Today we installed nut plates on the spinner flanges, both the forward and aft plates.
Spinner
Spinner
One of the challenges with the spinner was to locate the screw holes on the forward spinner plate. After some experimenting and some research, we found success with using the ball magnets that shipped with the finish kit. I believe these are designed for the wheel pants, but they come in handy for the spinner holes too.
By taping magnets to the inside of the spinner plate over each hole, the spinner can be installed, and ball magnets can be used to locate each hole to be drilled.
This worked well enough and we drilled the holes today.
Exhaust and Cowling
Tonight I made some more progress on the exhaust system, while dad worked on fitting the air ramps into the top cowling.
Cowling and Exhaust
Today we continued working on the cowling and the exhaust system.
While Dad handled the sanding and fitting of the cowling, I worked on setting up the exhaust system. First I assembled the support clamps, then applied anti-seize lubricant to the sleeve and ball fittings, then set it up underneath the engine.
With dad’s help we were able to mount the pipes onto the cylinders, doing up the hardware finger tight.
Using a roll of 3/4 inch electrical tape, I set the spacing correctly and installed the support clamps on the aft edge.
Dad did another round of filling today, as there is still a ways to go to achieve the alignment we need on the cowling air inlets. It’s amazing to watch him work, knowing just what’s needed to get the perfect fit and finish. At 79 years old he’s still putting in very long days, with no complaints.
Cowling Air Ramps, Exhaust, and Oil Door
With my dad back in town and helping with the cowling again, we made progress today on a few fronts. Dad worked on installing the top cowl air ramps, and started on the oil door, while I focused on the exhaust system.
Before the air ramps could be installed, we needed to address the alignment issues with the front of the cowling. In a couple of sessions, Dad applied filler to the edges of the air inlets, and trimmed the air ramps to fit.
Meanwhile, I installed the first section of the heating system, the heat t-fitting. I left the clamps loose for now, as it’s hard to tell if this will need to be finessed into position later. I then drilled out a couple of rivets, and installed the FF-00084 cover. After some puzzling, I realized that this stops the hot air from escaping the system when the passenger vent is closed, and the pilot vent is open.
We then found and trimmed parts for the oil door.
Exhaust system
Today I started on the exhaust system by cutting the scat tubing to length, and making up the flared-tube exhaust support fittings. No issues or challenges with this step, although I wonder how well these fittings will work. Hopefully they will grip the inside of the hose enough to hold on, I have read a few stories on vansairforce.net where these have let go. We’ll find out I guess.
New oil return line
Today I installed a new oil return line on the #2 cylinder (front left).
The original line from Lycoming interfered with the snorkel, which is a know issue with the EXP119 engine. Conveniently, Aircraft Specialty make a drop in replacement line for just this problem.
I removed the original line, and test-fit the new one. It worked great, but I couldn’t quite get a flush fit between the flared tube end and the fluid fitting on the engine. After some fiddling around I guessed that the problem was the fitting clocking not being exactly right for the new hose. I removed the fluid fitting, cleaned the threads, and reinstalled it (Loctite 567). Once I had close to the right torque, I slowly rotated the fitting while testing the fit of the flared tube. It was easy to check the alignment by just feeling how much resistance I had on the b nut. Once it fit freely, I stopped rotating the fluid fitting and torqued everything up.
Clearance from the snorkel is perfect.
Baffle seals
Today I riveted the baffle seals into position.
The seals are secured with pop rivets and washers. The washers prevent the rivet head from simply pulling through the rubber.
No problems with the riveting, which was made easier with the snorkel removed.
Baffle seals
Today I cut out the baffle seals and clecoed them in place. The seals come in a roll of rubber material, with the shapes pre-punched. It took a little time to cut out each shape with a razor, but it was easy to do. Each part is stamped with a label, and they are installed from part A to M.
The baffle seals press against the top cowling forming a seal, and forcing the airflow down through the cooling fins and into the ducting that cools engine components. Any gaps in the baffle seals means inefficient cooling and higher engine operating temperatures.
Based on some vans Air Force threads, I was ready for some of these seals to need to be switched, or flipped, or something. What I found was that if installed with the labels facing outside, everything fit just right. Except for part A, which appeared to be reversed. After a bit of deliberation, I decided it fit best with the label facing inwards. Once I have the cowling on, I guess I’ll find out!
Baffle air ramps
Tonight I shaped the left hand air ramp. This was trickier than the right hand side because the ramp is part of the air filter cover. Bending the ramp risks damaging or bending the cover. I practiced on a piece of scrap, and when that came out almost perfect I got started with the real piece. The first bend went well, and the second was going well also. However when I moved to the third bend line I noticed that the cover had developed an unwanted bend and a twist. I carefully worked the unwanted bend out, and carried on with the process.
The end result was acceptable, but not my finest work. I removed the paper template, match drilled the one screw hole, deburred, dimpled, and installed a nut plate.
With the part complete, I installed the air filter and cover, and verified everything fits correctly. Then I took it all apart again, as I’ll need to replace the oil return line.
