Re: Micro Welding of bearing shell to rod housing bore
 

The welding on my 440 stocker engine is on the piston side of the rod. If the rod parting line would be 3 o’clock and 9 o’clock with 6 o’clock on the piston side. The most of the transfer of metal is between 3:30 and 4:30 on one side and between 8:30 and 7:30 on the other side, with very little if any at the 6:00 o’clock position. Rod and piston approx 1750 grams.

Re: Micro Welding of bearing shell to rod housing bore
 

The bearing has a thickness specification that can help you determine the amount of crush you are getting after you torque the rod. How many use cycles do you have on the bolts and what type of bolt are you using?

Re: Micro Welding of bearing shell to rod housing bore
 

OK, I have no personal experience with this problem. But have talked with someone who I believe had a similar problem. He modified his rod bearings to give a little more clearance in just that area and that seemed to fix his problem.

Stan

Re: Micro Welding of bearing shell to rod housing bore
 

I have never had this problem. A long shot. Do you have your negative cable attached directly to the block? Ray

Re: Micro Welding of bearing shell to rod housing bore
 

Yes Ray the cable is connected to the block. I never considered an arcing or plating situation
Not sure on cycles on rods or bolts. Bolts are ARP 7/16 20NF 12 point. The big end of the rod stays rounder longer since we installed a clean neutral valve body in the trans. I use the brakes to stop the car without compression braking.

Re: Micro Welding of bearing shell to rod housing bore
 

Larry,
The design of the bearing is important. The size of the rod bore determines crush. You may need a bearing with more ellipse or a slightly thicker oil for the .003 clearance.
It is a long read, but Mahle has a good read on bearings.
All bearings are not created equal!
https://www.speedperf6rmanc3.com/con...20Bearings.pdf

Re: Micro Welding of bearing shell to rod housing bore
 

Thanks. I will read it

Re: Micro Welding of bearing shell to rod housing bore
 

Which Manley rod and which arp bolt ?

Re: Micro Welding of bearing shell to rod housing bore
 

Glenn I cant find the info on bolts or rods. Bolt stretch is .0055.

I need to finish my engine to race BG this weekend so my response time will be long until we are at BG.

Thanks everyone for the help and input.

Re: Micro Welding of bearing shell to rod housing bore
 

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.