132\5\  scan0137
Date  25th April 1940
  
Rm{William Robotham - Chief Engineer} - 4.
Serial No.102.
OY:S/D/Apr.25.40.

Their latest Feroxed Perfect Circle ring makes bore wear measure-
ments an "exact science". These rings are flat honed on the
faces to permit free motion in the grooves under pressure.

What is worrying Cadillac now is how to get "bad" iron
in the bores at the upper end, where the pressure in the mold
normally gives them a close grain structure.

On L-head engines the upper end of the bore in the
immediate vicinity of the exhaust valve becomes expanded inwards
towards the piston by the heating effect of the flame travelling
out through the valve, as can be seen through the quartz window.
They would like to get rid of the resulting hard bearing, don't
how, and would welcome suggestions.

It is climbing this lump on the bore which makes
the rings tired.

A similar effect occurs in the Ford liners, but
here the entire valve side of the upper end of the liner expands
till it is compressed beyond the elastic limit, then straightens
out when it cools and tries to lock the pistons. Carbon fills in
back of the liner and adds to the trouble.

Valve Guides.

Cadillac are trying these in sintered cast iron,
which proves to be ideal metal for the job. (Now used for oil
pump gears). Cadillac are only doubtful of mechanical strength
of this metal for insertion, but, if this is poor, the guides can
be carburized and hardened or heat-treated on the O.D. The doubt
at the moment is whether supplies of Swedish iron ore are adequate
for sintered cast iron. Required a pure ore, as the material is
never melted.

Valve Seats.

Cadillac do not use valve seat inserts. Say these
run too hot. (Heron says, not if properly designed and inserted
and probably the valves might do better to run a bit hotter).
Cadillac say that with Wilcox-Rich valve lifters the seat damage
is so small that inserted seats are unnecessary on car engines.

Tappets.

C.I. Feroxed tappets do an excellent job. Must
send you a sample.
  
  


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