Today I welded more on the oil cooler support tube. I made a nice little foot on the end that should help distribute the force and vibration.
As I mentioned in an earlier entry, the flap cable terminates at the torque tube in an interesting way. Bob specified a shackle with a 1/4″ hole, but a 3/16″ bolt. I made some bushings for this junction earlier, but I didn’t make them correctly. It turns out that each shackle requires two bushings, and the flap horn itself still keeps the 3/16″ hole. To help make the bushings as true as possible, I cut them with the circular pipe cutter. To help reduce the stress on my hands, I chucked up the 1/4″ 4130 tube in the drill and let it do the turning. That method worked pretty well.
I dabbed a tiny amount of JB weld on the bushings where the join the shackle. The goal here was to keep from losing the bushings between now and flying time. Once the airplane is assembled, the bushings will be held in place by the bolt.
Next I tried a few different ideas for installing the tap for the manifold pressure. I need to go from 1/8″ pipe threads to 1/4″ hose, which leaves me with plenty of options. The cylinder end is going to be exposed to some fairly high temperatures. When the engine is running the temperatures should be fairly moderate, but after shutdown that area will probably be at least 200 degrees.
This straight barbed fitting isn’t going to work, and I’m not sure that a 45-degree barb fitting will be able to turn in the confined space.
Here are a few pictures that I took to send to the exhaust folks to see if they think a muffler will fit. I’m including them here for reference.