Ring installation instructions
are placed in every set of piston rings Hastings Manufacturing
Company produces. These instructions should be read
each time before the piston rings are installed on the
pistons. Listed below are the general rules for the
installation of various types of compression rings.
having a "pip" mark or dot on the side of
the ring must always be installed with the "pip"
mark or dot towards the top of the piston.
Rings with a bevel on the inside
diameter but no "pip" mark or dot must be
installed with the bevel towards the top of the piston.
Rings with a groove in the outside
diameter and no "pip" mark or dot must be
installed with the groove toward the bottom of the piston.
* Rings having no dots, bevels,
or grooves can be installed either way.
It is a good idea after installing
all rings on the pistons to recheck each ring on each
piston for correct installation.
To illustrate what can happen
with just one ring installed upside down Hastings installed
a new V-6 engine on a dynamometer in our engine test
laboratory and ran the engine for 80 hours with all
rings installed correctly.
Figure 1 shows the correct position
of the reverse twist taper face compression ring.
The engine's oil
economy was 8076 miles per quart (M.P.Q.).
The engines oil pan, one
head, and one piston were removed and the second compression
ring was turned over so the dot was facing the bottom
of the piston. Figure 2 illustrates the incorrect position
of the ring.
The engine was re-assembled and
ran again for 80 hours on the same schedule as the prior
test. This time the oil economy was 3802 M.P.Q. Figure
3 shows this graphically.
a 53% decline on oil control with one ring of 6 incorrectly
Figure 2 also contains the reason
for the poor oil control. With the taper of the ring
upside down, oil will be scraped up with each upward
strode to be left in the combustion chamber and burned
on the power stroke.
It only takes a minute, check
all rings on the piston for correct installation before
installing the pistons.
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