Micro Welding of bearing shell to rod housing bore

[CMcAllister]

Strange.

So there is no indication of an oiling problem? i.e. crank to bearing face contact/damage?
Or bearing shell being hammered (detonation)?

Any indication of the caps moving on the rod (fretting on the cap/rod contact surface?

Fretting/welding indicates parts are moving under load. Initial thought would be to tighten (decrease) the bore size to the minimum to increase the crush.

All I got. Will be watching for responses.

[Larry Hill]

The caps have dowels and the mating surface looks perfect. The upper shell is always not as tight as the cap shell in its bore.

Is there a certain finish that the bore needs to “hold” the bearings?

[Rich Biebel]

I've been reading this thread and wondered why no one mentioned detonation as being a possible issue.

It can show up in rod bearings....

Usually the shells just fall out....and might have some odd looking wear marks....

[CMcAllister]

Originally Posted by Rich Biebel

I've been reading this thread and wondered why no one mentioned detonation as being a possible issue.

It can show up in rod bearings....

Usually the shells just fall out....and might have some odd looking wear marks....

If the problem didn't exist, and now it does, something happened. I've seen upper bearing shells beat up to the point they just fall out of the rod.

Fly poop on spark plugs? Fuel change? Verify timing and TDC marks? Try another known good timing light?

Just reaching here.

[Billy Nees]

Originally Posted by CMcAllister

Fly poop on spark plugs? Fuel change? Verify timing and TDC marks? Try another known good timing light?

Just reaching here.

or cam change too!

[Larry Hill]

First noticed it when we started getting close to the 590 hp number. Damper is on TDC, fuel seems to make no difference c11, c12, c10, renegade 116. cam changed made no difference.

[Rich Biebel]

If the engine is apart and obviously it is....

Look at the ring lands and the tops of the pistons for any oddball signs that usually indicate detonation. Pecker tracks on pistons, or on the sides of the pistons above the rings. Ring lands beat up....

If all is clean then you can rule it out....

It's not likely but I thought I'd throw it out there.