Manifold pressure line

Posted on by Neal

Tonight I installed the cushion clamps to secure the manifold pressure line, and the rubber hoses to route pressure to the e-mags.

I found I had to make an adjustment to the routing of the line, so I removed the engine-side connector, rerouted, then reconnected the line. That also led to moving some clamps around, but I think I have a good routing now. Once the oil cooler scat tubing is installed I may have some interference, but I’ll deal with that later.

Installing the rubber tubes was kind of a pain, as access to the mags is somewhat restricted. But I get the feeling it will be even worse when I have to do some wiring back there.

Rerouted line to work around the engine mount
The rubber hoses installed
Final routing on the left hand side

Oil Pressure and Manifold Pressure

Posted on by Neal

Tonight I installed the oil pressure sensor line, and started on another modification to move the manifold pressure sensor. This modification is courtesy of Steve at Aircraft Specialties and makes use of the unused port on the Vans bracket. It’s a more elegant solution for providing manifold pressure to the two E-mags, in my opinion.

The oil pressure line was straight forward, just connecting two fittings with a hose, and torquing the b-nuts.

The manifold pressure line was slightly more involved. First uninstalled the pressure sensor from its original location on the right side of the firewall, and reinstalled it on the left side, using the spare port. I hunted around and found a spare plug, and then installed that along with the Aircraft Specialties supplied fluid fitting. I made up the rest of the fittings, routed the lines across the engine compartment and installed the line at both ends. Now I just have to locate and install the cushion clamps to secure it in place.

Oil pressure line connected and torqued
Manifold pressure line routed across the top of the engine compartment. The two needle fittings will connect to the two e-mags using lengths of rubber hose
The lines routing to the Vans bracket
Top-down view of the Vans bracket. The fitting on the right is a straight fluid fitting, despite looking like it’s 45 degrees in this picture. Sensors from left to right: oil pressure, fuel pressure, manifold pressure

Fuel lines

Posted on by Neal

Tonight I finished installed the remaining fuel lines, torquing them and marking with torque seal. With that, the fuel system is plumbed from the wing root, through the fuselage, firewall, engine-driven fuel pump, fuel transducer, fuel control, fuel spider, and out to each injector. Once the wings are installed, the final piece is the short connection from the wing root to the fuel tank.

This felt like a bit of a milestone, so I took a selfie from under the engine.

Firewall exit. After fretting about clocking this fitting to 5 degrees, I have no idea why that clocking is even necessary. Perhaps it’s related to the EXP engine changes
Fuel pump connection
Fuel controller connection
Looking up from under the engine

Baffle seals

Posted on by Neal

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.

Riveting the seals
Finished result
Baffle seals installed around the governor
Left side of the right air inlet
Right side looking aft

Baffle seals

Posted on by Neal

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!

The rubber roll with the baffle seals pre-punched and labeled
Baffle seals clecoed into position
Clecoed baffle seals. In the left foreground is part A which I installed with the label facing inboard

Baffle air ramps

Posted on by Neal

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.

Practice part. The curve is ideal
The actual part. Not a great bend on this end, but it fits great.
The aft end with a tighter radius. No cracks this time
Air filter and cover installed

Baffle air ramps

Posted on by Neal

Tonight I had only a few minutes, so I riveted the right air ramp into position and glued on the template for the left air ramp. I used a pop rivet in the aft-most, inboard hole, because access by squeezer was tight, and I didn’t want to use my rivet gun for fear of bending something.

Riveted right air ramp

Baffle air ramps

Posted on by Neal

Tonight I shaped the right hand air ramp.

This required sticking on a paper template, then, following a sequence of bends, shaping the piece until it conforms to relatively smooth curve. It’s a conical shape, so one end is a much tighter radius than the other. I managed to get the shape fairly close, but I ended up cracking the end with the most narrow radius. I stop drilled the crack, then filed out a relief notch to mitigate the risk of further cracks.

I then match drilled the holes into the baffling, and dimpled them. Dimpling the aft most holes was a little annoying because it was too far from the edge to use my squeezer. I used a pop-rivet dimpled instead, which doesn’t give great results, but good enough in this case.

The right air ramp with template glued on
Shaping the air ramp by gently tapping a block of wood against the various marks on the template
After shaping the air ramp
Match drilling the air ramp to the baffling
Match drilling
Match drilling the aft holes was almost impossible given the geometry, so I clecoed the ramp to the outside a drilled the aft most hole