No, the two crankshafts have to be welded together. Then Keith from BME also recommended that the original, factory pressed together joints of the crankshaft be pinned as well. They had problems with the crankshafts sometimes twisting at the pressed together joints and getting out of whack. I think one of the people that built one of the twins had the same problem.

What you have to do is drill a hole through the crank throws and rod journals where the crank is pressed together, and drive in a drift pin. Be sure that the holes and their pins are 90 degrees to the direction of rotation so that centrifugal force does not try to throw the pins out. I would also use some stud lock, or perhaps Loctite on the pins when installing them.

You might browse through the thread on the twin, as I vaguely remember that someone posted some pics of doing the process.

AV8TOR