I think that Jethro Tull was merely trying to determine if this is an internally or externally balanced engine. There are indeed some engines in the world that are balanced internally and then the flywheel and harmonic balancer are balanced individually. This is an internally balanced engine. In the case of an internally balanced engine, you can simply install a flywheel that is separately balanced and be okay.
The externally balanced engines are balanced by adding weight in the correct position on the flywheel/harmonic balancer while they are attached to the rotating assembly. Thus the flywheel is balanced for that particular engine and will throw any other engine out of balance. It will also throw the engine it was balanced on out of balanced if it is removed and reinstalled in a different position.
If indeed the engine he is working on is an internally balanced engine, he could simply exchange flywheels because they are all balanced off the engine.
I feel a little guilty here because I answered him in another thread regarding taking the flywheel from his original engine and bolting it to the engine that originally had an automatic. It never occurred to me to question whether or not this is an internal or external balanced engine. If it were mine, I would have put it together and never even thought twice about it.
The question that now needs to be answered is: Is the 616 engine internally or externally balanced.
I expect that Jethro has exchanged flywheels on some engines before with great success. Those would have been internally balanced engines.
BTW, I think that it was a little unfair to respond to Jethro's question by insinuating that the question was absurd. He is coming to everyone here asking a legitimate question. He was using some terms in his question as an exxageration, or sort of a joke. Since there ARE engines that can have flywheels interchanged it was a reasonable question. Let's just try to help each other find the information we need.
Now, DOES ANYONE KNOW FOR SURE IF THIS IS AN INTERNALLY OR EXTERNALLY BALANCED ENGINE.
Have a great day,