"The rotation issue is pretty
"The rotation issue is pretty clear in my mind, you can call it whatever you want until you get to the machine shop and then you better darn well know. In a twin engine config, you "always" have a RH prop rotation on the right side of the boat (starboard) and a LH rotation on the left side (Port).
The concept of using the flywheel side of the motor to make the determination is dangerous when you get to the Chris Craft "flywheel forward" motors.
I have two SBC marine motors and four big block Ford 427s. Of the two small Chevy motors, one (in my 1956 17' Chris Sportsman) is a flywheel forward installation, but the motor is actually turned around backwards with the front of the motor bolted to the transmission. This is a standard LH automotive rotation but the prop is a RH rotation. Take this motor in for a rebuild and tell them it's an opposite hand motor and you'll have a real mess. The other SBC is flywheel aft and it also has a RH prop rotation, and it is a true opposite rotation motor in every sense of the word.
Now get to the SBC motors Chris Craft called the "Q" designation, those are mounted with the motor facing forward just like a car, but the flywheel is actually bolted to the front of the motor. This is something I, personally, was really not aware of until recently, and I thought the posting I referenced would help someone like me understand this better. Anyone looking at the flywheel on one of those motors and trying to figure out the rotation is going to be in trouble, right? Reason: the port Q motor on a twin flywheel forward installation, is going to be a true RH opposite rotation motor, and looking at the flywheel it will suggest (to the uninformed) that it is a LH motor because it's spinning left when viewing the motor from the flywheel.
You got it! Darn confusing! I'm still at a loss, as are many, why in the heck some of this was done.
Anyway, this is a great forum here, a great reference, I have referenced numerous people here and it's worth it's weight in gold bullion.
Regards,
Paul"