Project Update

Time: 8 Hours

So It has been a pretty busy summer for us…mainly for me flying and picking up extra hours so we can save for the propellor/spinner. I have done a lot on the RV that is worthy of posting on the blog. I have been cleaning up little items that were on my to-do list and checking them off. One item that I had added on the list a while ago was to remove all the zip ties I used and replace them with cable lacing. I wish I had just started off learning to lace and going that route from the beginning but I fell into the zip tie trance and how easy they are to put on. One problem with the ties is that they can chafe the wires as well as leave a sharp edge on the tail you cut off. So I watched a few videos and taught myself to lace properly and began to carefully remove the zip ties and replace with lace. I started on the firewall forward area including the engine. I then moved to the harder areas like the battery compartment and avionics bay behind the panel. It was a slow process but very rewarding to make it look professional. Here is just a couple of shots of how it looks with lacing.

Flap Actuator Safety Wire

Time: 1 Hour

One item that was on my list was to safety wire the top of the flap actuator where the rod end bearing gets bolted to the attach bracket. This was a service bulletin for earlier models and is now incorporated into the current plans. I held off on this until I figured I was done assembling-removing-assembling the flaps. One thing I didn’t think of was to pre drill the required hole in the actuator earlier when it was off the plane. So rather than remove it again I decided that I had enough room to drill in place. I used a 1/16″ drill bit and started at a 90° and as it bore into the metal I changed the angle enough to drill through the end clearing the jam nut. I then safety wired through the new hole then around the bolt holding the rod end to the bracket. This prevents the actuator falling out of the bracket if the rod end fails.

Tail Wheel Bolt

Time: 1 Hour

I had bought the Bogi Bar tow bar from Flyboy Accessories a while back and was going to get the machined tail wheel bolt as well. It was back ordered as flyboy’s has several custom machines parts and it was backlogged in the que to be made. It finally made the air and I ordered one as soon as they were in stock. This bolt incorporates two lugs that the Bogi Bar fits perfectly on and prevents that chance of it slipping off and gives a solid feel. I jacked up the tail and remember the stock bolt and replaced it with the new one from Flyboys. I had to tweet the cotter pin a little to get it to lay flush so it didn’t stick up proud of the lug so the tow bar would slide on. I love the look and how clean it is.

Brake Fluid

Time: 1 Hour

I had on my list of things to get done to add brake fluid to my brake system. I have read several blogs and watched a couple of videos on what was the neat way to accomplish this task. I decided I would try the method that pushes fluid from the lowest point up. So the idea is to use a small pump sprayer to push brake fluid from the bleed nipple on the caliper up through the brake lines and finally into to master cylinder. I went to Lowes and bought the sprayer and some 3/8″ clear hose that has a 1/4″ ID. I cut a two foot piece of the 3/8″ hose. I safety wires it to the nozzle on the sprayer. The other end I attached a spall piece of 1/4″ plastic line that was left over from my pitot static line. I safety wired those together. This is all to prevent leaks in the hose system as you add the fluid. The 1/4″ fits on the bleed nipple tightly and works well to prevent leaking. Once I pushed the hose on the nipple I turned it a 1/4 turn which opens it. With the sprayer pumped up I pushed the trigger allowing the fluid to flow through the hose, the caliper, the brake lines and into the master cylinder. I pumped enough to file it and push any air out. Once full I closed the nipple and removed the spray hose. With a firm push on the brake peddle I checked the firmness and made sure it functioned properly by spinning the wheel as it was jacked up off the ground and applied brake pressure stopping the wheel. Both sides worked well and I only found one small leak and that was due to a loose fitting. The pictures are for show and you want to pump all the air out of the sprayer lines so you don’t introduce more air into the lines. This process took only minutes to accomplish with this sprayer setup.

Baffle Sealing

Time: 4 Hours

One last step that I needed to do on the baffles is to seal up any gaps in the baffles where they meet to engine. The idea is you need to imagine a molecule of air and you want the molecule to cool the engine. That molecule needs to travel past the cooling fins of the cylinders to me the most efficient. If there are other spaces that the molecule can go then that reduces the effectiveness of the cooling properties. So to force as many of those molecules around the fins you need to close any other escape paths for them. One area that had a very large gap was on the right side of the forward baffle. I think it would have been tough to fill it with just RTV so I made a filler strip out of .025″ sheet. Once I had it to the shape I needed I drilled, deburred, primed and painted it to match. Most of the areas that need seal are pretty obvious to see for the not-so-obvious areas I used a light shining up from the underside of the engine to identify them. I used a grey colored RTV sealant, think caulking for environments that get hot and have contact with oils/fuels. It seals well and creates a good bond however can be removed when needed. It’s messy and hard to get it to look good but it is needed to properly cool the engine. I bought a couple large tubes that fit in a caulking gun to make it easier to apply. A couple areas that were too hard to access with the nozzle on the tube so I used a piece of 1/4″ plastic hose that was extra brake line stock attached to the nozzle to help get to those. I was able to use a wet finger to smooth some of the areas but others it was just too tight to get a finger on the seal. They aren’t beautiful but the will accomplish the task. I’m glad I was able to find a color that didn’t stick out like the red RTV that most planes use and would really be an eyesore.

I have a few areas that I want to clean up a little once they cure all the way. In the mean time I went ahead and cleaned all the baffle seals for the top of the baffles and installed them.

Overall I’m happy with how the baffles turned out. I think they will provide good cooling but will have to wait until I’m flying to confirm that.