Scored Main Cap Bearing - Ouch

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I have done this on a different engine......put in diesel and pumped it through the engine with a priming rod, while turning the engine over slowly by hand. Drained the diesel a couple of times. This was to clean out the mains and rods. Then pulled lifters one at a time, starting closest to the pump, while priming, to clean out the lifter bores with diesel. In this engine, you'd then have to clean out the rockers shafts and heads. I then pumped cheap oil through with a coupla changes while turning over slowly times to clear the diesel out. Then put in the oil I wanted and changed it after 5 minutes running, and once again after 10 minutes.

It was an engine I did not care a ton about, and was done to get coolant out; did well for that, but IDK on metal particles.

How about a pix of the #8 rod bearing and journal please?

Inspect the oil pump if it was new at rebuild. If it was new and you see a lot of scoring and chewed tips of teeth, etc., then you know metal particles were pulled out of the pan. The pump is before the filter. (If it was not replaced at the rebuild, then inspecting it won't tell you anything.)
 
Exactly, A little money for bearings, seal, and I already have pan gasket. If I dont find any further damage I am going to try it. Any ideas on how to flush.
 
nm9stheham said:
I have done this on a different engine......put in diesel and pumped it through the engine with a priming rod, while turning the engine over slowly by hand. Drained the diesel a couple of times. This was to clean out the mains and rods. Then pulled lifters one at a time, starting closest to the pump, while priming, to clean out the lifter bores with diesel. In this engine, you'd then have to clean out the rockers shafts and heads. I then pumped cheap oil through with a coupla changes while turning over slowly times to clear the diesel out. Then put in the oil I wanted and changed it after 5 minutes running, and once again after 10 minutes.

It was an engine I did not care a ton about, and was done to get coolant out; did well for that, but IDK on metal particles.

How about a pix of the #8 rod bearing and journal please?

Inspect the oil pump if it was new at rebuild. If it was new and you see a lot of scoring and chewed tips of teeth, etc., then you know metal particles were pulled out of the pan. The pump is before the filter. (If it was not replaced at the rebuild, then inspecting it won't tell you anything.)
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I actually put a new pump in when I pulled the pan the last time. It was hitting a corner of the Miloden pan and I didnt like it. The other pump was older hi volume. I used a stock pump and gained extra clearance and only lost about 5 pounds. Mtr still holds 40psi hot (180) at idle and 65 on hwy with 10/30. For the repair I bought Comp Cams break in oil for first few hundred miles once I decide on flushing. My oil filter and pump tear down will determine that.

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blewbyoutobad said:
I actually put a new pump in when I pulled the pan the last time. It was hitting a corner of the Miloden pan and I didnt like it. The other pump was older hi volume. I used a stock pump and gained extra clearance and only lost about 5 pounds. Mtr still holds 40psi hot (180) at idle and 65 on hwy with 10/30. For the repair I bought Comp Cams break in oil for first few hundred miles once I decide on flushing. My oil filter and pump tear down will determine that.

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Judging by the pic of that bearing you have something else going on other than pressure issues.
It appears to be the old chicken or the egg theory, which came first.
Did trash tear up the bearing or did the bearing create the trash?
 
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512Stroker said:
Judging by the pic of that bearing you have something else going on other the pressure issues.
It appears to be the old chicken or the egg theory, which came first.
Did trash tear up the bearing or did the bearing create the trash?
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I am hoping more tear down discloses more secrets to the problem.
 
Rod bearing looks pretty bad for 400-500 street miles... Looks like an abrasive went through there. What brand of bearing is that?

So the other rod bearings don't look like that at all?

Gotta wonder if a bunch of trash was left in the vertical oil passage between the #5 main and #5 cam bearing?

BTW.... we're all have a 'duh' moment LOL. The pan is off... examine that to see what is in the bottom!

The oil pressure numbers sound pretty good.
 
nm9stheham said:
Rod bearing looks pretty bad for 400-500 street miles... Looks like an abrasive went through there. What brand of bearing is that?

So the other rod bearings don't look like that at all?

Gotta wonder if a bunch of trash was left in the vertical oil passage between the #5 main and #5 cam bearing?

BTW.... we're all have a 'duh' moment LOL. The pan is off... examine that to see what is in the bottom!

The oil pressure numbers sound pretty good.
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Should have the other rod bearings inspected this afternoon.
 
blewbyoutobad said:
I actually put a new pump in when I pulled the pan the last time. It was hitting a corner of the Miloden pan and I didnt like it. The other pump was older hi volume. I used a stock pump and gained extra clearance and only lost about 5 pounds. Mtr still holds 40psi hot (180) at idle and 65 on hwy with 10/30. For the repair I bought Comp Cams break in oil for first few hundred miles once I decide on flushing. My oil filter and pump tear down will determine that.

View attachment 1715483932
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That rod bearing got hot, and probably from a lack of oil.
IMO you might have some wild variances in the clearances of your rod and main bearings allowing good oil flow on some bearings and not much on others.

I would put some serious thought into making them rebuild that motor again.
Or even making them fork over for a different shop to do it.
Obviously the shop that did it has shortcomings in the engine building department that would make me never trust an engine they did.
I'd be afraid to go anywhere in the car that I couldn't afford the tow bill to get it home.

I don't like to put it this way, but it's the way it is.
They have your money and you have a disaster.
Sound like a fair trade to you?
 
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As I stated before, check the thrust main side surfaces on the CRANKSHAFT. They should be flat without any grooves. A new thrust main with the correct undersize can be slid over the crank and then check the end play with a feeler gauge.

The one sided wear of the bearing could be from the crank being pushed out of position. I haven't seen any signs of a spun bearing.
 
blewbyoutobad said:
yes, the crank is scored. ,Yes a reputable shop did the work. Has to be junk left from the rebuild. not much sense in going any further.
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All trash has probably gone I to the filter at this point. If the cam bearings arent destroyed...you could just re bearing it, polish the crank and run it...save the under sizing for the next rebuild.

you only have so many rebuilds on an engine block and so when it goes down like this it's really disheartening cuz if you cant fix what you got... you have to use up a life , so to speak ...and go the next undersize and over bore...and spend 800.00 for pistons, rings, bearings, gaskets...oil pump.

Do not use that same oil pump again.
You can inspect it, but I'm sure the impeller cog is scored.
 
Tore pump down and it looked brand new. No scoring or marks anywhere. Confirms my thought that all this happened on start up. This pump has about 50 miles on it. Next is the oil filter inspection which was changed the same time the new pump was put in.
 
512Stroker said:
I lost something here.
You changed the oil pump when you changed the filter on a fresh engine? I am lost.
Is this the second oil pump on this build? If so why?
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Bout 50 miles or so before the dropping of the pan this time round to do the rear main seal. Before he was just changing pan gaskets to no avail. He had a leak, that's what started this. Or at least how I understand him.
 
I've been trying to follow all of this, forgive me if I missed something or it was already discussed. With the original problem of the rear main oil leak and now all the issues with the bearings, I think he might be better off starting with a new crank? Is this the only machine shop you have around you? It may be less hassle just to get a reman crank from summit, advance auto, or something than continue to deal with that shop... he can pull it apart, clean the snot out of the block, reassemble and not have to ever talk to them.
Just a thought
 
The crank for sure needs addressed. I don’t want to reread everything but I think he said the crank was knearded in the rear main seal area. That was an old school trick to help seal old rope type seals that were undersized.
 
gliderider06 said:
I've been trying to follow all of this, forgive me if I missed something or it was already discussed. With the original problem of the rear main oil leak and now all the issues with the bearings, I think he might be better off starting with a new crank? Is this the only machine shop you have around you? It may be less hassle just to get a reman crank from summit, advance auto, or something than continue to deal with that shop... he can pull it apart, clean the snot out of the block, reassemble and not have to ever talk to them.
Just a thought
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It all started with a rear seal leak. I tore it down and found scored main bearings. Journal looks pretty good after cleanup. Then I found where the bolts for the flywheel were wrong and groved the main cap and ground them off. So I started looking at rod bearings and will look at more today. I dont think the crank had a good chamfer on the rear main. #8 rod was gone and #7 looked pretty good. The thrust bearing is bad. So today now that I have time I will pull other main caps and look at them and rod bearings to see if these are the only ones or are others like it. The mtr has had one oil change about 50 miles ago, 4-500 total.
The mtr is still in the car and pulling it is a big pain since I am 66, but in good health. I also live in the country and dont have any friends that can help. So its basically just me. I can find probably find a couple of people to help but they have not worked on cars before. So I was talking to Pittsburg Racer about this and it was decided the motr needs to come out. Probably new crank, line bore etc since this one is damaged and unknown. So I'll start looking for some help to pull the tranny and mtr.
 
blewbyoutobad said:
Tore pump down and it looked brand new. No scoring or marks anywhere. Confirms my thought that all this happened on start up. This pump has about 50 miles on it. Next is the oil filter inspection which was changed the same time the new pump was put in.
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Ah OK. So we won't learn as much as hoped from the filter and pump inspection about what was and went where, except that there was not a lot of metal in the engine. If the prior filter was around, that would be more useful. OP did you find much in the way of metal particles in the pan when you pulled it this time or last?

Ooops never mind!
 
nm9stheham said:
Ah OK. So we won't learn as much as hoped from the filter and pump inspection about what was and went where, except that there was not a lot of metal in the engine. If the prior filter was around, that would be more useful. OP did you find much in the way of metal particles in the pan when you pulled it this time or last?

Ooops never mind!
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I hope to get to the filter and pan inspection today and the rest of the mains and rod bearings.
 
Update, rod journals on 7/8 have been cleaned up with 400/600/1000. Journal on 3/4 looks good. It appears when they turned the crank they left sharp edges around the chamfer hole from the previous chamfers. You will see in some of the bearings a line where the chamfer hole is. I polished the edges of holes with 600 and 1000 and my finger like a debur tool. They are smooth now. The thrust bearing surfaces look good, no scoring. I am ready to pull 5/4 and 1/2 rods and take a look at them. If the filter and bottom of pan check out ok what do you think about putting new bearings and a seal and run it. At 50/100 miles pull the pan and see what it looks like. I already have the bearings and a spare mtr with forged pistons if this doesnt work out. Think its worth a try? For me a lot better than pulling the mtr. The really scored bearings are 7/8 and the rear main. The other rod bearings are 3/4. Journals are main #1, thrust, 7/8 rod and rear main. In case you are wondering here's what I am working on. I used some long Q-Tips and gently checked the oiling holes and they were clean.

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You made me run down to my shop to see something. In that I think its the fifth picture down where you can see that 9/16 oil plug. Its hard to tell from pictures but man it doesn't look like that plug is installed deep enough. Please double check that because if it isn't seated past the oil filter outflow hole that's a major issue. I'm not sure what the measurement is from the bottom but its approximately 7 9/16 from the top deck surface.
 
pittsburghracer said:
You made me run down to my shop to see something. In that I think its the fifth picture down where you can see that 9/16 oil plug. Its hard to tell from pictures but man it doesn't look like that plug is installed deep enough. Please double check that because if it isn't seated past the oil filter outflow hole that's a major issue. I'm not sure what the measurement is from the bottom but its approximately 7 9/16 from the top deck surface.
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I missed that, but you are right.
That would totally screw with the oil flow, and could even explain that one burned rod bearing posted earlier.
 
pittsburghracer said:
that 9/16 oil plug. Its hard to tell from pictures but man it doesn't look like that plug is installed deep enough. .
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I see it too, it doesn't look deep enough, just measured a 360 for a reference, to the plug edge (not the dish) i get 2.045 inch from block main area.
 
Max1196 said:
I see it too, it doesn't look deep enough, just measured a 360 for a reference, to the plug edge (not the dish) i get 2.045 inch from block main area.
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I never measured from the bottom but I will write this figure down in my notes. Thanks.
 
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Got this from Moparts.

A press-in plug goes into this oil passage at the rear of the block. The plug is about 21⁄8 to 25⁄16 inches up from the bottom of the block (without the cap) and 71⁄2 to 711⁄16 inches down from the china wall. The plug forces oil from the oil pump to the oil fi lter and then to the main oil galley.

(2 and one eighth to 2 and 5 sixteenths from the cap mounting surface)
 
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