Re:XR1000/Sportster conversion 3 Years, 8 Months ago
I investigated this option about 10 years ago. As far as I remember the major problem was that the hole pattern of the cyclinder studs in the XR heads didn't match the hole pattern in the crankcase of the newer Evo-Sportster. I even made a CAD drawing overlaying both hole patterns, but I couldn't find it in all my PC backups... bad housekeeping, sorry.
Re:XR1000/Sportster conversion 3 Years, 3 Months ago
Concerning the conversion of a XL Sportster engine into an XR1000 engine I found the following promising info in a another forum.
QUOTE: There are repo XR1000 cylinder studs for sale on http://www.ebay.com. Precision Grinding makes aluminum XR 1000 cylinders. Darcy Racing sells new "D" port heads and manifolds. Zippers will grind you a cam if John Steel doesn't have one. Fill the stock base holes on an 83 or later ironhead motor with threaded aluminum stock. Drill and tap the cases for the xr studs(7/16" nc using the XR square hole pattern) use S&S Evo Sportster rods (1/2" shorter)and you can make a better(and stronger) motor than Harley did for far less. F&S Harley has J&E pistons. They seem to have bought up all the XR1000 stuff that they could find. You can use a 1989 0r 1990 evo sportster drivetrain with the alternator and it already is a "C" ratio trans. Plus the chain case looks good too.....
Send me your email and I will show you my XR1000 motor. I have built three of these so far.