Harrisburg telegraph. [volume] (Harrisburg, Pa.) 1879-1948, 1915-11-20
Knight Motor Advantages
Demonstrated by Pictures

H. II. Hover. who entertained a
large audience at the Engineers lee
ture room Thursday evening with an
Illustrated lecture on the WHY'S
knight sleeve-type motor, said in part:
THE design and operation of the
valves largely determine the success
of any motor. The valves must open
fully, to permit a maximum quantity
of fresh gas to enter the cylinders and
to allow dead" gas to leave the cylin-
ders; they must be tightly closed to
prevent any gas entering or leaving
the cylinders when gas is being COM
pressed and when the explosion is
taking place. And they should always
open and close at exactly the right
time.
The wide opening and positive
closing of it's sleeve valves make the
Knight motor superior to motors of
all other types.
I'm general, valves in automobile
motors are of two kinds-poppet
ivalves and sleeve valves, the former
being in most common use.
"A poppet valve is opened by a cam
Ia projection on a revolving shaft
which strikes 1t upward as the revo-
luton of the shaft brings the cam into
icontact with a push-rod below the
Istem of the valve. 1t is closed by a
spring.
I'm the Knight motor there are two
IsleeveS-round shells of cast iron-in
each cylinder, operating between the
cylinder wall and the piston-one
working within the other. Each of
these sleeves is raised and lowered
by connecting rod from an eccentric
shaft. This eccentric shaft is oper-
ated the same as the camshaft in a
lpoppet-Valve motor.
''In any mechanism the simplest de-
sign is invariably the most efficient
The fewer the parts, and the simpler
the operation. the less chance there is
for friction and wear. 1t is for this
reason and because positive action is
1 to be preferred, that engineers never
use springs and cams as an important
part of any mechanism except as a last
resort.
Consider now the construction of
the Knight type sleeve-valve motor as
compared with an ordinary poppet-
valve motor:
There are no stems in the Knight
motor to warp and wear - no springs
to weaken-no valves to pit and re-
quire constant grinding-no adjust
mentS to make.
The sleeve valves operate with
positive mechanical precision at all
speeds. Their operation is as posi-
tive as the valves in a steam engine.
| The operation of the poppet valve
is a constant hammering of steel on
steel. This hammering occurs at two
places-the cam against the stem and
the head of the valve against it's seat.
And the hammering occurs when the
valve is subjected to an intense heat,
for it's head is inside the combustion
chamber.
| Because of this hammering, the
very operation of the poppet valve it
| self causes it to warp and loosens the
valve in its seat,
There is no hammering in the
knight type motor. The sleeve valves
are raised and lowered by connecting
rods. Their action is regular. They
slide smoothly, between the piston and
cylinder wall, always covered with a
film of oil.
| In a poppet-valv motor compress
sion is held by the valves. The valves
operate against springs, and against
the resistance of gas. And to hold
compression the valves must fit
tightly.
Unlike the valves in a poppet-valve
motor, the sleeves in the Knight do not
operate against springs nor against
the pressure of gas in the cylinders,
for the sleeves in the Knight do not
hold compression. Because of this
the sleeves are not fitted tightly; their
surfaces are always covered with a
| film of oil and their whole travel is
less than one inch, at half the speed of
the motor-one-n ninth of the piston
travel; the friction resistance and
wear is negligible.
i wherever an explosion takes place,
carbon is formed. In poppet-valve
motor this carbon deposits on the
heads of the pistons and on the seats
and on the heads of the valves
This deposit of carbon eats into the
valves where they seat. This is known
as "pitting." And 'pitting" of valves
is one of the most common troubles
experienced with poppet-valve motors,
for this eating away causes leaky COM
preston.
Carbon, which forms so rapidly in
a poppet-valve motor as to seriously
affect it's operation and, therefore, ne
cessitates frequent cleaning, is barely
noticeable in a Knight type motor,
even after two or three years of SER
vice.
What little carbon does form is
beneficial. Indeed, the sleeve valves
in the Knight motor are designed to
encourage the deposit of carbon. To