Firewall Forward – adamsrv10

The Engine Roars to Life

April 17, 2024adambezanson1 Comment

In prepping for first engine start, I first had to get fuel flow testing done. I started out by putting 5 gallons of fuel in each tank sloshing it around a bit and draining it back out by pulling the sump drain. This flushed the tank of any construction debris, which there were only a couple of small metal chips found.

For safety sake, I had my extinguisher out and ready at all times, and I also bought a metal funnel which I bolted on a wire to with an alligator clip on the other end to ground to the airplane skin. On this same bolt, on the inside of the funnel, I attached a long piece of safety wire which went down through the funnel and was extra long to sit inside the container catching the fuel so it was touching the liquid as well. I also grounded the airplane with a separate wire to the metal hangar building, although this is less important as it is to have the funnel and container/liquid at the same potential as the airplane so no static can build up.

I then put 5 gallons back into each tank and ran each fuel pump, checking for leaks as fuel was circulating through the whole system. I adjusted my fuel pressure regulator to 46psi statically with the engine not running.

Then it was on to the fuel flow tests. First I pumped all the gas out by unhooking the return hose and running the pump until it cavitated. Then I collected what was left in the tank via the drain sump. A very small amount was left in each tank.

Then fuel was added back to the tank and again the return hose was used to fill a 1 Gallon glass container while the pump ran for 1 minute in a flight level attitude. I almost filled the 1 gallon in a minute.

Weighing it, I got a little over 4 lbs. Avgas is around 6 lbs/gal and the temps were in the high 40’s low 50’s, so the density of the fuel should be close to the 6 lbs/gal. Doing the math to convert weight per minute to gallon per hour nets me > 48 Gallons per hour delivery. I did each tank twice once from each fuel pump to make sure each pump can deliver at least 150% of what the engine needs at full power.

I then lifted the nose up as much as I could before the tail hit to simulate a nose up attitude. The 4 tests were repeated and netted close to the same results.

Then it was on to putting oil into the sump and filling the oil cooler.

Once things were oiled up, I left the top plugs out, disconnected the bottom plug wires, shut off the fuel and ignition, and cranked the engine to pre-oil the engine. This ends when you start to build up oil pressure as shown below.

After spending some time double checking that the SDS system was seeing the flywheel magnets, programming all the gauges for green/yellow/red range markings, etc… I was confident that I was ready to try to start the engine for the first time. I used my truck to strap the plane to just in case something happened with the brakes. Fire extinguisher at the ready.. and I asked a fellow EAA member to come by to keep an eye on the engine while I ran it for about 3 minutes. I ran around 1000 RPM for a minute and a half or so, and then went to 1700 RPM and cycled the prop a couple of times successfully.

A quick snap of the engine gauges while it was running. Everything seems normal.

I let the engine cool down and then ran it one more time before putting it away for the day.

I’ve since been able to do some short taxi tests to set the brakes and also calibrate the magnetometer. Now it’s time to do W&B and get ready for the inspection.

FWF Done!

February 20, 2023adambezanson6 Comments

Wow.. What a ton of work! I’ve now completed all the Firewall Forward plumbing and wiring. The only thing left to do is to put spark plug ends on the wires and maybe tidy up a couple of wires, but outside of that.. I’m done. I also took a little extra time to revisit my baffle material seeing I wasn’t completely happy with it the first time. I changed the left, right, and aft material so each was one contiguous piece of material. Previously they were broken into 3 pieces. The aft part had some puckering that I didn’t like as well, so was addressed with this update.

The next couple of pics are from the front.

The right side of the engine.

Boy does it really get busy in the space between the firewall and the engine. Especially when you have 2 coil packs for the spark plugs.

The left side of the engine.

Again busy busy.. It really took so much time not only to wire things, but to come up with reasonable routes and securing things.

Now its back to finishing the inside wiring and getting my panel powered up!

FWF wiring never ends

December 29, 2022adambezansonLeave a comment

Mostly been focused on FWF wiring. There are lots of connections to be made and properly securing the wires seems to take considerable time. Fabricating brackets.. etc..

Below you can see the metal L brackets I made along with a short straight metal piece to secure the #2 starter cable to the oil sump. The straight metal piece allowed me to mount the adel clamp for the #2 wire inwards, sort of on top of the sump. The adel clamps down lower allow for the lower voltage signal wires, mainly CHT and EGT, but also throttle position sensor wires to be secured.

I also secured the AC hoses FWF along with putting the ends on the compressor side of the hoses. I secured the hoses to the forward-most intake tube, a plate secured to the left side of the cold air sump.

The hoses connected to the FW and secured (although not in sight) to another metal bracket attached to the bottom of the cold air sump. I may also secure them to the engine mount in the middle of the run shown below.

**AC hoses ready to be connected to the compressor**

CHT probes were screwed into their locations in each cylinder. I then got to locating the EGT probes making sure they have clearance seeing they stick straight out of the exhaust pipe. I targeted 2 1/4″ down from the flange. I was able to locate 2 of the 3 on the inside of the pipes and #2 needed to be pointed outside due to the angle of the pipe and the heat muff being on this pipe giving few other options.

**Left 3 pipes have EGT probes installed.**

I’ve run spark plug wires to their destinations. The left coil pack services the top set of plugs and the right coil pack services the bottom plugs on each cylinder.

At this point the left side is just about complete. Still need to finish the spark plug wires and the Tanis wiring to each cylinder heat element. Time to work on the right side.

Below are some other pics of having a bung welded into the right side exhaust collector for the SDS O2 sensor installation spot. I had a local guy TIG weld this on for me.

I also split the forward tunnel cover into 2 pieces like most builders do with an Aerosport center armrest/console. I also mounted my bracket for the throttle and prop cables.

In unrelated news.. I received my Aveo Engineering Zip Tip wing tip light units. I ordered these at Oshkosh, so 6-8 weeks turned into 6 months wait time, but they are here and they look great!

Finishing AC hose routing, Evaporator shelf, front baffle “walls”, interior panels, and test fitting panel.

July 4, 2022adambezansonLeave a comment

I finished up the routing of the AC hoses down the right side of the fuselage. The hose going all the way to the tailcone dives down towards the floor and goes through the bottom most lightning hole to make sure it doesn’t interfere with the flap tube in the next bay aft. I placed a small piece of angle on the angle attached to the side skin, used nut plates to screw the 2 angles together and then utilized a nut plate to keep the hose from rubbing on the angle attached to the skin.

View of the metal piece riveted in all 4 corners of the lowest lighting hole with a bushing through the center for the hose to pass through.

The hose destined for the condenser scoop, goes across the flap tube area on it’s way across the tunnel and to the 1st bay under the left-most rear seat.

Hose continuing to the tailcone under the right rear seat.

I utilized Adel clamps anchored to the step to route the hose inward and keep it away from the bolt holding the step in place. It then makes its way aft to the tailcone.

Similar for the hose going from the condenser to the tailcone.

With the hoses done short of crimping on the ends, I started working on the evaporator shelf by using cardboard as a template.

I test fit the cardboard until it was trimmed correctly to sit between the longerons.

I then used the cardboard to mark up the fiberglass shelf and trimmed it, sanding a little bit to get a good fit. Shown here as well are the 3 holes matched drilled into the shelf brackets that get riveted to the longerons.

One other small task was to trim the upper cowl ramps and add a “wall” so that the baffle material could sit in-between the upper air ramp and this “wall” so it has something to push against.

**Using some scrap fiberglass to trim up a “wall”**

I then mixed up some flox and bonded the “wall” in place with a small “D” shaped piece to provide support against the cowl wall. This was repeated for the other side.

One nice day, I decided to head outside and paint the interior panels. I ordered the lighter tan ones knowing that I was going to paint them a darker color. I think they came out nice!

I ran into a snag with continuing with the evaporator install so I worked on completing disassembling the panel. I removed the wiring harness and separated the metal sub frame of the panel from the carbon fiber.

**Carbon fiber panel** **with avionics trays.**

**Metal subframe with shelf for various components.**

I spent some time getting the metal subframe in place, followed by the carbon fiber panel with the avionics trays. This first test fit was mostly done to mark the sub panel where I’ll need to cut away and reinforce making room for the connectors on the back of the 650 etc.. Not a whole lot needs to be removed just a small rectangle near the bottom and really just for the connectors and so the wiring harness doesn’t get bent too much.

SDS hall sensor protection and magnet mounting. Left side air for heat and Continued AC install

May 31, 2022May 31, 2022adambezansonLeave a comment

I’m probably being a little paranoid here, but I’ve decided to protect the wires coming out of the hall sensors up near the flywheel. These connections are needed to keep the engine running. I fear an alternator belt snapping and whipping around as it’s sort of hung up in the area for awhile cutting the wires. Of course, it would have to cut both wires for it to be a real issue, thus maybe I shouldn’t worry about this too much.. However, the solution really didn’t take too much time to implement. I bent up some 0.032″ metal to wrap around the sensor as shown below. One side has a narrower flange to accommodate the alternator tensioning arm.

Below you can see the hall sensor and the use of these small center locating punches that screw into a hole and mark the exact location to drill for the bolt.

Previously I had used this technique to locate the 2 holes for the SDS fuel pressure regulator on the firewall and forgot to write about it previously. I used a piece of scrap metal to drill and use as a template to drill the firewall.

I placed the unit down on the scrap metal and tapped it with a rubber mallet to mark the location location of the holes that needed to be drilled.

**You can see the punch marks on the scrap metal ready to drill.**

This technique worked perfectly and allowed me to drill holes for the regulator on the firewall that exactly matched the hole location on the regulator.

Back to the metal guard for the hall sensor… I punched the top side, drilled the hole, and once that hole was located, I installed the bolt and marked the location of the 2nd hole then drilled that and bolted it to the hall sensor mount. Below is a test fit of both bolts installed.

I re-used some aluminum fuel line to route the wires from the hall sensors through. I used an Adel clamp to secure it with the one of the bolts. drilled a hole through the baffle and installed a piece of angle on the aft part of the baffle for another adel clamp.

**Front part of the tubing with adel clamp.**

**Aft part of the baffle with angle and adel clamp.**

Below is the whole thing put together. Obviously the wires will ultimately be routed through the tube, but I need to remove the baffle and paint it at some point, so waiting to do that until after that is completed.

Also the DB-9 connectors on the end of the hall sensor wires are soldered on.. so another reason to delay putting them through the tube just yet.

My engine builder supplied a flywheel with the magnets for the SDS system already installed, but I needed to install the magnets in the dual pulley flywheel suppled by Airflow AC. I basically followed this blog linked on the SDS website. https://tasrv10.com/?p=2822.

Below is drilling the holes with the drill guide provided by Ross.

I wasn’t quite as lucky as the linked blog post and the hole sort of ate into part of the grove, but not completely.

I mixed up some 5 minute epoxy, as specified, and also applied red loctite onto one of the grub screws, which was inserted into the hole from the outside. The magnet was inserted into the hole from the outside. The grub screw was screwed down until the magnet was basically flush with the inner surface of the flywheel.

Once everything cured.. I decided to buy the Devcon Titanium putty recommended in the in the linked blog. It is expensive and you really need a very small amount compared to what is provided, but I didn’t want to skimp on this. I prepped the flywheel and applied the putty to each hole location as shown below.

I let the putty cure for approx. 3 hours and then sanded it using a combo of files and sandpaper. It was a bunch of work, but the end result is what is shown below.

One other thing left was to size up the air intake into the left size heat muff. I mocked this up with some skeet tubing I has lying around. It seemed like it would work, stealing some air from the left side intake,.

I cut a 2″ hole in the left snorkel.

I took a 2″ duct and flox’ed it in place over the hole that was drilled. Once cured, I re-test fit the skeet tube to the exhaust.

I then laid up some fiberglass cloth and some peel ply to glass over the flanges of the 2″ metal tube.

**Fiberglass** **Coth and peel ply curing.**

I was then able to get back to finishing up the condenser install of the Air conditioning. I utilized some scrap metal along with some construction paper to mark out the center lines of the connections on the aft side of the unit. I did decide to use some straight connectors that Airflow systems provided to put the connections in the first bay from the tunnel.

**Marking the center lines of the aft connections.**

I used some cardboard to enlarge the holes and make sure the holes were in the right position prior to drilling into the bottom fuselage. Everything seemed to be correct.

I then took the metal template and screwed it into position and prepared to drill the holes to mark out where the hoses are to be placed.

Then I screwed the AC scoop into position and test fit the aft hoses that go up into the fuselage. Everything worked out well as shown below.

**Holes drilled and connections inside in place.**

I installed some grommets into the holes to seal them as much as possible.

A view from the inside with the connections coming up through the fuselage skins.

FWF hoses, Oil door pin airfoil, and exhaust update

May 2, 2022May 2, 2022adambezansonLeave a comment

Most of the FWF fuel and oil hoses are complete now minus some Adel clamps that still need to be added. I’ve tried to annotate the pictures as much as possible to help show what all the hoses are.

Below you can see the main fuel supply comes out of the firewall bulkhead fitting on the left (pilots) side and attaches to the SDS post filter. In this picture is also one of the two oil cooler lines that connects to the engine.

Below is the closeup of the post filter clamped to the engine mount.

The fuel supply comes out of the post filter and continues on to the fuel rail after it passes through the baffling. Also shown is the fuel pressure line that comes back to a sensor, the other oil cooler line, and the oil pressure line.

A better view of both lines coming out of the oil cooler.

The blue hose is the oil breather line connected to the Air/Oil separator. This configuration will keep oil off the belly of the airplane. I also added an adel clamp on the firewall to hold it midway.

Moving to the other side of the engine, we have the manifold pressure line coming from the sensor on the manifold block. You can also see here the fuel return line coming through the baffling as it makes its way back to the fuel pressure regulator.

One of the add-ons I decided on was a remote oil filter adapter. This will make oil changes much easier with the filter readily accessible and with the filter oriented vertical, all excess oil will be in the filter when you spin it off preventing a mess. This does, however, require 2 additional hoses to get back and forth to the engine as shown here.

Below you see the Borla pressure regulator for the SDS system mounted to the firewall and taking return fuel (top right) from the engine, and returning it to the firewall mounted bulkhead fitting below the heat box on the right (copilots) side. I still need to attach a manifold line to the center of the regulator.

Looking at the engine side and the fuel block on top of the case.. you can see the supply, return, and pressure lines as they make their way from the rear baffle to the block. There is a T fitting in the supply inlet to provide the pressure back to the sensor.

Each of the cylinder is fed out of the sides of the fuel block like the 3 cylinders shown below.

I also drilled a small hole in the oil filter adapter to attach safety wire to when safetying the oil filter itself.. not done here as the install is all temporary for now.

One of the other things I needed to finish up as creating an airfoil of sorts to back up the pin for the hidden oil door. I used some air-drying modeling clay to form the shape that I wanted.

I then laid up a few layers of fiberglass cloth over the clay and allowed it to cure overnight.

I finished it off with some micro and sanded it smooth.

Another task I needed to figure out was how to feed air into the left side heat muff. With the AC compressor installed on the engine there is no good way to use anything from the air inlet area like the stock setup does. The only options I saw were to feed it from the aft baffle (like the right side does), feed it from the left intake snorkel, pull from the right inlet area (but this is also tight with the alternator over there), or add NACA vents to the lower cowl.

I’ve decided on pulling from the left intake snorkel. This does steal some combustion air , but the Showplane’s setup is designed to only need air from one side to be sufficient. So I will add a 2″ SCAT tube between the locations shown with arrows below. Of course, I’m going to need to get a 180* setup for the #2 cylinder heat muff from Custom Aircraft parts instead of the normal 62.5* one I have now. This will have air come in from the outside of the exhaust and intake tubes to the engine and the outlet will be on the inside of those tubes feeding the left heat box.

A rough mock-up of where the 2″ SCAT tube will go. There seems to be sufficient space between the lower cowl and the engine to do this.

A rough approximation of where the inlet to the heat muff will be.

In talking to Clinton about this, he’s also been fighting some cracking in the exhaust on the left side. He had previously sent me a support setup for the exhaust to help with vibration, which I have, but haven’t done anything with it quite yet. He asked that I install my exhaust and check for any interference with the intake tubes and in the end, I’ll need to send my entire left side of the exhaust back to him for modification to help prevent cracking in the future.

While sending it back, I’m also going to have him “stud” the heat muffs on both sides (as shown below) to allow for some better heat transfer. I didn’t know about this option prior to ordering and it apparently helps get some more heat for the colder months. The stock Vetterman exhaust is known to have too much heat, but that’s not always the case with the Custom system.

**Picture of Bob Lusslow’s studded exhaust that I’m going to have done.**

Fuel filter/cabin line redo plus FWF plumbing starts

March 20, 2022adambezansonLeave a comment

Back when I installed my fuel lines, Tom from AS Flightlines ( http://www.aircraftspecialty.com) really only had one solution to the SDS fuel filters. On top of the fuel pump module using adel clamps. I really don’t like having these in the tunnel for maintenance reasons. It seems inevitable that some amount of fuel will spill out into the tunnel no matter how careful I am trying to catch it all as I take this all apart for yearly service. Additionally, I placed the access panels on the tunnel sidewalls a little further aft and not perfectly aligned to the whole assembly, so access to the forward-most fittings is a bit challenging. Taking the top of the tunnel off, while doable, is a royal pain seeing there are throttle cables, etc.. routed on top of that. I really have always viewed this solution as something I’m going to regret and will spend way more time than I really should on each condition inspection. Also I can envision lots of curse words being used. Below is a view of the original filter setup in the tunnel.

**Original tunnel fuel filter arrangement.**

Since that time, Tom has come up with pre-filters in the wing roots, and moving the post filter firewall forward. Despite having some re-do.. I opted to take some time now to change and use this new configuration. Maintenance will be much easier and more accessible that way. If fuel does spill, it’ll be outside of the cabin. With just the fuel pump in the tunnel, there will be basically no reason to ever go in there very often at all, other than to remove the access panels and check on the pumps.

Of course that meant all new cabin hoses and some additional expense, but Tom actually helped out in this regard. I also went with some other arrangements that Tom has standardized on for routing, like having the supply come out on the left side of the firewall and return on the right. One thing that we did decide on was seeing we had to remake the hoses under my seats, was to re-use the hole I had already cut for one of the fuel lines. I cut this hole pretty close to the stock supply hose location and sided it just big enough to get a -6 hose swivel fitting through. Seeing both the stock and hole I drilled were too big for normal AN bulkhead fittings, I had to utilize the TCW fittings (https://www.tcwtech.com). Bob has come up with a washer with a neck/bushing on the inside that fits into the 1″ stock location so the fitting doesn’t fall through the hole. I also asked Bob if he could make me a custom one for the 25/32″ hole that I had already drilled. He made it the next day and had it off to me. I’d say I had a bit of shit luck with how these 2 washers fit basically perfectly. I really figured I was going to have to carve a half moon in one of them for clearance to the other.

**Supply and return fittings on the fuselage side skin.**

I installed 2 new hoses under each seat for the supply and return.

Below you can see the routing to the side skins. In retrospect, I really wish I didn’t route my brake line in the middle row of the systems brackets.. It would minimize hose crossovers.. In the end the right-most hose in the picture below passes under the brake hose with some clearance. The left-most hose is angled enough with the 45* fitting that it also clears everything.

I then spent some time re-locating the pump module. I used the “standard” length hoses from Tom to place this. I also noticed that I needed to raise the module up 2″ from the 3/4″x3/4″ angle I had placed on the tunnel sidewalls already.

**Using the hose lengths to place the pump module.**

In order to raise the module up, I decided on using some square aluminum tubing. I could some 2″x2″x.125″ material on Aircraft Spruce and ended up cutting 2 pieces. I re-used one set of holes and nut plates I already had on the angle for the aft-most tube. I then added 2 new pieces of angle for the forward tube as shown below.

**Using square tubing to elevate the pump module 2″**

I was then able to bolt the pump module down with 4 bolts into the square tubing with nut plates and AN3 bolts. I added a couple of adel clamps to the longer return hose as it made its way back to the selector valve.

Tom also sent along my FWF package with integral firesleeved hoses.

**Example of the integral fire sleeve hose**

I started on the fuel supply and routing it from the firewall to the post-filter to the fuel block on the top of the engine. This hose passes through the aft baffle with a grommet.

**Post filter location on engine mount vertical tube and routing through baffle**

**Supply hose to fuel supply rail on engine top. The T fitting is for fuel pressure back to the manifold block on the firewall.**

More FWF plumbing to come now that the cabin and pump are complete.

Completely baffled

March 12, 2022adambezansonLeave a comment

In prep for installing the baffle material, I used my go-to method of using construction paper to make templates for each piece prior to cutting the actual material. I targeted 2.5″ above the metal baffle material based on what others have done. I did a few test fits with the upper cowling on to make sure that length seemed like it would work. I tied to make the pieces overlap around the split points in the metal in case I ever need to take the whole assembly apart at a later time.

I then marked the templates with a line along the metal baffles to mark their position for reinstallation later on. I also marked out a line with enough edge distance for drilling 1/8″ holes to pop rivet the baffling material to later.

Once that was done, I removed the templates and cut out the material one piece at a time. I tried to cut such that the natural curve from the material roll would be in the direction I wanted the material to lay.

The method I found worked the best to punch holes in the baffle material was to first tape the template on the piece.

I then used the previously drawn line to place the template/piece assembly in place relative to the metal baffle making sure I had enough material for the overlap spots to the adjacent piece. I would use a drill to cut away the construction paper enough to mark the spot of the hole to be punched. I did the first 2 holes, then punched holes.. put the piece back into place with clecos and then drilled the remainder of the holes so I didn’t have to try to hold the assembly in position for the entire sequence.

**Drilling away the construction paper at the hole location**

I then used a punch to make the hole in the proper spot in the silicone baffle material.

**Punching the holes in the baffle material at the proper locations.**

Below are some pics of the final install. I did have to take some of the curl out of these pieces as they tended to curl inwards a little too much. I rolled each piece by hand in the opposite direction and sat some weight on the pieces to take some of the curl out. I also used some duct tape to hold adjacent pieces somewhat together. This will simulate the eventual RTV that will be used to hold everything together.

I then did something similar to the plans for the stock cowl to bridge the gap between the air intake tubes and the cowl. I used the metal strip material provided and curved it to match the round intake shape of the cowling. I then matched drilled 3 holes for #6 screws to hold this to the cowl. I cut some additional baffle material and used contact cement to adhere to the metal strips.

**Metal strips formed to cowl curve with baffle material adhered to it.**

**View of lower cowl with baffle material added.**

Below is a picture of the iniital test fit of this strip/baffle material fit. It seals up the small gap between the cowling and the intake tubes by resting on the inside of the air intake tube. I’ll likely trim this piece a little more for a better fit. Note also that I was sort of holding this in position to take a picture so the alignment is a little off, but you get the gist of what I am trying to accomplish here.

Baffle trimming and intake ramp finishing

February 2, 2022adambezanson1 Comment

In order to get the top cowling back on, the baffle needed to be trimmed. I saw two ways to do this, and I ended up sort of using both. I started by elevating the top cowl 6″ above the lower cowl. Care was taken to make sure it was aligned both fore, aft, left, and right to the bottom cowl. I just used some pieces of scrap wood and clamps that I had lying around on each corner on the outside of the cowl. I measured in multiple locations along the horizontal split to be sure I was satisfied before moving on.

I then made a tool out of a tongue depressor and an aluminum block I had. I taped a sharpie to the bottom of the block and adjusted the stick to get exactly 6″ from pen to top of the stick. I didn’t take any pictures, but the idea here is that you have enough room (with the 6″ elevation) to get your hands/arms inside to hold the stick at a 90 degree angle with the sharpie along the inside of the baffle. Holding the stick on the inside of the upper cowl, you move it aft tracing the contour of the top cowl onto the baffle which will serve as a trim line.

I then trimmed to that line. That basically got me to flush. One could certainly add some extra to the length of the stick to get the the gap you’d like to achieve. Instead, once the initial trim was done, I utilized the 2nd method of paper clips all along the baffles. You barely stick them on and then place the top cowl into position. They slide downward and give you an exact indication of how much gap you have at that location to the top cowl.

**Paperclips in position to measure gap**

Below you can see the results of the first attempt. You’re shooting for somewhere between 12/32″ and 16/32″ gap per the plans. At each paperclip location, I wrote the number of 32’nds needed to get to 12/32″ by measuring how high each paperclip was above the edge of the baffle.

Those measurements basically were used to draw a new trim line.

I ended up doing this for a couple of cycles until I was completely satisfied with the gap all the way around. Making smaller adjustments in specific areas as I went. Below isn’t the best picture, but it was the results of the baffle trimming with a gap to the top cowl.

I fabricated the clips and drilled them into position per the plans. I’m holding off riveting most of this stuff until later.

Now that the baffles were trimmed, I decided it was time to affix the top cowl inlet ramps. I placed them into position with clecos and some scrap metal strip to hold them in place at the front.

I then test fit the cowl and had to trim the outer side baffles more to account for the curvature. I did get somewhat lucky due to my cowl being so far forward based on my prop/spinner setup compared to most. The ramps didn’t require trimming at the prop governor to at least test fit. I did end up trimming around to give some more clearance, which I’ll foam in later to provide a good backing for baffle material.

**No initial trimming required for prop governor.**

Once I was happy with their location, I epoxied them into place. Later I will layup some cloth, but for now just epoxy to hold them in position. I also did a single layer of cloth and some peel ply on the inlet circle just to hold that area into position.

**1 temp layer of tape with peel ply on the outside.**

I then laid up 3-4 layers of cloth for the underside of the circular inlet.. Placed that into position and let it cure. I sanded down the outside area and added micro. Once that was cured, I sanded to a smooth finish.

With the upper ramps completed enough for now, I moved on to customizing the center baffles. I started with the right side, seeing it’s the easier side without compressor interference to deal with. I cut the stock baffle leaving just enough flange to rivet a new piece that would angle toward the inboard side of the inlet. I first made a template from construction paper and got it as close as I could. I transferred to metal and worked on trimming to get a good gap to the upper inlet ramps.

**Transfer template to metal and test fit.**

I then spent some iterations trimming this custom piece to match the curvature of the upper inlet ramp with some gap for baffle material. Below are the results.

To hold the inboard side in place I fabricated up some 3/4″ x 0.125″ Angle. Seeing there was a slight bend in the baffle I just created near the inlet, I marked a cut to match that bend in the angle. I marked and cut out a “V”

**Bending the angle to match the bend in the baffle.**

Below is the end result after match drilling and cleco’ing the baffle to the angle.

I utilized 3 screws to tie the aft piece of metal holding the carbon fiber ramp to the front pieces, including the piece of metal that runs under the carbon fiber ramp. I trimmed the excess away on the inboard side of any carbon fiber and metal plate so it didn’t protrude past the angle.

I then did a similar thing using a template on the left side. I decided to use one piece of metal to wrap around the governor and bend around the AC compressor belt to box it out of the inlet area.

Once I was satisfied with the paper template, I transferred it onto metal, cut it out, and made the needed bends as shown below.

**Initial trim of the custom left baffle.**

I then worked to fabricate another short piece of angle with a notch cut out for AC belt clearance to hold the inboard side in place. I drilled 2 holes for #6 screws to attach to the stock baffle that I had cut off and left a bit of a flange for connecting my custom piece to.

**View of left ramp area with baffles screwed together and cleco’ed to the angle**

**Front view showing the angle and 2 #8 screws holding it in position, allowing clearance for the AC belt.**

**View of the finished up left ramp area.**

**Both ramp areas complete (beside riveting everything).**

**Final picture with top cowling in place.**

This was a lot of work!

Intake part 2

January 10, 2022adambezansonLeave a comment

Now that the basic shape of the left intake tube was formed, it was time to sand it down to perfect shape. I used mostly the Permagrit sanding blocks for this task, and it was relatively easy. Of course, at some points I had to put the lower cowl on to make sure I had clearance to it. I also carved out a bit more in the back for the AC hose connections to the compressor.

I then laid up 4 layers of cloth and put some peel ply over the top and let the tube cure overnight.

Of course prior to doing this I covered the foam in packing tape as a release agent and also sprayed some silicone based release agent on that for good measure.

Once cured, I removed all the foam inside of the tube and test fit it.

I then cut some cloth to close out the top part of the tube where I had cut for clearance to the compressor. 4 layers again were laid up and peel ply placed over the top.

Once cured I test fit the tube once again to make sure things looked good. below you can see the blue sharpie lines that I used to mark the cloth for cutting pieces to shape.

**Aft view of bump in for AC hose connections**

Then it was time to wrap a single piece of cloth to span the gap between the two tubes to join them back together. You can see the black line I marked for alignment. I also used a jack to allow the tube to sit on vs. having gravity pull down on the tube while this was curing. I used a single layer on the outside, because clearance to the cowl is a bit tight. Once this cured, I placed a thick layer of flox on the inside of the tube to fill the gap and create more strength in this area.

One of the other tasks that needed to be done was to redesign the air ramps seeing I’m using the Showplane’s cowling and the stock metal ramps were cut out for this intake system. I fabricated a .032″ thick piece wide enough to go under the baffle angle and still protrude enough to serve as a flange for the new ramp. This will be bent downward somewhat depending on the angle between this and the from of the intake. It’ll provide a nice flat surface for attaching the ramp material to with screws.

I also bent up some of the side baffle material to provide 1 screw location. I also decided to fabricate up a metal piece that sits up front on top of the intake area. It has a bent flange that will rivet to the side baffle material. I’ve left everything to the inside (closest to the flywheel) long for now. Once I get the center baffles completely figured out this area will be trimmed and I suspect some aluminum angle will be used with some screws to connect the front metal piece to the aft piece I made with screws.

**Picture of ramp area prep for screws and carbon fiber ramps.**

I then cut some carbon fiber material I bought for the ramps to fit in the ramp area. Again, leaving the inboard side long for now.

I then match drilled everything, added nut plates, and screws to hold everything down.

I put the center baffle material in place after cutting it somewhat. This will need to be angled back towards the intake opening. In fact, I may cut the piece coming out towards the flywheel and rivet in a new piece of my own at an angle to achieve this.

**Right** **Center baffle piece in place**

I really had to trim away the left center baffle piece. It interferes with the AC compressor quite a bit. So I decided to cut the forward most section completely off, leaving enough material to rivet more metal to later, and also the notch for the aft part of the prop governor. Later, I’ll work on a custom piece to go over the prop governor and along the ramp to the intake area.