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Old 12-15-2009, 09:21 PM
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Join Date: Mar 2002
Location: So Cal
Posts: 919

Be VERY careful when you install the new piston and ring. The piston will have a ring alignment pin in the ring groove and you MUST install the ring so the gap is aligned with this pin. You'll see the tips of the ring are relieved to allow the ring to fit over the pin.

If you install the piston with the ring improperly aligned, the pin will get forced deeper into the piston, and the alignment of the ring gap is basically out the window. The purpose of the alignment pin is to keep the ring gap in the same position, which is on a portion of the sleeve where there are no ports. If the ring isn't fixed in that position, it's only a matter of time before the ring rotates and gets stuck in an open port and KABOOM.

I saw more of these truck engines destroyed because many owners wanted to take the engine apart to have a look inside. They failed to realize that the ring alignment was critical and they blew the engines within the first few minutes of running.
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