Fully counterbalanced cranks

[Damo]

Has anyone had much to do with fully counterbalanced cranks?
Is anyone aware if there was one made for the E15?

I have been doing a little research, and apparently Nissan made some for the L series engine back in the day (Probably for the SSS's), just wondering if this extended to the E15's.
Still seems to be limited info on the net that I can find.

For those of you who may be unaware, a fully counterbalanced crank has the same mass of weight opposite to every crank throw on the crank. This makes every crank pin balanced which is good eliminating high rpm harmonics, and allows main bearings to survive big revs.


Damo