Awhile back I started trying to sort out a better place to put a second cabin heat muff. I eventually ordered one from Rick Robbins, and it arrived a few weeks ago. Today I finally finished fitting it, and installed the SCAT tubes.

The custom 7" long muff will get its air from a hole in the right baffle floor.


This shot is looking up, with the air coming into the muff on the right, and exiting on the left.


I've got a heat shield between one of the exhaust pipes and SCAT tube. This piece of SCAT should probably be shortened a bit. This piece of SCAT just touches the cowling. I should probably go down to 1.5" diameter SCAT, as this would give me another half inch clearance, and I've got a report from an RV-6 flyer in Minnesota who reports that if too much cold air is going through the heat muff that you don't get as much heat as you do if you restrict the amount of airflow. He has 2" SCAT tube, found found that he needed to block off 80% of the opening. He thinks that 1.5" diameter SCAT is more than big enough. But, I'll worry about that after I get flying. No more mods that aren't strictly required.


I knocked off several more smaller items on the big To Do List. But I found a few more items to add to the list, so the net gain was only about two items.