RE: Header Tank vs Perry Pump vs nothing - Bobcat 50 prop'er
Some points:
Header tanks are great for keeping air out of the line (Heli acrobatics), but wont improve fuel delivery.
A long exhaust diverter will add a bit of back pressure and could overly richen the mid range or ruin transition.
A Perry pump on a Super Tiger carb will overly richen the mid range or ruin transition to the point the the engine will quickly die at part throttle.
You can dial down the pressure with the low and high speed needles but you can't reduce the mid, your a the mercy of the carb's fixed metering.
Adjusting the pump pressure down will help, but that defeats the purpose of the pump in the first place.
A blader tank will keep out air in the fuel line, but wont improve fuel delivery.
A 11X6P APC will reduce the load on the engine and keep it cooler. That's what I ran on the OS 55AX, the ST is about the same power. The 11X7p ran hot.
Run the engine nose up and see what happens in a few moments, does it respond to leaning? How is it when back to level?
A Uniflow tank layout works in some cases, but in this long fuel run I think it will be a detriment.
There is the Cline on demand regulator,and I know you want a gizmo to fix all your woes, but you haven't exhausted other avenues as you can see.
Keep it simple. Besides the Cline is ugly hanging in the breeze right next to the carb.