joshcornett

i had a conecting rod bearing go out after bad over heat i replaced all conecting rod bearings and yes i miced the crank aprox 240 miles after the #1cylander bearing went again im thinking conecting rod strechedhere is pic of bearing where and cap the cap was clean when reistall

JamromXJ

Could be a stretched C-rod, or possibly a lubrication issue. I realize you installed new caps, but make sure the oil ports are not clogged around that are of the crank shaft.


Any idea how good the oil pump/pressure is?

RTorrez1

That was the first thing that came to mind for me.

Hog Rush

If you did not hone the rod journals on the rods to spec they most likely are egg shaped. More so after cap replacements. The rod bolts are also most likely fatigued and stretched too.

Bearings most likely were squeezed a bit after you torqued them down and when it heated up closed the tolerances even more.

Edited to add:
Serious engine builders will install the rod bearings in the rods without being in the engine. Then torque to spec and take measurements of the internal diameter of the bearings under torque. This is just another safety measure to ensure tolerances were held in the machine shop.

Expect a lot of bad stuff once things get hot in an engine.

bigbadon

1. Did you install the original size insert?
2. Did you check new bearing with plastigage?
3. Did you torque rod bolts to correct specs?

If yes to all 3 your connecting rod is probably egg shaped. You need to verify with bore gage. I doubt it is oil pressure or you would have heard noises on the top end. Theoretically you don't need pressure to lube rod bearings...if you have enough pressure to fill the lifter oil gallery, gravity in itself will deliver oil to the crank.