ConcoursMustang Forums

Restoring - General discussions that span across many different groups of years and models => Drivetrain => Topic started by: CW4macret on September 06, 2024, 12:07:59 PM

Title: Help!!! Number 5 rod bearing spin.
Post by: CW4macret on September 06, 2024, 12:07:59 PM
I have a K code block I got disassembled. My engine builder went through it and rebuilt the engine. While on the test stand it spun the number 5 rod bearing. Engine has great oil pressure. When disassembled and inspected all other bearing surfaces looked great. Replaced the crank and rod bearings. Put on test stand and once again spun the number 5 rod bearing. All other bearings look great,  Replaced the rods, 3rd crank and all the crank and rod bearings. Put on test stand and spun the number 5 rod bearing again. Any ideas?
Title: Re: Help!!! Number 5 rod bearing spin.
Post by: KenFirch on September 07, 2024, 07:26:05 PM
Man!  That's got to be frustrating.  Maybe the #5 bore axis isn't square with the crank axis?  I'm not even sure if that's possible with modern CNC boring machines.
Title: Re: Help!!! Number 5 rod bearing spin.
Post by: Bossbill on September 16, 2024, 02:29:44 PM
I like Ken's idea.

Can you put the block in a honing machine (or?) with a dial indicator on it and go up and down with the spindle? Fore, aft, right, left  with the indicator to indicate anything out of axis?

I'm not a machinist, but you get the idea.
Title: Re: Help!!! Number 5 rod bearing spin.
Post by: CW4macret on January 22, 2025, 04:04:22 PM
Turns out Ken was correct. Had to take it to a different machine shop but that's what he found.
Thank you all.