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Engine bearing pics and questions

garlicbreath

garlicbreath

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SO I pulled my motor due to wierd noises. Here are some pics of the 2,3 4 crank bearing and #4 rod bearing caps. You can see copper in the mains and the rod bearing isn't worn in the middle, only the sides. So to you guys who build or have built engines, what causes this? I had the motor rebuilt 4 years ago, but it only has 1000 or 2000 miles on it. Should I pull the motor apart and drop it off for machining or just throw new bearings in it? What have you guys paid for going through a short block?

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I hate bumping my own threads but I need to get this figured out by Monday morning. Anyone?
 
My guess is that the rod bearing in the rod itself has copper showing. If that is the case then you have detonation which caused this damage and you need to repair the engine then fix the reason why it is detonating. Detonation will make the main bearings in the caps copper and the rod bearings in the rod itself copper but the main bearings in the block will be fine and also the rod bearings in the cap itself will be fine.
 
Another thing that can cause that kind of wear on both Main and rods is a bent or distorted crank. Have your crankshaft checked.
How are the upper 1/2 rod bearings? Detnoation shows up more as wear on the upper rod bearings. The lower half usually dont show as much wear.
It would be better if you had pic of all the bearings in order to make a diagnosis.
But if some of your bearings are worn and some look good. I would suspect a bad crank or a misaligned block
 
I pulled most of the motor apart today. The front and rear mains were fine, no copper. I pulled a head and besides lots of soot everything seems ok. I haven't pulled a piston but might tomorrow since it does make sense that the bearing in the rod and the bearing in the main cap would show the wear from the downward forces. There is virtually no cylinder wear, you can still see the cross hatching.
 
One thing I did noticed that was disturbing was a deep worn grove in the timing cover from the cam gear bolts. It is a factory roller motor so it has the bolt in retaining plate, but it harkens back to when I had it rebuilt by Verle Stevens Enterprises in denver on colfax. I put the motor in after they did it and it was knocking from the timing cover real bad. My situation dictated me leaving it alone for a year since I moved to NY the next week. I came back a year later, pulled the motor and dropped it off to them to fix it. I am thinking they forgot to install that retaining plate. Could those bolts rubbing into the timing cover and the resulting metal shavings have ruined the bearings?
 
Looking at the pics. There is a little wear from dirt/metal shavings but its not that bad. The problem is the wear down to the copper. The wear on the bottom half of the bearings tells me it is not just a detnotaion problem. The major wear was not done by particles in the oil.
With the few miles on that engine. There is definatly a problem with your crank and or block algnment and who knows what else with the cam gear hitting the timing cover. IMHO. You should to take the block, crank, and rods to a machine shop and have them all checked out. With all your problems with that engine who knows? Someone might have droped the crank or something. could have a bent or twisted rod or the block is out of align and needs line bored.
 
i would like said get the crank checked for run out and bent. but also have the block checked with the mains on it to see if the block needs line bore done.
 
You should have zero runout on the crank main bearing surfaces, bolt the front and rear caps in it (no rods of course) and check runout if you've got the tools. Pretty easy to do yourself.
 
I am a machinist so I have the tools. Keep the ideas coming, I will check the crank this week for runout.
 
I know a few people will know how its done. Machine shops can and do check this, but I imagine its a bit more precise than using a dial indicator lol. :)
 
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