I've written out a reply a few times for this post, but I think CA sums up my comments with less snark. (I do happen to know what a cam shaft looks like. It's all wobbly bobbly cammy stuff.

But it's just like replicating any other previously made item. Either get the original drawings for it and copy that, or find one in the real world and copy that one. Given that's a pretty popular engine, I'm sure there's a lot of user guides for that engine, as well as one available pretty cheaply in your local junk yard.