Micro Welding of bearing shell to rod housing bore
 

Any ideas ?
Could it be when the combustion occurs the bearings take a hit in the middle causing the outer parts of the shell to move away from the housing just slightly and then return causing a fretting action and transfer of metal, from shell to housing bore.

Re: Micro Welding of bearing shell to rod housing bore
 

Rods out of round or inadequate bearing crush. I'm just spit balling ideas.

Re: Micro Welding of bearing shell to rod housing bore
 

Bearing type/part number and rod type and application?
General answer: Fit in housing bore
Pictures?

Re: Micro Welding of bearing shell to rod housing bore
 

Manley rods, King not as bad as Clevite 77, housing bore round according to AG 300. No pictures all the evidence is gone, removed.

How is bearing crush measured and where can the specifications be found?

Oil is semi synthetic

Re: Micro Welding of bearing shell to rod housing bore
 

I don't know if it's correct or not, but I use a height gauge to measure each shell and to verify that the shells are square, which I've found some that are way off. I've had rods on the small end of spec as well as the big side both do it. :confused:

Re: Micro Welding of bearing shell to rod housing bore
 

using too thin of an oil ?---oil is not "thick" enough and not enough "pressure on the bearing" to keep the proper spacing between bearing and crank

Re: Micro Welding of bearing shell to rod housing bore
 

Larry,
Are you saying the Micro Welding is happening near the ends of the bearing?


Stan

Re: Micro Welding of bearing shell to rod housing bore
 

How much clearance are you running and what oil weight?

Race bearings usually have additional crush built in them. Are you using a torque wrench or a bolt stretch gauge values? Make sure the main bore is round and check the size without and with the bearing installed.

This is a method used to check crush.
https://lh3.googleusercontent.com/pr...cfIEn5dIZLriTg

Re: Micro Welding of bearing shell to rod housing bore
 

I have seen the microwelding almost 3/4 the length of the bearing, and probably 3/4 of the width on the most severe ones.

Re: Micro Welding of bearing shell to rod housing bore
 

2.375 crank pin, 5W30 oil, close to .003 vertical bearing clearance, bore is round within .0002, stretch gage.

I'm not understanding how to check housing bore diameter with the bearing installed.

Thanks