El Paso herald. (El Paso, Tex.) 1901-1931, 1918-05-25
TYPES OF ENGINE CYLINDERS
ATTRACTING MORE ATTENTION
Shape Is Factor in Determining Valve Locations and
in Conserving Heat; Valve-in-Head Type Growing
in Favor: War Bars Broad Use Of Aluminium.

ONE OF the most Interesting Of the
" parts employed in the automobile
engine Of today is the cylinder.
Strangely enough in this fundamen-
tai part, designers have found an op-
iportunity for developing almost end
I less differences Of opinion with re-
spect to materials. shape, angle Of To-
cation. method OF cooling, numbers,
etc. II is this variety OF type that
makes It worth study.
While the cylinder perfoms a pas
slye function, so TO speak, Il must not
be assumed that It has a sinecure.
While Il does not move in performing
its duties. its uppear area must act
as a combustion chamber and be sub
Ject 10 intense heat IL must house the
valves. act as a guide for the opera
7 ton Of the piston and provide for the
mounting Of the fan bracket. mani
fold and sometimes Of other parts.
Four Distinct Types.
The major classification OF cylin-
ders is according TO their shape. which
determines to a large extent the valve
location. The ordinary forms are the
L-head, the T-head, the valve I'm the
head and the sleeve valve or Knight
type. The other types, rotary, revOlv-
ing cylinder. etc. are not in use In
modern automobile power plants and
so DO not interest Us al present The
first two types have obvious names.
The L-head type when seen in cross
section looks like an inverted l. In
the T-head a section is like the letter
T. In the T-head engine the inlet and
exhaust valves are located at opposite
sides Of the cylinder. This necessi-
tates the use Of two camshafts. one
for the inlet valves, the other for the
exhaust valves. in the engine which
has the valves located in the head OF
the cylinder. the valves are operated
through rods and rocker arms. or else
an overhead camshaft is used. The
sleeve valve engine employs sliding
sleeves with appropriately located
ports TO let the fuel in and the eX-
haust gases out. instead OF the Ia
miliar pOppet valves.
These are the fundamentally differ
ent classes. but there are minor Vari-
ations. which permit OF still more
detailed groupings Al instance OF
this is found IN an engine embody-
ing the L-head cylinder, in which one
set OF valves is located in the usual
place IN the side The other valves.
however. are placed directly in the
head and are operated by rods with
rocker arms as in the ordinary type
Of valve-in-head power plant.
IN the valve-in-head engine. there
are a number OF different methods Of
placing the valves Sometimes these
down vertically into the combustion
chamber. Again they may be placed
horizontally in the cylinder head In
other cases the valves may be located
in the head at an angle from the YER
teal
should Hold Heat.
One Of the fundamental problems
confronting the designer Of a cylinder
is TO keep the combustion chamber
as nearly spherical as possible, in or
der 10 reduce to the last de-
gree the heat loss through the wallss
for be IL remembered that heat is
power and good design retains all
the heat consOnant with safe opera
tion. Obviously the L-head and T.
head types OF cylinders approach this
sphericity only approximately. The
vaIve-in-head cylinder and the sliding
sleeve type on the other hand, achieve
an approximate approach 70 perfec-
ton in this respect The elimination
OF the sockets in the combustion
chamber OF the engine contribute TO
exactness Of combustion chamber vol
ume-
There is a general impression that