??? The Honda spec on the std pins is 14.994-15.0mm (.5903-.5906) and all the pins I've ever measured have been in that range, maybe a couple tenths wear in the middle. We just fit a set of the oversize pins last night. I built a fixture to hold the rod, and the machinist who did the pistons on his Sunnen actually made a house call and reamed the small ends for me with an adjustable reamer like you buy from McMaster-Carr. I would have done it myself, but I was chicken and he hadn't seen a 305 in person for a long time... Anyway, it was no big deal, the holes came out to 5-tenths clearance true within a tenth or so all the way across and the pins feel perfect in there. You're really not taking much off, and with a light touch and some patience the reamer follows the hole very well. Took about 10 passes to dial it in. Anyone who wants to borrow the fixture is welcome to it for the cost of a small flat-rate box. I started a thread on the oversize pins a while ago, I'll pop that post with a picture. Got "reamed" pretty good as I remember for not pressing the crank apart and doing it "right." We'll hold judgement though for 1000 miles or so.
-48:)
piston pin small end rod clearance cl77 305
Sorry, I misread my mic. I measured about 10 NOS pins and they were all .5905"or 15.00mm.
How did the finish come out with just the reamer? or did you also do a final hone ? Tim
Hey no apology necessary! Came out smooth, almost like a honed surface. The last few passes were done with only a very slight tightening, if any, of the reamer. You could run a ball hone through them, but that might bellmouth them a little. I think they're good as-is. Here's a picture of the fixture to hold the rods. We tipped the engine forward to rest on the starter flats, so no chips went into the crankcase.
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