Main bearing question

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GlennB4u

GlennB4u

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I seem to have an oil pressure problem after getting the engine to operating temperature. I've done a little reading and things point to worn bearings... main, rod and cam. I thought I'd pull my pan and take a look. I have no idea how the engine was taken care of before I got it, but the pan had a 1/2 inch of sludge in it, even after I cleaned it a few months ago...so that concerns me. The main bearing is pretty worn for sure. Does anyone see that this crank will need turned at all or can I save it?
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Hard to tell from a picture. As long as the journals are smooth you should be ok. Best thing to do is pull the crank and mic all the journals to be 100%
 
I think you need to pull it to determine the condition.
 
How long do you need the engine to last?
Those bearings are shot, and can you catch a finger nail on the crank journal?
And does the oil pump pick-up sound like a baby rattle.
A fresh set of bearings, oil pump, and clean the pickup screen might get you a few more miles out of it.........
 
When I was a kid I knew a guy, John was his name. He had a newspaper route that he worked with his Renault Dauphine. Went with him one night on his paper route, and while still 25 miles from home, the Renault starting rattling and losing oil pressure. He pulled over to the side of the road and said, "Don't worry. It does this all the time." He jacked it up and drained the oil, pulled the oil pan and figured out which bearing had let go. Went to his trunk and got out a box full of bearings. Installed another bearing for the bad one, put the pan back on and reinstalled the old oil. We finished the route and got home fine.

You just need a box of bearings, even used ones should work.
 
I did a 318 rods, rear seal and all through the pan and it came out nice.
A bit of a tedious job making sure not to mar the journals taking the upper halves out, but a little patience and some gentle persuasion it's not horrible.

A person does have to wonder what the cam bearings look like and those affect oil pressure also.
 
TrailBeast said:
I did a 318 rods, rear seal and all through the pan and it came out nice.
A bit of a tedious job making sure not to mar the journals taking the upper halves out, but a little patience and some gentle persuasion it's not horrible.

A person does have to wonder what the cam bearings look like and those affect oil pressure also.
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I agree. I'm going to pull the engine and see where things go from there.
 
GlennB4u said:
I seem to have an oil pressure problem after getting the engine to operating temperature. I've done a little reading and things point to worn bearings... main, rod and cam. I thought I'd pull my pan and take a look. I have no idea how the engine was taken care of before I got it, but the pan had a 1/2 inch of sludge in it, even after I cleaned it a few months ago...so that concerns me. The main bearing is pretty worn for sure. Does anyone see that this crank will need turned at all or can I save it?View attachment 1715044763 View attachment 1715044764View attachment 1715044765
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I would pull the crank and inspect it. Also, from your photo the oil hole for the main bearing is in the bearing cap. Not sure what brand main bearings you have but oil hole should be in the block. 65'
 
Plymouth 65 said:
I would pull the crank and inspect it. Also, from your photo the oil hole for the main bearing is in the bearing cap. Not sure what brand main bearings you have but oil hole should be in the block. 65'
Click to expand...

It could have both I guess, but if it doesn't I don't see that bearing living at all let alone from whenever it was done until now.
 
Plymouth 65 said:
I would pull the crank and inspect it. Also, from your photo the oil hole for the main bearing is in the bearing cap. Not sure what brand main bearings you have but oil hole should be in the block. 65'
Click to expand...


Some of the full groove main bearing sets just had upper bearings in the box. The hole in the bottom bearing is a common thing.
 
considering the sludge you said was in the pan, the block, crank and rods look pretty clean. I've seen much, much worse.
 
Cam bearing seldom wear very much... Doing a in frame overhaul without pulling the engine was the way it was done for 80 years... Still is with class 8 trucks. We used to bore a cylinder in a straight six and grind a rod journal while the engine was in the car...
 
Krooser said:
Cam bearing seldom wear very much... Doing a in frame overhaul without pulling the engine was the way it was done for 80 years... Still is with class 8 trucks. We used to bore a cylinder in a straight six and grind a rod journal while the engine was in the car...
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Whoa.
 
Krooser said:
Cam bearing seldom wear very much... Doing a in frame overhaul without pulling the engine was the way it was done for 80 years... Still is with class 8 trucks. We used to bore a cylinder in a straight six and grind a rod journal while the engine was in the car...
Click to expand...
that's the second time I've heard that. A guy I used to know told me similar stories. He said, they had a machine that clamped on to the journal, and they would roll the crank around a certain number of times, and it would take off so many thousandths of material. I didn't know if he was BS'g me or not. He could spin some yarns, that much I knew.
 
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