Saturday, October 11, 2025
Panel Assembly!
Thursday, October 9, 2025
Exhaust Hangers & Panel Labeling
The exhaust tailpipes need to be supported with rigid, yet flexible, supports to allow the exhaust to move a little with engine vibration (especially on startup) without moving out of position enough to hit the cowl. This is accomplished by clamping steel tubing to the exhaust and engine/mount and using high pressure rubber hose to tie the two pieces together. The space in between the two steel tubes is only about 1/4", and the rubber hose spans that space and allows just a slight amount of movement.
The steel tubing that came with the exhaust kit wasn't long enough for my liking, so I got some of the same stainless steel on Amazon and made my own to the size I wanted. The tubing is scuffed up, and a slight flare is made on the end to help keep the rubber hose from sliding around too much.
The vertical support goes from the tailpipe up to a bolt on the engine sump. The horizontal support is a little different than what the plans show. The plans show that you can tie the left and right exhaust to each other in the horizontal plane, but the new nose gear design with the elastomer doesn't have any space to allow a support to go from one tailpipe to the other. I verified with other builders that the only real option is to go the opposite direction and tie the tailpipe to the engine mount. That's not ideal because you're attaching a moving engine piece to a mount that doesn't move, but people say it actually works just fine. These simple connections took hours to do between the two sides - those tailpipe clamps were far from easy to work with! The setup is nice and rigid, but with a small amount of wiggle room.
Sunday, October 5, 2025
Heat Muff & Panel Paint
I need to get the exhaust finished up so I can plan out all of the other wire and hose runs for the engine (the exhaust takes up a lot of space, so everything else needs to be planned around it). I just made a wild guess and made 6 heat sinks to go inside the heat muff. There is room for more if down the road I find that I still don't have enough heat, but I imagine this will be plenty.
The heat muff doesn't leave many options for where to put it. It's about as long as the straight length of pipe it goes on, so regardless of how it sets relative to the engine mount, it's basically going to set where it's going to set. I'll have to snake the scat tube around the mount.
Thursday, October 2, 2025
Misc Wiring & Exhaust
Doing some catch up documentation from the last few days of 10 minute here and there build sessions.
I can't remember if I mentioned before, but my 3D printed fan guards turned out very nice, but when I screwed them down onto the glare shield, they curled up around the screws because I had made them so thin. 3D printed guards are probably not a great solution since I want them to be low profile. I think I'll probably end up getting them cut out of aluminum instead. I'm just waiting to see if I have anything else I need cut before sending the design to sendcutsend.com. I went ahead and spliced the fan wiring together so I could just run one pair of wires to the panel. Once the panel is in place and the canopy back on, I'll figure out how to deal with the slack needed in the wires for the canopy opening/closing arc.
I hooked the fans up to my bench power to ensure they worked. I'm glad I got the thicker fans. They actually move a lot of air!
One thing I've procrastinated on is installing the tailpipes on the exhaust. I was waiting on that because I needed to have an idea of where the lower cowl exhaust exit opening would set to ensure I had good clearance around the pipes. The pipes have an angle in them, so spinning them in place means there's a huge range of where the ends can exit the engine compartment and what the clearance to the fuselage and cowl is.

The right tail pipe will be where the cabin heat muff is. I need to get this in place next because the bulky scat tubing to and from it will dictate where I can route some of my wires. The heat muff is just a thin cylinder that goes around the tail pipe, with fresh air feeding in one side and then going out the other end to the firewall cabin heat box.

One of the complaints about this design is that in cold regions it doesn't provide quite enough cabin heat. Some people put a second muff on the other tail pipe, but I've seen those installs and it adds a ton of scat tubing to an already cramped area. Instead I'm going with the increased surface area approach. A common solution to increasing surface area is to stuff steel wool into the muff around the the pipe, but the complaint with that is that it decreases the volume of air that can get through to begin with. I saw a builder who instead added stainless rings with fingers to the pipe. He said it has worked really well, once he found the right number of rings to add on (he had too many at first and was cooked out of the cockpit).