Did you mount the aircooler flaps like the plans say if you did then all you have to do to increase airflow is sand the nacelles until you it is wide enough to pass enough air to cool the engine. Of course if you spilt the seam between each flap then they would bend easier without heat. I personally cut each free from the backplate then used baydoor hinges and moved to where I wanted them the just a touch of CA. And wala you have a more scale looking aircooler flap plus it is opend a lot more for air circulation. Just my 0.02 worth. Be sure to fuel proof the blocks for the flaps.