Tulsa daily world. [volume] (Tulsa, Indian Territory [Okla.]) 1905-1919, 1918-05-26
Designers of Cylinders Fol.
lowed Models Used in Eu-
ropean Countries.
HAS HALL-SCoTT CAM SHAFT
Delco Ignition System Espe-
cially Designed to Save En-
gine Weight.
12-CYLINDER CRANK SHAFT 7
Economical Use of Oil In
Standardized System for
fabrication.
HAS HALL-SCOTT CAM SHAFT
12-CYLINDER CRANK SHAFT 7

The war department has issued
the first authorized statement re
garding details OF construction OF
the Liberty motor. II discloses that
the Liberty motor was a comoina7 u
tion of many motors. The statement
reads.
The designs OF the parts of the
Liberty engine were based on the
following:
"Cylinder-The designers of the
cylinders for the Liberty engine fol,
lowed the practice used in the Ger
man Mercedes, English Rolls Royce,
French Lorraine Dietrich and Ital-
Ian Isotta Fraschini before the war
4 and during the war The cylinders
are made of steel inner shells, sur
rounded by pressed steel water
Jackets. The Packard company by
long experiment had developed a
method of applying these steel water
jackets. The valve cages are drop
forgings welded into the cylinder
head. The principal departure from
European practice is in the location
of the holding down flange. which
is several inches above the mouth OF
the cylinder and the unique method
of manufacture evolved by the Ford
company. The output is now APP
inder' forgings per day.
Cam Shaft and valve Mechan-
ism Above Cylinder Heads--The de-
sign of the above is based on the
Mercedes, but was impr oved for
automatic lubrication without vast
ing OIL by the Packard MotDt Car
Company.
Cam Shaft prive.-The carr
shaft drive was copied almost en-
tirely (. ON the Hall-Scott mN'oc N
fact, several OF the gears used in the
first sample engines were supplied
by the Hall-Scott Motor Car .om-
pany. This type of drive is used by
Mercedes, Hlspano 'Suiza and others
Angle Between Cylinders.
Angle Between Cylinders-In the
Liberty the included angle between
the cylinders Is As degrees in all
other existing 12cylnder engines fl
Is sixty degrees. This feature is
new with the Liberty engine, and
was adopted for the purpose ci
bringing each row of cylinders
nearer the vertical and closer to.
sether' so as to save width an1 head
resistance. BY the narrow angle
greater strength is given to the
crank case and vibration Is reduced
Electric Generator and Ignition
"A Delco ignition system is used. II
was especially designed for the Lib
erty engine. to save weight and 10
meet the special conditions due 10
firing II cylinders, with an Included
angle OF As degrees.
"Pistons-The pistons Of the III.
erty engine are of Hall-Scott design.
Connecting Rods Forked or
straddle type connecting rods, first
used on the French De Dion car
ana on the Cadillac motor car in
TINS country, are used.
Crank shaft--Crank shaft design
IoIloWed the standard l2-cylinder
practice except as to oiling. Crank
case follows standard practice. The
40 degree angle and the flange loca-
ton on the cylinders made possible
very strong box section.
Lublication.
"Lubrication--The first system of
lubllcauon followed the German sys-
TEN of using one pump to keep the
crank case empty. delivering into an
outside reservoir, and another
pump to force oil under pressure to
the main crank shaft bearings. This
fabrication system also followed the
German practice in allowing the
overflow in the main bearings TO
AA"'Ni 'ut tiif idNt OF tHe crank
cheeks to a scupper. which collected
this excess for crank pin lubrica-
tion. This is very economical in the
use of oil and is still the standard
German practice.
Tho present system is similar to
the first practice, except that the
oil. while under pressure, is not
only fed Ia main bearings, but
through holes inside Of crank checks
TO crank pins, instead Of feeding
through scuppers The difference
between the two oiling systems con-
sists Of carrying oil for the crank
pins through a hole inside the crank
cheek. instead Of up the outside
face of the crank cheek. O.
Propeller hub:-The Hall-Sco
propeller hub design was adopted to
the power of the Liberty engine.
Water Pump--The Packard type
Of water pump was adapted to the
Liberty.
'Carhuretor-A carburetor . was
developed by the zenith company
Tor the Liberty engine.
Bore and Stroke-The bore and
stroke of the Liberty engine is SKI
inches, the same as the Hall Scott
40 and Al engines and as in the
HaIl-Scott 12-cylinder engine.
Development Ideal.
'Remarks-The idea of develop
Ing Liberty engines of four stN,
eisht and 12 cylinders with the
ABOVE characteristics was first
thought of about May 25, 1917. The
laea was deYeloped in conference
W'th representatives OF the British
ana French missions May 2S to
June !. and was submitted in the
form of sketches at a Joint meeting
oL the aircraft (productionJ board
ana the joint army and navy tech
MI board June 4. The first sample
was an elght-cylinder model. deliv-
erel to the bureau of standards July
., 1917. The eight-cylinder model.
however was never put into pro
Gneuon, as advices from France in
created that demands for Increased
power would make the elght.cyij
ger model obsolete before it could
be produced. ~0u'N
work was then concentrated on