I will be ready to install bellcranks in my Brodak full body Oriental and Ares.
I have heard that a 4" bellcrank gives the feel of power steering. Since I have the 3" cranks with the kits, is there any advantage to switching to a 4" crank?

Thanks Bob, Makes sense. Just though I'd concider it while I'm at a point where I have two planes on the building board, at the time of installing bellcranks.
3" have served me well so far.
I have an old  CLC  Super Chief/OS.46sfs Dixon modified for building in the future, may do the 4" BC at that time.

As has been said by others, I too like the 3" in smaller ships withthe shorter horns.  It is important to use the comparable horns with bellcranks according to size.

On the "big" planes, a 4" BC is about mandatory.  I just don't think a 60 plus oz. plane with a comparable size engine would fly as precisely using a 3" BC.   The whole set up benefits  from the leverage and ratios. 

Interesting that Tom Morris sells 3 1/2" BCs.  I have found them to work quite nice in the 'tweener" size planes.  Like the 56" Skylark which was originally .35-.40 powered, but often gets a .46 now!

Bill <><

Ward speaks the truth!

And I'll chime in that equally important, or maybe even more so is to have a rigid carbon push rod, rigid horns and rigid flaps & elevators. If you use soft contest balsa on the flaps & elevators, stiffen them up with silkspan & dope, especially if you are just going to use plastic film covering on top.

Heck, I'd take a sturdy control system with a 3" BC over a wimpy system with a 4" BC. If the control system is spongy or springy, it doesn't matter a lick what size BC or horns you have, they are going to flatten out in the heavy loads like Ward describes.  

EricV

When I can fit them in (a trick in any case!) I use a 4 in bellcrank in my 1/2A's with the idea of slowing down the controls rather than the idea of having more power in the controls.