The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1922-01-15

Q. What determines the firing or
der of a four-cylinder engine and
what are they? Please apply the
same question to a six-cylinder en-
CINE.
A. The two firing orders avail
able on a four-cylinder engine are
-2-4E3 or 1-3-4-2. The Sc
lection of which depends upon the
order of valve operation. On a six
cylinder engine the crank shaft de-
termines the two firing orders which
may be 1-5-3-6-2-4 or -
2-6-sI5 and then the order valve
operations determines the order Sc
iected.
O. Some one told me that scrap
ing bearings is a very hard job and
for me not to tackle II. 1 have me-
chanical ability and have been told
how to do ii. Do you think / could
get away with 1t?
A. Yes. IL you are careful and
have enough patience to do a good
job, go after 1t. In taking on the
connecting rods be sure and mark
the upper and lower bearing caps
so that they go back in the same
position, Blue the crank pins and
carefully scrape bearings to ft.
Good luck to you.
@. What is the meaning of the
word cycle and what Is a four
cycle engine?
A. Anything in continual opera
ton repeats itself That portion
which is repeated is a cycle. The
reference "four-cycle engine" is
really incorrect. 1t should be re-
ferred to as a "four-stroke cycle en-
CINE" meaning that it requires four
strokes to complete one cycle of
action in any one cylinder.
/ Q. What is meant by valve clear
ance and how can a car owner
check same? Is il important for
such adjustment to be accurate?
A A valve litter which rides on
the cam shaft strikes the valve
stem and lifts the valve off its seat
at exactly the proper intervals.
There must be a small clearance
between the valve litter and stem
because when they become heated,
expansion takes place and with no
clearance the valve wouldn't seat
with a resulting loss of compress
sion. A set of thickness gauges
can be purchased which consists of
thin sheets of metal of varying
thicknesses. By placing a gauge of
proper thickness between valve
litter and stem and adjusting, very
accurate clearance can be arrived
at. In doing this work It is well
to get a manufacturers instruction
book and get the valve elegance
from there.
Q. What is the action of the Ford
timer and does it need any atten-
ton?
A. The timer closes the primary
circuit at the proper intervals TO
secure a spark in the various evil
inders at the proper moment. 1t is
very important that the timer be
Kept in good condition because good
ignition depends very much upon n
slightly worn timer that causes
a scarcely perceptible miss may
decrease efhciency as much as three
lnnes per gallon Of gasoline. Take
II on ana clean IL at least once a
week. Oil it slightly every day.
me timer on a Ford car causes
more trouble than any other unit.
Keep II clean and you will avoid
niue annOyanceS.
y. What is the difference he.
tween the vibrating coil and a sin
gle spark coil?
A On a single spark system
mere Is but one spark at the ming
ana this when the contact points
open at the instant of separation
or break. This Is usually sufficient
put IL Is Of advantage to have a
shower or series of sparks Instead
Inc vibrating coil as used on a
Ford Is producing a high-tension
spark all the while 1t buzzes ana
therefore when working properIv
insures better ignition.
2. How can one quickly deter.
mine the firing order of a four or
six cylinder engine?
A. II the cylinders printing mr.
compression relief cocks Installed
put wads of paper or waste In the
cups and turn the engine over and
watch the order In which thew blow
out Removing spark plugs and
checking the order of compression
can also be done. watching Inc
order in which the exhaust valve,
open viii also Indicate The firing
order. In a later issue an easy
method Of quickly determining the
order of eight and twelve cylinder