[RVG8tor]

They have a remote device that will actuate things like the heat valve or oil coolers flapper valve. If you would run a Bowden cable to it this will do the trick for you without the hole in the firewall. Of course it costs more than a cable but it is a very cool item. I can't post pictures from this phone. It they have info on the website. http://http://www.tcwtech.com/control_valve_servo_kit.htm

 

[Flyguytki]

Very cool, I had wanted to do this with Ray Allen Servo motors but this looks like a much more feasible solution.

-david