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Rod bearing look smashed?

2K views 5 replies 5 participants last post by  vinniekq2 
#1 ·
What causes rod bearing to wear out or look smashed? They didn't spin, but all the rods have wobble on the crank. I don't see heat discoloration on the crank journals, though they are a little scratched from dirt or debris.

In this case it's on a 402 bbc

I haven't checked the mains yet.
 
#3 ·
Pictures speak a thousand words, post some up.

Did this just happen with a new build or did you tear it down and find worn bearings? Are top and bottom inserts worn? Are they actually flat spots or just worn in one area? Did you have a vibration, like it was out of balance?

From your short description, sounds like excessive clearances beat the bearings, you should have heard them knocking.
 
#4 ·
Never heard the engine run, I can get pictures tomorrow. Just a tear down.

No flat spots just equally worn out all the way around, I can spin the crank a few degrees with no movement of the piston on some. But none are spun. Just worn to the copper.

The motor appears to have been rebuilt at one point, bearings are marked .010. But clearances at this point are unk.
 
#6 ·
spend a lot of time measuring the crank all over for flaws,out of round,out of square,too much clearance,out of balance,bent(steel). Nothing anyone here can do without seeing or measuring.
block could be out of square,high mileage or racing history,lack of oil changes,not clean,,,,
 
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