TOUGH GUY TECH TIPS

Correct Compression Ring Installation: Piston Ring Assembly Tip

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.

* Rings having no dots, bevels, or grooves can be installed either way.

Rings having a “pip” mark or dot on the side of the ring must always be installed with the “pip” mark or dot toward the top of the piston.

There are two styles of torsional rings with inside bevels, top inside bevel and bottom inside bevel. Always check for the dot.

Rings with a groove in the outside diameter and a “pip” mark or dot on the side must be installed with the groove toward the bottom of the piston and pip mark towards the top of the piston.

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


 

The engine’s oil economy was 8076 miles per quart (M.P.Q.).

The engine’s 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.

This represents a 53% decline on oil control with one ring of 6 incorrectly installed!

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 stroke 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.

Tough Guy Tech Tips: Piston Rings

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