The sun. [volume] (New York [N.Y.]) 1916-1920, 1919-05-18
FITTING CARS
PISTON RINGS
Useful Information to Owner
Who Works on His
Own Car.

It has been mentioned repeatedly in
these columns that much OF the trouble
caused by leakage of oil and mixture
past the piston rings was due in the
greater number OF cases to III fitting
rings rather than to the rings them
selves. A piston ring of fairly good de-
sign poorly fitted is as bad as a poor
ring. II the repair shop and the owner
would spend a little more time and
money having the proper rings properly
fitted, better engine performance. better
economy and freedom from many en-
gine troubles would result. Without 60
ing into the action that occurs when
rings fit poorly, We shall take UP the
steps In fitting new rings.
We will assume that the cylinder
block ia removed and the piston removed
from the connecting rods The FIRST step
Is to take the new rings and fix the
end clearance. This Is done by placing
tho ring inside the cylinder and measur-
ing the clearance at the ends. This will
vary somewhat In different engines and
may be anywhere from DOT to .015. IT
will be necessary to get the exact figure
for the particular engine from the manu-
facturer or dealer. II the clearance Is
not enough, the ring ends are fled with
fine file.
The next step is to prepare the piston
for the acceptance of the rings 1t is
essential that two conditions exist-the
grooves must not only be clean but they
must be true. Grooves of one width in
one place and another a few inches away
cannot possibly be htted correctly. The
grooves must be true in width and depth
all around and this requires measuring
them accurately. In some cases the
grooves are fled to make them true. but
an easier way is to use a regrooving tool
and eliminate this uncertainty and
trouble. Regardless of the method used.
see to 1t that the grooves are clean and
true all around.
The rings now are taken one at a
time and fitted into their respective
grooves. Work from the bottom to the
top OF the piston. Take hold Of q ring
and place its back end in the groove
and roll II around. This is an initial
check to determine whether the ring will
60 into the groove. It either fits in one
Of three ways-it Is either too wide to
go into the groove. SO loose that play is
felt. or It "just fits"-that is, It may be
rolled around and no play Is felt. The
latter Is the best, but a ring too wide
can easily be Tapped down to the right
width.
This Is done by rubbing the ring over
an abrasive such as emery cloth or
emery dust and oil. The abrasive Is
placed on a level plate and the ring
carried over It with one hand; or q
block of wood may be used. Lap only
little at a time and after each tapping
clean the ring carefully in gasolene. dry
1t and try It in the groove again-back-
ward, as before. II It may be rolled
around with much difficulty It may
be slipped over the piston into its groove
for another test. To slip the ring ir
place use three pieces of an old saw
blade or similar metal pieces to act a,
skids Hold one skid against the side
of the piston and slip the ring over thai
skid, then while 1t is caught In thai
position slip another skid between
piston and ring. Move the second skit
about one-third around the piston. TheI
third skid may be slipped in plac,
and the ring slipped down over thu
three.
After the ring Is seated in its groove
grasp II firmly with one hand and NOV,
1t around three or four complete turns
II 1t sticks In Its groove the Mt Is to-
tight II there is up and down pla!