Installing Squarecase cams in a Roundcase engine

The rockers and cams on my bike were both worn. Megacycle resurfaced the rockers for me, but at the time they weren't regrinding old Ducati cams and didn't have any plans to make any more billet cams for them. That left me looking for another set. Phil at Road and Race has reground 750 cams available, but I found some mint condition cams out of an 860 locally. (Thanks again Rich!)

It's possible to switch cams between squarecase and roundcase engines, but there is a catch - the key on a squarecase cam is cut 10 degrees off from where the roundcase keyway is cut, so you have to compensate for that when you assemble everything. I won' t go into the details of how to do this as the Ducati Owners Club Victoria has a great article on their website that covers it in depth. They've changed the website recently so my old link no longer orks, but if you go to the main page, click on articles, then search on "cam timing" you'll find them. It's a three part series on the "Mystic Art of Cam Timing".

If you read these articles, you'll get an idea of what's involved. In theory it not a big deal, in practice it's a little more troublesome. Some of the issues I ran across:

If you are using a degree wheel from Vee Two, beware of the markings! I spent a few minutes wondering how the heck I could be so far off on my measurements between the front and rear cylinders! 180 degrees off in fact. After a bit of troubleshooting I figured out the degree wheel is labeled incorrectly - the events are out of order. Ignore the TDC and BDC markings for the "other" cylinder and you'll be fine. (If you set it up using TDC on the front, the rear will be wrong, if you set it up on the rear cylinder, the front will be wrong)

No modifications were made to the heads. I replaced the valve guides and put in new valves. I also freshened up the seats, but there was no porting done.