14-09-2020, 10:22 PM
(This post was last modified: 14-09-2020, 10:25 PM by Colin Wilks.)
Bob, I'm interested in your comment "Slight distortion occurs when the cap is tightend, esp if the caps not perfectly filed.", which would explain the different contact patterns I described. I have not really considered trying to improve the alignment of the rod and the cap as I'm not sure where I would start, and taking any material off the jointing surfaces will make the rod tighter on the journal. How would you go about working out which shoulder to reduce, or are you meaning just a debur and polish? I wondered if the rods were fouling the face perpendicular to the journal as I could get only a .006" feeler blade in. I bolted the rod and cap together and filed a total of about .010" off, so the outside babbitt faces are true to one another. I am still a long way from Woodrow's recommended maximum of about .060".
I am as confident as I can be that the rods and caps are correctly numbered and orientated, and have test fitted them all in different permutations, so I am starting from how the engine was before disassembly and from the best starting point.
The car has done less than 1,000 miles since a orofessional rebuild ten years ago. It had done only 350 when I got it. The babbitt in the tight rod had blurred across the joint as you describe and I reckoned I was lucky not to have run the bearing, so in fact the oil leak did me a favour!
I am as confident as I can be that the rods and caps are correctly numbered and orientated, and have test fitted them all in different permutations, so I am starting from how the engine was before disassembly and from the best starting point.
The car has done less than 1,000 miles since a orofessional rebuild ten years ago. It had done only 350 when I got it. The babbitt in the tight rod had blurred across the joint as you describe and I reckoned I was lucky not to have run the bearing, so in fact the oil leak did me a favour!