59AB crank using 8BA con rods.

Robert Dip

Robert Dip

Senior Member
Can 8BA con rods with insert bearings be used on an earlier crank...59AB. Are the oil holes on the crank compatible with the 8BA rods. Thks.
 
The 59A crankshaft rod bearing oil hole is located in the center of the journal the early connecting rods use floater rod bearings which are the width of the journal so only one oil hole is needed.

The 8BA crankshaft has two oil holes on the rod journal the connecting rod bearings are narrow only the width of the rod so the two oil holes are needed. The center oil hole in the 59A crankshaft will not lubricate the 8BA rod bearings the oil will just leak out between the 8BA rods.
Ronnieroadster
 
The answer is YES, and for some reason it works. I don't recommend it. It was don on the fire truck in saxton river about 30 years ago and the dam thing is still running. It also worked in a junk engine I made up just tho have a runner in an old truck back in the 60's. I;ve often thought of the reason why. If the rods have stock side clearance why nor. 10/20 lbs of oil pressure is more than enought o run a flathead. That,s what they were designed for 10 w in the winter and 30w in the siummer. Might work, migh not.
Gramps
 
I cannot say I recommend it. However, I examined an engine from a high mileage 46 pickup which had 8BA rods on the 59A crank and I saw NO problems with the insert bearings nor the crank journals. So, this is not absolutely as clearcut as we might think.
 
The problem here is: "NO" is based on the design of the oiling system. Many years ago most engines were lubricated with the "Splash" system. no Body has ever done an investigation on the lubricating quality's of the single hole crank and incert bearings. However, that doesn't make it right, but to say it wont work, is just a guess.
Gramps
 
Ol' Ron said:
The problem here is: "NO" is based on the design of the oiling system. Many years ago most engines were lubricated with the "Splash" system. no Body has ever done an investigation on the lubricating quality's of the single hole crank and incert bearings. However, that doesn't make it right, but to say it wont work, is just a guess.
Gramps
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While one would think you have a point. My question is this why would Ford waste the time and money to drill two oil holes in the 8BA crankshaft when one hole would work? Next question could it be during testing it was determined it was not a good idea? We know any additional expense would have never been allowed in production if this improvement was not needed just think of the thousands of dollars wasted adding an additional hole.
The answer to the original posters question is still NO
Ronnieroadster
 
Appreciate it....this is a Canadian engine...so, I;ll have my buddy ( his engine ) look into this if it has the two drilled oil holes.
 
Ronnieroadster said:
While one would think you have a point. My question is this why would Ford waste the time and money to drill two oil holes in the 8BA crankshaft when one hole would work? Next question could it be during testing it was determined it was not a good idea? We know any additional expense would have never been allowed in production if this improvement was not needed just think of the thousands of dollars wasted adding an additional hole.
The answer to the original posters question is still NO
Ronnieroadster
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Hi Ronnieroadster; The designers may have just assumed each bearing needed it's own oil source, I believe most of us would. To error on the side of caution I'm on the no side, but is interesting that it has worked, Craig.
 
I didn't say it's the right thing to do, and it probably wouldn't work in one of your Bville engines, and the right answer is "NO" but if you had no other way to do it, at keast you know the flathead can do anything. Don't you just lov them.
Gramps
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