Piston wrist pin question

[wrndln]

I am using Timesaver to lap in the babbitt on the mains and rods and ran into something I am not sure is right or wrong. Number 1, 3 and 4 piston rods wrist turn on the wrist pins, however number 2 piston wrist pin turns in the piston, not the rod. I can move the rod back and forth with a little force, so it isn't stuck or frozen to the wrist pin, just a little tight it appears. I always thought the rod should rotate on the wrist pin. Is there a problem with the wrist pin rotating on the piston verses the rod? Maybe when the engine is started and run some, the rod will start turning on the wrist pin, however I wouldn't be able to tell if it did or not. BTW, the engine machine work was done about 20 years ago (babbitt, boring, rod machine work, new pistons and wrist pins, etc.) and the engine has never been run in the current configuration. Thanks for any advice.

 

[RichPA]

This is a "floating pin" design meaning the pin will rotate in the pin or the piston, or both. I beleive after some run time everything will "float"

 

[MikeK]

So why put it together and then worry? Instead, take it apart and check it out. Look for shiny burnished high spots in the rod bushing, dress them out a little.

 

[d.j. moordigian]

Rusty,

The pistons to pin fit should be a " lite thumb press ",at the tightest, as the piston warms up it
will free up. The pin to rod clearance is .0004 to .0005, the rod and pin grow at the
same rate. Count the " 0 " this is a VERY close tolerance.

Hows the car coming, Dudley