wrist pin bushings

[f balsiger]

I am confused , what holes do I drill in a wrist pin bushing?

[Kurt in NJ]

the center boss was for manufacturing, though many times I have seen them drilled, also the bushings have to be expanded to form to the rough bore and so they don't come loose, originally the bushing was 2 with a groove in the center for the wristpin clip
the outer 2 holes originally were drilled

[ursus]

The fundamental question is whether or not the wrist pins need holes for oiling. I have replacement bushings supplied by Ford (in original Ford boxes) that are a straight bushing with no holes drilled to match the holes in the rod. Most of the rods I have pulled from worn engines had bushings with holes to match the drillings in the rods. For years, the parts suppliers only carried bushings with holes but now they seem to only have undrilled bushings. What is correct or does it make any difference?

[Kohnke Rebabbitting]

Originally Posted by ursus

The fundamental question is whether or not the wrist pins need holes for oiling. I have replacement bushings supplied by Ford (in original Ford boxes) that are a straight bushing with no holes drilled to match the holes in the rod. Most of the rods I have pulled from worn engines had bushings with holes to match the drillings in the rods. For years, the parts suppliers only carried bushings with holes but now they seem to only have undrilled bushings. What is correct or does it make any difference?

New bushing should not have holes already drilled. They are always drilled after, or you would have an alignment problem when pressing them in.

yes they have to be drilled, for oiling.

The wrist pin to bushing should be fit with .000-50 thousandths fit, ONLY.

The last thing, after the pins are fit, check the rods for twist, bend, and offset Alignment!


Herm.

[Joe K]

The wrist pin to bushing should be fit with .000-50 thousandths fit, ONLY.

I'm sure this is a "fat finger" mistake. That is .000 to 0.0005 fit. (5 ten-thousandths)

Pretty precise and that is why most bring their pistons & rods to a shop to have them fitted using an hone.

Joe K

[BRENT in 10-uh-C]

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Originally Posted by Joe K

I'm sure this is a "fat finger" mistake. That is .000 to 0.0005 fit. (5 ten-thousandths)

Pretty precise and that is why most bring their pistons & rods to a shop to have them fitted using an hone.

Joe K

The hone is only the half of it. That is why we also have/use an AG300 or equivalent.