239 rod holes

[clark51]

I recently started to rebuild my 1951 F1 239 and noticed that 7 of the 8 connecting rods have two 1/8" holes drilled through the top of the small end. Number 7 rod doesn't have any holes drilled in it. Are these holes for balancing, lubrication or both? As far as I can tell this engine has never been taken apart. Any help is appreciated. Thanks

 

[rotorwrench]

The small end bushings need oil too. They should have two oil holes, one on each end. Is the one completely undrilled or is it that the bushing doesn't have a holes through?

The later ones from mid 1950 or so, should have a little hole on the big end that aims at the bottom of the piston and acts as a piston cooling/lubrication squirt.

 

[Glenn Thoreson]

The small hole is for lubricating the wrist pin. One odd rod indicates the engine has been repaired at one point in time. I don't think drilling it would remove enough metal to affect balance.

 

[Ross F-1]

The change was made for '50, those are "0BA" rods. It's additional lube for the cam, what I read.

 

[clark51]

There isn't any holes in the bushing or the small end of the rod. It doesn't seem to be worn any more than the other bushings.

 

[rotorwrench]

Condition is contingent on how long it was in service. If it is original to the engine then it was a factory screw up. Even Ford's quality control wasn't always perfect. I would want the oil holes in there myself just for the sake of reliability and uniformity. A person can get the con rods all checked if they are planing to balance the rotating assembly. Some folks balance and some don't. A swap out with a serviceable matching con rod would likely settle any worry about balance.

 

[clark51]

Thanks for all the info. I have a spare 239 flathead from a 50 Mercury 3/4 ton. They all have 2 oil holes in the small end. I think I could use them or make one good set out of the two.