How To Rebuild Your Ford V-8 351C-351M-400-429-460.pdf - Index of

1
Oil rings are easy, but tricky to install. After
the expander-spacer, top rail goes on next.
Now's the time for checking the expanderspacer
ends. They shouldn't overlap. If
they the rail9 'Orrect the
Two ways of installing a compression ring-with thumbs or with an expander. If you elect
problem and reinstall When installing a
not to use a ring expander, be careful. It's easy to bend or break a ring. If this happens you
its free end it scratch could've saved money by purchasing and using an expander. Regardless of how you elect
the piston as YOU bring it down over the
to do it, remember the pip marks go up,
piston and into its groove. - Position the rail
and gaps now.
tool for the oil-ring components-the expander-spacer
and the two side rails.
However, you can save yourself some
time later on by installing the three rings
which make up the oil-ring assembly so
their end gaps are in the right relationship
to one another rather than waiting
until it's time to install the piston and
rod in its bore. The idea is to stagger the
gaps so they don't coincide with each
other. If this were to happen the oil ring
could pass excessive amounts of oil.
The piston front is shown by a notch
or arrow stamped in its dome. A cast
piston has the notch, and a forged one
has an arrow. The drawing on page 103
shows how to position the end gaps for
all rings. Install the expander-spacer with
its gap directly at the front of the piston.
Its job is to locate the two rails in the oilring
groove. Be careful when installing
the expander-spacer. Make sure its ends
butt and don't overlap. You really have
to work at keeping this from happening
with some expander-spacer designs.
Now you're ready for the rails. Insert
one end in the oil-ring groove on top of
the expander-spacer. Hold the free end
of the ring with one hand while running
the thumb of the other hand around on
top of it to slip it into its groove. Don't
let the free end of the ring dig into the
piston as you bring it down over the
piston and into its groove. Install the
other rail below the expander-spacer
using the same method. Position the rail
gaps as shown in the drawing. Doublecheck
the expander-spacer to make sure
its ends aren't overlapping.
Wlplng cylinder bores to remove any dust
or dirt which may have accumulated. Don't
use a cloth towel or rag, use a paper towel.
Compression Rings-Compression rings are
much simpler in design, but more difficult
to install than oil rings because they
are stiff. They are easily damaged, and
can damage the piston during installation
if done incorrectly. Keep your eyes
open when installing these guys. Look
for the "pip" mark-a little dot or indentation-which
indicates the top side of a
compression ring. The pip mark must be
up when the ring is installed, otherwise
the twist will be in the wrong direction,
causing excessive blowby and ring and
ring-groove side-wear.
Twist describes how a ring bends, or
the shape it takes in its groove. Twist is
used for oil control and for sealing combustion
pressures. Compression rings with
no twist have no pip marks. If you get a
set like this, although it's unlikely, you
can install them either way. But inspect
the rings to be absolutely sure. Also,
read the instructions which accompanied
the rings and follow them exactly.
The difficult thing about installing a
compression ring is spreading it so it'll
fit over the piston while not twisting or
breaking the ring or gouging the piston
with the ring ends. This is why I recommend
using a ring expander.
There are different styles of ring expanders.
The top-of-the-line type has a
circular channel for the ring to lay in while
it is expanded. The less-exotic expander
doesn't have this channel. You have to
use one hand for expanding the ring while
controlling the ring with the other, Regardless
of the type you have, don't
spread the ring any more than necessary
to get it over the piston. Install the
second (lower) omp press ion ring first.
Make sure the pip mark is up, expand the
ring while making sure it doesn't twist
and install it over the piston into the
second groove. Do exactly the same with
the top ring, installing it in the top
groove. End-gaps on these two rings
should be placed as shown in the drawing.
Check them for position immediately
before installing the piston in the engine.
You may decide to install your compression
rings without the aid of a ring
expander, so I'll tell you how to do it
right. Wrap the ends of your thumbs with
tape. The sharp ends really dig in when
you're spreading the ring. Position the
second compression ring over the piston
with the pip up. Rotate the ring over the
edge of the piston so its ends are lower on
the piston than the rest of the ring. With
your thumbs on the ends of the ring so
you can spread it and your fingers to the
side for controlling it, spread the ring
and rotate it over the piston with the