Posted by Matt Wilson [108.162.221.32] on Wednesday, October 04, 2017 at 19:44:07 :
Just got the various engine parts for my 265 flathead back from the machine shop. I noticed the piston pins fit into the commectimg rod bushings without needing to apply "thumb press fit" pressure, as called for in the rebuild manuals. Of course, some of those same manuals say the clearance between bushing and pin should be zero to 0.003", which is small clearance, but not anything that would be a "thumb press fit" unless maybe you have one right at zero clearance, but it doesn't seem like that would be desirable anyway.
I asked my machinist about it and he said the clearance was good on all of them. I will do my best to measure the diameters myself, so I can verify the clearances, but getting an accurate inside diameter measurement has always been a challenge for me.
Interestingly, he said he uses a machine that keys off the pin diameter (using two pins at one time) to achieve the bushing bore diameter, so he doesn't have to hone a little, then measure, then hone some more and measure again, etc.
I'd be interested in comments you guys may have on any of this.
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