Post #6 - Rotating Assy & Pistons

Recall that 60mph wicked vibration my Dad noticed - turns out the retaining nut of the sprocket shaft had loosened allowing about 0.25" play in loose the uninstalled state (I'm sure with the bearings support & such, the assembled movement wasn't that much). This looseness translated into a bit of con rod slop & abnormal pinion shaft wear - but that's about as far as I can see the damage went. I'm not totally certain - but fairly confident the 60mph vibration is directly related.

Pistons:
The original pistons (at least they appeared fairly original, cast iron bits) had some fairly good skirt scuffing, other than that - they were in good shape. Seeing that I bored 0.010" over, I needed new pistons anyway so I didn't do much investigation into piston health & just ordered some forged aluminum hardware from Wiseco.

Con Rods:
The Pan's con rods appeared to be square (no bends) & only had some abnormal wrist pin bushing wear due to the odd alignment (more sprocket shaft induced fun). The large end bearing races looked smooth (no pitting) - so I only replaced the wrist pin bushings. A bit of a knick in the middle of the front cylinder's rod didn't cause much concern for me, but both my dad & the Boar House weren't fans. Add that to the fact that the bore house pointed out my crappy bushing install (a bit crooked - can't always rely on the con rod to guide the busing properly will provide some side loading of the wrist pin & eventually drive past the pin keepers & into the cylinder bore...) & the con rods were junk. I got some new, replica rods from V-Twin w/ the bushings already installed & races hones to fit a matching crank-pin & bearing setup.

Pins & Shafts:
The Pan's crank pin had some surface pitting, likely below the hardened surface - so that was immediately junk. Replaced - as mentioned earlier - with a V-Twin replica.

The Pan's pinion shaft developed some abnormal wear @ the very end (bit that's riding in a bushing within the gear case cover). Instead of actually wearing the brass bushing - the shaft wore quite significantly. So that was junk as well - replaced with a V-Twin replica. This new shaft fits well inside the original gear case cover busing - so I kept that bushing.

The sprocket shaft was worn & pitted on the taper mating surface due to the looseness.... junk as well - replaced with a V-Twin replica.

I thought that'd be the end of replacing this rotating parts - I mean - there's not much left...

Flywheels:
The flywheels appeared to be original hardware. Even though the sprocket shaft worked loose - abnormal wear didn't appear present in the taper joint - so I thought they'd be reusable. Turns out - they weren't. Knowing that I was going to be changing quite a bit of cranking assy stuff - I brought all the new stuff in for static balancing @ the Boar House. They educated me to look for the signs of an abused flywheel assy - & the weld build up & peening of the con rod thrust washers was a good sign that these flywheels had been apart a number of times. I'm not sure who did this work (likely the dude because I pretty sure my dad's chicken coop didn't have a welder..) but it was awesome. The Boar House gave reuse a go & ended up breaking chunks of flywheel off with every attempt to peen new washers in place; I trust they were honest with their attempts & not trying to take advantage of my naive ways. Eventually - I landed a set of Truett & Osborne flywheels (stock stroke) in a complete assy from V-Twin. They managed to balance the everything (they should've been able to - everything was spankin new..).

Pinion & Sprocket Shaft Bearings, Washers & Oil Seals:
The shaft bearings measures to stock diameter but fit a bit loose. The races measured round & true. Combining the two measurements - I found, with some light honing, that I could get a real good fit with +0.008 bearings for both the pinion & sprocket. My dad & I pin-honed these bores and, although not mirror finish, the fit is great. I reused the original bearing cages.

The crankshaft thrust washers were a bit pitted but cleaned up & are also being reused.

I installed a new sprocket shaft oil seal. The oil ring for the pinion shaft - although I recall seeing it sometime during the disassembly - has caught the Santa Anna winds & fled - so I've got to find one of those.

I noted there was a bit more side - to - side play in the sprocket shaft bearing - to - oil seal area, so I found a thin washer to take up some of that side play. The washer has a bit of a crap on it that I couldn't clean off (it's uber thin & I didn't want to distort is permanently). I'm trusting a bit of running will smooth that washer out...
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So I haven't touched on a few parts of the engine tear down yet (gear case, cases...) - I'm getting there - but I'll tell you something about the new parts in their installed state as of today. I thought I had all of the i's dotted & t's crossed when it came to the rotating assembly. Maybe after reading this posting you can already point out where I've fucked up.... think about it a bit...

I didn't check the thrust clearance of the crank assy with respect to the case races. I did some preliminary installs & threw a couple of case studs in to make sure things were ok & during pin honing of the case races - I thought it was going to be a snug but OK fit. During my final install of the rotating assy into the cases - with everything pre-lubed, that gunky washer installed, & the case studs torqued to spec - I found things real snug. I could still force rotation by hand (pushing on a con rod or something - not by grabbing the sprocket shaft though - that took a wrench)....

Understand that I try to do these technical tasks always in a time crunch for 1000's of reasons & my patience with the engine at this stage was thin so I charged on thinking - maybe that gunky washer or the prelube is causing that drag. It's been 1 month since I did that engine assembly. Before I try to start this beast - I'm gonna tear this whole engine down again & mill some race material away to free the rotation a bit. Maybe I'm being too sensitive to this, maybe there's a better solution - but the cases are the only identification the Pan retains & with respect to thermal expansion - I don't want to end up pushing races out or cracking the cases - so better safe than sorry.