The Ford Barn

clark51 · 01-29-2018, 10:56 PM

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 · 01-30-2018, 11:47 AM

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 · 01-30-2018, 08:47 PM

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 · 01-30-2018, 10:25 PM

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

clark51 · 01-30-2018, 11:14 PM

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 · 01-31-2018, 02:06 PM

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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 · 01-31-2018, 06:13 PM

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.

01-29-2018, 10:56 PM	#1
clark51 Junior Member Join Date: Feb 2017 Posts: 18	239 rod holes 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

01-30-2018, 11:47 AM	#2
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: 239 rod holes 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. Last edited by rotorwrench; 01-30-2018 at 01:29 PM.

01-30-2018, 08:47 PM	#3
Glenn Thoreson Senior Member Join Date: May 2010 Posts: 203	Re: 239 rod holes 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.

01-30-2018, 11:14 PM	#5
clark51 Junior Member Join Date: Feb 2017 Posts: 18	Re: 239 rod holes 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.

01-31-2018, 02:06 PM	#6
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: 239 rod holes Sponsored Links (Register now to hide all advertisements) 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.

01-31-2018, 06:13 PM	#7
clark51 Junior Member Join Date: Feb 2017 Posts: 18	Re: 239 rod holes 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.