Evening star., 1913-02-09
.HEAT|NG0F CYLINDER
Cooling Systems Puzzled Early
Engine Designers.
ITS CAUSES AND EFFECTS
Faulty Water Circulation Respon-
sible in Some Cases.
IMPROPER DRIVING ALSO
Makes Machine Labor Too Hard,
Which Is Equivalent to
Overlooking.

fernapS feW problems in the earlier
| days of gas engine manufacture puzzled
the designer more than cylinder cooling.
| This is. perhaps. not surprising when 1t is
remembered that the earlier internal COM
| pustion engineers gained their profess
sional knowledge in the steam engine
school. where the object aimed at was the
| retention of heat by inclosing the cylinder
| in jacket of exhaust steam, which nat
| urally had the reverse effect to that de-
sired in gas engine.
Although various cooling systems have
| been brought to high state of perfec-
ton. doubtless finality has not yet been
reached. and it is very questionable
whether the ordinary motor user-both
master and servant-has given that at
tention which he should to the cause and
effect of undue cylinder heating. 1t is an
acknowledged fact that overcooling is
undesirable, but the cases when it occurs
must form a very small percentage of the
whole. as the natural cylinder surround
ings and conditions all tend in the oppo-
site direction.
1t Is. however. with the problem Of
overheating that We are dealing and be-
fore diagnosing the causes We will first
study the effects.
The space occupied by gases of all kinds
is determined by their temperature and
as vaporized petrol is no exception to the
rule. this has a very important bearing
when considering motOr-driven vehicles
Inc cubical capacity of the cylinder,
other things being equal determines its
horsepower: such space must be charged
with the correct quantity of fuel, which
in turn must receive the treatment that
enables 1t to give the best results.
Defective Water System.
If the water circulating system is in
any way defective the cylinder becomes
overheated and the incoming charge ex-
panded beyond it's usual dimensions, so
that full quantity is not drawn into
the confined area.
Other things invariably follow over
heating. such pre-ignition and want of
compression, the fabrication is all upset
as an oil that may be an excellent anti
| friction element when subjected to a GER
tain heat naturally has its limit, and
when this is exceeded fusion takes place.
the lubricating properties are lost and,
instead of the piston rings taking an easy
sliding gas-tight travel up the cylinder
sides, a grinding frictional movement fol-
lows. In this way more heat is gener-
ated, until perhaps seizure takes place,
or. II events take another course a
broken connecting rod or crankshaft may
result.
Not sure Sign.
The fact of little steam escaping from
the radiator is not a sure sign that there
Is anything materially the matter. This
remark applies even with greater force in
hot climates in summer time. or where
continuous long runs have to be encOun-
tered with steep gradients.
Cheap oils are false economy; one
should only use a lubricant that carries
entire confidence. The writer had an in
stance recently with car which when
running slowly and using a low grade oil
showed loss of power. and though a care
| ful examination of the circulation and
lubrication systems proved all was in or
der, the trouble still continued. The Oil
was tested and found to be quite good for
! low temperature out almost valueless in
! nigh ones such as those met with in the
| class of engine we considering. as
almost the moment it entered the cylinder
IT was burnt up, SO that part of the pis
ton travelled in unubricated ground. De-
! poslts of carbon are much more likely to
/ accumulate under the adverse conditions
named. and eventually the carbon be-
comes an incandescent substance, giving
/ rise TO what is known as pre-ignition
/ easily proved by switching off the spark
! II pre-ignition Is taking place the engine
VIII continue to run so long as there is
vestige of life left in the carbon de-
! posits referred to- AS such action takes
! place before full compression has been
reached, it will readily be understood
| that an engine running under these con-
| ditions is eXtrava2ant In. fuel and wear
and weak as tractive agent.
Causes of Overheating.
Having mentioned some of the evil eff