96" crank in 88 cases?

[neonhomer]

This question is a bit out there, but brought on by a quick flash of fear. A mechanic friend of mine is going to pull my primary cover this weekend and check the clutch and chain and compensator bolt/nut/whatever. I was thinking in my head how he would be going through all this, getting to the bolt, putting a torque wrench on it and thinking.... "If 160 ft/lbs gets loose, let's try 180/190/200/etc)..... SNAP!!! " Mental scene ends with him calling me telling me I need either a new crank, or a way to get the old bolt out. So I was thinking about eBay cranks, and thought about a 96" crank. Could you drop a 96" crank into a 88 case without too much fuss? I don't know what the bearing specs or sizes are, journal sizes, etc etc... so I can't figure it out. I am going to say no.... only because the MC made a few changes between the 88 & 96, that they probably used larger journals, larger bearings, more case clearing , etc etc...

[mentor70]

the crank will work, but the bearings may have to be changed.

if the 88 motor is newer than 03 it may interchange. if its older it will need Timken bearings
I would change to timkens regardless.

you will need new pistons to match the crank because the stroke is now longer.

if you buy a used crank, i would get it trued and welded before installation.

[Hillsidecycle.com]

You'll also need all the primary internals, ie, fine-spline.
Scott

[07RoadHawg]

To add to what Scott said, I'd imagine you might have issues with the primary chain alignment too since the chain is behind the starter ring gear (inboard toward the inner primary case) on the TC88 and it's in front of the starter ring gear (toward the outer primary case) on the TC96. If it required a new clutch pack from a TC96 setup, I don't know if the splines are the same on the trans input shaft. At the very least, the starter won't line up with the ring gear anymore and you would need a new inner and outer primary setup.

I suppose you could make it work, but (and this is just my opinion) I'd go for a stroker crank made for the TC88. Sure it might cost more up front, but considering all the work you would have to do to get the TC96 crank to work.... FWIW