I had previously installed a TCW linear servo to control my oil cooler butterfly valve. In thinking more about potential failure modes, I decided to swap out the servo for a push/pull control cable. This gives me one less thing that can fail and lead to an emergency. It also removes a knob from my panel as I can mount the push/pull knob below the panel in the location provided by Aerosport.
I fabricated a new longer arm from .25 2024-T3 to reduce the radius of deflection of the cable and to provide a 2″ travel distance (the same as my parking brake). I designed the arm to be drilled through the axle of the butterfly valve (instead of just clamping which could slip). I had some #3 stainless screws which fit in a #40 hole.
I set things up so that the valve is in the fully open position when full forward. Pulling it back restricts the flow in the same way that pulling the parking brake sets the valve.
The butterfly valve contacts the turning vane in the fully open position and the b-nut contacts the cable sleeve in the closed position.
I used a firewall pass through to secure the cable.
I mounted the push/pull knob below the push/pull cable for the parking brake.
