No room to make a cooling box. Space is premium in the GP Christen Eagle despite it boxy looking cowl . Thats why I had the ignition battery inside the plane just behind the firewall next to the fuel tank . I was thinking of velcroing the ignition unit to the engine box on the carb side with some foam between for vibration insulation but that may not be enough for isolation . May have to end up placing it insde the plane behind the firewall but then i need to drill out another hole in the firewall for the ignition cables etc.