This time a link to a very exciting project, some Italian guys are building a 500cc V4 two stroke engine from scratch!! They are going to use as much of the shelf parts as possible, like Gokart or Honda RS125 barrels an MV Agusta cassette gearbox, a Ducati 1098 dry clutch, a zeeltronic ignition unit, Dell Orto carbs and home made cranks.
For more pics and information (in Italian) see
V4 500 two stroke project