RE: Welcome to Club SAITO !
Bruce:
Sorry, I misread your last post. You did indeed sway crank CASE, not shaft.
That may be limited to the smaller Saitos, just checked a 72, n 91, and a 100 that I have down at the moment, none of them have the hole. It’s also possible that added drilling has been eliminated in later production. I don’t recall ever having seen it.
If it’s convenient, look at the forward end of the hole. Is it possible that it uses the swirling generated by the rotation of the cam to make a sort of centrifugal pump to make the oil circulate through the rear bearing and then through that hole back to the rear part of the crank case? Angling the hole off to the right as it goes forward would be an indication that they had this in mind. Or maybe a little ridge to the left of the hole in the cam chest. Excuse me, reverse the direction and side for the ridge, the hole would have to be under the cam.
Let me know your thoughts.
Bill.