When I made the entry for yesterday, I was dead on my feet. After a day or two of standing/working, I sometimes don’t have the patience to write well, or clearly, and I certainly don’t have an excess of desire to deal with photos. I’m sure there’s some fancy wordpress widget that can handle it, but when I started this project, ‘blogging’ was a new buzzword heard only in elite circles of of the technorati, and as yet had no good tech for displaying images other than the tried and true html code, which is what I use, and still use.

Along with that, when I’m on the “here be monsters” part of the instructions, I don’t often stop to take photos because I don’t want to lose my train of thought. I envy the photojournalist’s muscle memory of shooting constantly while engrossed in other activities. I just ain’t got it.

So this entry is just a slew of photos, with comments as to what was going on, and hopefully they’ll tell some of the story of how I arrived at a solution for the interlocking puzzle of front-governor, snorkel, and baffles.

Like I’ve mentioned before, the O-540 front baffles from the RV-10 kit get dragooned into service on this particular -7. The biggest headache is finding all the chickens, all the eggs, and turning them into ducks, which go in a row. Barnyard metaphors aside, it becomes an exercise in problem-solving to figure out what to do first. The first thing to do is to fit the snorkel. I won’t go into that here, because it’s been described elsewhere, but the only way to get a solid enough structure from which to take any reference for cutting or fitting the front left baffle is to get as far as you can on the snorkel. This means riveting the side baffle and drilling the left front inlet ramp to fit it, with all the bends and adjustments done.

Like everyone else says, don’t trim the front of the inlet ramp until the last minute, because you’re going to need it to form the front air filter retainer angle, which is simply a bend in a section of the inlet ramp where the air filter edge stops. Mine’s just on the nice side of acceptable for this purpose. Making this bend also stiffens the inlet ramp, and that’s a good thing, because by the time you’ve cut the gaping maw of the air filter opening, things get a little wobbly.

From there, you can fight with the snorkel and the air filter retainers, and at the end of the process, you have a detachable airbox whose structure provides a rigidity suitable for measuring the final inlet floor angle.

This angle was marked on the engine case, but sure enough, it drifted around a degree or so during the install.

See that flat pad just below the governor? That’s where I marked the initial angle of the inlet ramp. This is done with the lower cowl on, because it’s necessary to make sure the inlet ramp comes up to the inlet on the fiberglass lower cowl. Also, don’t do like I did, make sure you cleco all your baffle-to-case hardware on so you can work without every bump moving something out of line.

I didn’t photograph this process but the way I measure’d the angle is by using a cheap plastic angle measuring thing (don’t remember the actual name of the device) which is like a protractor with a couple of arms and dials on it. You can use whatever you want, but the reference for this to line up the vertical are the two aft studs for the governor mount. With one arm of the device on those and the other laying on the inlet ramp floor, you get what you need. The governor should be off at this point, to give you room to work.

From there, it’s no big deal to transfer that angle to the O-540 front baffle, which has a sharper angle than the 360 baffle, and cut off the excess to line it up with the governor and the inlet floor.

With that done, you have a front baffle that more or less fits where it’s supposed to go. I didn’t take photos of the air filter retainers, VA-132-C and D, which hold the air filter in place inside its hole, but you need to make sure you have these on when you’re doing the final position of the baffle.

This photo shows the lower edge of the baffle laying along the inlet floor just inboard of the inboard air filter retainer. This is important, because the left front baffle needs to be detachable and accessible, as does the filter retainer.

The factory-formed tabs on the baffle are no longer there after the bottom has been cut away to match the inlet ramp angle, so you have to replace them with something. This is the first attempt. Initially I figured I’d only need to do the long side, but this isn’t really a good solution.

This little whisker proved to be the source of much head-scratching, pondering, and measuring. This forms to the angles of the baffle and the inlet ramp, replacing the tabs that were sheared away during the fitting of the baffle.

Like so. This provides a good place to mount the platentuts that hold the baffle to the inlet ramp. It looks fine now, but getting to this point was insanely difficult. At some point in the build, you realize you’re off the map entirely, and you wind up being designer, engineer, and installer, sometimes all on the same day.

This is why I can’t stress it enough: If you’ve never built a plane before, or you don’t have a lot of experience with fabrication or mechanical work (like working on airplanes, for instance), don’t deviate from standard configurations or construction, because you’re going to get your ass kicked. The whole reason I’m in this mess is because I bought a weird engine. If I had to do it over again, I’d have gone with the recommended 360, with its aft-mount governor. Would have saved two or three weeks, possibly more. Seriously.

Anyway, back to the narrative. With the angles cut, bent, deburred and drilled, the platenuts go on, then this piece gets riveted to the inlet ramp.

The right hand side is similar, except in this case I’m using a slightly thicker piece of angle stock, since there isn’t as much of it in contact with the baffle. Not shown in this photo is the small piece of angle on the front edge of the baffle, which provides enough beef to keep everything solid. You can also see the conical gusset clecoed into place. This is an interesting bit of business, because the aft-most hole on the conical gusset goes through the inlet ramp and the bend in the side baffle. The two forward most holes are done with flush rivets so the airseal material can lay flat against the surfaces.

From time to time, it’s necessary to put the lower cowl on to check fit and lineup. In this shot, you can see a slight conflict between the aft platenut on the cowl and the forward edge of the baffle. Trimming away a small bit of the baffle fixed this.

This is another view. The aft angle piece took care of the gap between the baffle and the inlet ramp frame, but there’s still a small one on the first bend. This is why the archengineers of aerospace spec’d out high-temp RTV.

Back to the left side. It’s a little hard to see, but there are four flush screws holding the front baffle to the angle from earlier, which is riveted to the inlet ramp.

Here, everything is screwed on and riveted, except for where the two upper baffles join. I’ll have to fabricate a bracket that will connect to the case bolt just above the governor drive gear. Sorry for the blur. the iPhone 3g has some issues compensating for the light levels present in my shop during daylight hours.

The next phase of this is to cut down the top edges of the baffles to allow the top cowl to be installed. This is another iterative, bit-by-bit process, taking care not to remove too much metal, but enough to allow the cowl to sit where it’s supposed to with the hinge pins installed.

As you can see from this photo, there’s plenty of metal that needs to go away before the top cowl will sit where it’s supposed to.

I started the rough cut, and rough is definitely the word for it, but the idea is to get the cowl to fit again. There isn’t too much reference for this step, in the plans or on the Interwebs, But it becomes obvious what to do after a while. There was a lot of anxiety reaching this point; nothing on this up to now has been simple or easy, why should this be any different? But eventually, you just need to sack up and start trimming the baffles.

Just check for fit frequently.

After this is done, you’ll need to make the final trim, which is 1/2″ of clearance between the top edge of the baffles to the cowl, uniformly, all the way around. There are various methods for doing this, although I foresee a little more chicken-and-egg when it comes time to do the upper inlet ramps, which are fiberglass, and attached to the top cowl. I’ve decided I’m going to cut down the side baffles to fit the upper inlet ramps rather than having them ride outside of them, as some have done. I think this will provide a better seal and reduce the amount of dependency on interlocking parts.

Mostly the process involves deriving a reference line on the baffles to use as a cut guide. Some have done it with paper clips: put a crap-ton of paper clips on the baffles and the cowl pushes them down and lets you mark along the contour. Also there’s the wheel-and-sharpie method, where you cut the end off a fine-point sharpie and put a 1″ disk of aluminum on the felt tip, rolling that along the contour of the cowl to mark the line, although I don’t see that working real well except for anyone besides Plastic Man or an octopus, given the space constraints you have for arms and hands.

Today and yesterday.

My motivation this week was at an all-time low, and the anxiety factor was at an all time high. Some of these tasks that look like nothing turn out to be major headaches. I’m currently working on the forward baffles, and there is no way this could have gone smoothly. This front-governor nonsense has proved itself to be a recurring pain, and fitting the O-540 baffle elements to the O-360 kit is a pain.

But yesterday I sucked it up and made attach brackets for the left front baffle. This is hard, because the angle has to match the inlet ramp and the baffle at the same time. I got it done though, and put a bunch of platenuts in it so I can detach the baffle from the inlet ramp to facilitate working with the prop governor. It should work OK, but it bears watching. I also riveted the inlet ramp and baffles together, where applicable, plus set up the air dam that attaches to the main angle bracket of the left front baffle. Fortunately on VAF, there was a post about putting this on with platenuts, because it will probably need to be shaped a little during flight testing to adjust cooling properties. I also finished the snorkel/inlet ramp interface, and bent the leading edge of the inlet ramp down to serve as a barrier for the air filter. It all works.

With the exception of one of the brackets, and the sealing of the area around the corners of the snorkel intake, the left front baffles are done.

Today I worked on the right front baffle. I drilled in the conical gusset, plus the air dam got the same platenut treatment, and I started fabricating the bracket setup for the front baffle/inlet ramp connection. There’s no governor to get in my way, but the retention system is different, so I have to fab a couple of brackets for it. I did one, but I need to do two more. I might be able to finish that up tomorrow.

The goal is to get the baffles in a state where I can start cutting them down to fit the cowl. After that, it’s plumbing, cabling and wiring.

I took Friday off to build. I take every other friday off to build, since I’ve got the vacation days, and Friday/yesterday were big build days.

This section is a lot of problems to solve, all interwoven and tangled. I had hoped to be finished with the snorkel this weekend, and I got pretty dang close. I got the filter mounts riveted to the snorkel, then got them drilled to the baffle. It was a little more complicated than that, but mostly just iterations of measuring, cutting a little, measuring, repeat. Now all that’s left of that is to dimple the screw holes on the filter mounts and install the platenuts.

It was during this process that I started the iterations on making the front baffles fit. Since my engine has a front-mounted governor, I bought a set (and an extra set) of the front baffles for the RV-10. I was able to cut them down to match the -7′s lower inlet ramp angle, and went through numerous iterations of grinding to get the contour right. The left one should fit the governor just fine, and the angle matches the inlet ramp perfectly. The right one might need a little work, but I have an extra one and I can use the current one as a template if I have to.

As if that wasn’t enough to make things interesting, I get to figure out how to install the top cowl inlet ramps in such a way that glassing them in won’t result in a hinge misalignment. The manual says (one of the few things the manual says about this area) to install the ramps with the top cowl on. Well, that’s just great. How the hell am I supposed to fiberglass that? Maybe drilling/clecoing for initial position, then glass it with the clecos still in, holding it together. In any event, all the baffling will have to come off before this happens.

I’m also going to have to order a new batch of Proseal to finish off the air filter mounts.

The baffles are going to need lots of trimming. A quick test fit shows the top cowl being not even close.

Yesterday and today. I’ve been blowing this off, mainly because there was no good time to spew fiberglass dust all over myself, and the fact that I accidentally sheared off the cord of my Dremel tool with the fiberglass bit last time. The sparks were epic. Yes, that was stupid. So yesterday I went to Home Despot and picked up a new Dremel 4000, and this time, I got the flex-cable attachment that lets me use the thing a lot more like a pencil or some other fine instrument.

I tried to take a lot of pics, because the process of fitting the VA-132-1 snorkel to the AFP FM-200 fuel controller and the front inlet ramp is a complete and total whore. Hopefully my documentation can help somebody have less of a ride thorugh hell. There is very little in the way of direction in the plans that actually provides useful information. About the only thing I needed the plans for was to tell me which side of the snorkel the filter mount flanges go on. It’s the inside, in case you’re curious. Oh, and the reference photos on the plans are terrible, and there aren’t enough of them to give you any in-depth information as to how things are supposed to fit. Yes, I get that there should be a big square hole in the front inlet ramp that should have an air filter under it. All aboard the NS Sherlock. Even so, fitting it to the AFP fuel controller brings with it its own set of travails, which is largely the root of the issue. Now, the FM-150, released the year after I got mine, has a square flange on it, like the Bendix or Precision Silverhawk servo, which means the snorkel will fit a lot better. Too late for yours truly, however.

So today, I was determined to make the filter mounts and mash up the parts necessary to make the filter fit.

This was the state of affairs after trimming the snorkel to match the contour of the inlet ramp, bend and all. This was a tweaky, iterative process, the first of many. With the snorkel attached to the fuel servo (throttle body), I had to trim away millimeters of material until it was kinda sorta flush with the contour of the inlet ramp, including the bend in the material designed to match the contour of the cowl opening.

With this in place, I was able to trace the shape of the snorkel opening onto the bottom of the inlet ramp.

View from the top, before anything was cut. At this point, I’m test-fitting the filter retainer, which is going to connect to the whole apparatus by way of #6 screws.

I gave myself plenty of room to work. The initial cutout for the opening was about 3/8″ inward from the actual edge. I wanted to make sure things could shift around a bit when installing the W-sections that would become the filter mounts.

First step was the aft side, which is the hardest, because there’s a joggle downward from the angle attached to the cylinders and block to the actual ramp. This means that the W-section of metal designed to accommodate the filter needs to fit in there, and match the angle of the snorkel’s surface. This was not easy, and I think I’ve got enough edge distance to get by, but I’m not altogether sure.

So after cutting away a good amount of the flange on the filter mount, and bending the metal to match the angles, I got a pretty decent fit. Here, you can see the metal flange through the fiberglass, with positions marked for where the rivet holes are going to go. It was at this point I figured I should take a look at the drawings, useless as they are, to make sure I wasn’t committing an obvious error.

Once this one was nailed down, everything stopped moving, and it was much easier to work with the whole assembly with it anchored at both the servo end and the filter end. Good thing I checked the plans. As mentioned before, the flange goes on the INSIDE of the snorkel chamber, not like it is in the previous photo. Fortunately, there was enough give to let me squidge the snorkel back enough to make this work. But blocking it out like this gave me a perfect reference as to where to cut down the snorkel to clear the joggle on the W-section.

The next filter mount section was relatively easy. Too bad I cut the W-section too short with the bandsaw. Stupid muscle memory. I thought about it, I double checked it, I marked it, but I wound up cutting it too short anyway. Not a big deal, I have a template now, and I know how it’s supposed to go. Replacing it will be simple. The next step beyond the filter mounts will be opening up that inital cut to clear the horizontal part of the filter mounts. The idea is that the air filter rests on the joggle in the W-sections, but the forward lip of the filter just slides in under the opening.

To get the outboard one, I had to shave down the filter mount flange at a slight angle. I also finally had to bend the lower flange on the outboard baffle to match up with the inlet ramp. But this actually made things easier. Plenty of edge distance, and the third filter mount went on no problem.

A closer look at the outboard filter mount, from the front. The little piece of metal that looks like a ‘J’ is the horizontal part of the W-section where the filter lip rests. The snorkel will still have to be trimmed up front to allow the lip to clear. Probably should have photographed the filter a little. I will next time.

So that was the scary bit. I had no desire to start anew with a new snorkel (which is pricey), and other than the inboard filter mount, I don’t have to order new parts. It’s an iterative tweakfest, but eventually, things stop being awkward and you can actually get some stuff done. Just to make sure I wasn’t crazy, I put the lower cowl on, and everything seems to clear just fine, but the cowl will require a little bit of trimming.

Next is to enlarge the filter opening and make the filter retainers, and install the K-1000-6 platenuts that hold the whole thing together. Once that’s done, I can finish the front baffles, which are going to be interesting on their own.

Short day today. This morning was an Easter Egg hunt and brunch, so I didn’t get going until about 1 or 2. My setup for glassing the opening ring of the snorkel worked great, but the resin adhered to the demoisturizer container/plug a little too well. It cracked the container when I wrenched it out of there, but it didn’t make a huge mess. I spent some time sanding down the inside of the snorkel to smooth out the bumps, and it seems like it’ll work OK.

I did get the snorkel on in preparation for trimming the filter end to fit the contour of the inlet ramp, with its bent-up section as called out in the plans. I’ll post some photos later, but the main issue is one of reference. To get the snorkel on in its pre-trimmed state, the inlet ramp needs to come off. But then there’s no reference to where the inlet ramp is actually going to be. fortunately, I marked on the side baffles and the engine where the inlet ramp fits, and through the use of cleco clamps, angles, and a steel ruler, was able to transfer those references to the snorkel. It’s going to be hard, and it will take some iteration, so the key will be not trimming away too much of the snorkel during the fitting process. However, if that does happen, it won’t be a total disaster, I can always cut away enough to make absolutely sure it clears, then extend it to the baffle using new fiberglass, and doing that will insure that it absolutely conforms to the inlet ramp shape.

Today I did some more work on the snorkel, this time trying to shape the throttle body side to allow for smoother airflow, fill in some voids in the opening, and generally beef the thing up where the interface is.

This is looking into the relief hole I made for the alternator. You can see that the demoisturizer container serves as a perfect plug in place of the throttle body and the tape wrapped around it is exactly where the lip on the TB would be. The dark bit on the right inside the hole there is a void that didn’t get filled on the last glassing pass. I roughed up everything, cleaned it out, and went to town.

This is looking in from the top, where the air filter will go. It looks pretty anatomical, I know. The thing I have to fix now is where the opening bulges up, which will create a turbulent airflow.

Weapons of the trade. That’s the Builder Shield plastic on the left, and West System 206/105 epoxy resin on the right with the pumps sticking out. Living 3 miles from Marina Del Rey, I’m fortunate to have a West Marine store where I can buy this stuff. I wanted to get the 206 hardener, because I needed more pot life from the epoxy. I can wait the 10-15 hours for it to cure.

The photos stop for a bit, because of the whole resin/iPhone thing again. The next step was mixing up a bunch of micro to fill in some voids and take a crack at shaping a more gradual transition inside the snorkel where that burble was going to be. The first thing to figure out was how to fill in the voids around the actual opening itself. What I wound up doing was fairly genius (assuming it comes apart properly tomorrow). I wet down a strip of glass cloth, put it on the inside of the opening ring, then jammed the plug through it. It should form a perfect shape around the plug, and I can easily cut/sand off the excess on either side.

Here, it’s about done. There’s micro in there, and a couple of layups of glass around the burble and the rest of the edges go hold everything down. I also put a couple more layups on the outside to thicken up the interface ring.

With that curing, I went hunter-killer on some of the smaller items that I’ve been blowing off. First thing was reclocking the prop governor cable bracket.

This bracket also goes on the IO-540 in the RV-10, but the -7′s cowl doesn’t have enough clearance to let that happen. I’ve seen one or two examples of putting a bump in the cowl to allow the bracket to clear, but since I want to do as little fiberglass as possible, I decided to reclock the bracket. That just involves drilling two offset holes. The bracket will stay on just fine with two screws. I didn’t need to do much, that’s maybe a quarter-inch of distance between those hole, but I managed to bring the end of the arm down enough to where there won’t be any interference issues with either the cowl or the #2 injector line.

Since it’s time to think about things like control cable and wire routing, I decided I should probably put the exhaust system back on. The more things that are actually on the airplane, the fewer guesses I’ll have to take when deciding where to run things. Forward of the firewall, the name of the game is keeping things from picking up too much heat, and the primary source of that is the exhaust. The recommended distance between the exhaust and anything else is half an inch. Anything comes closer than that, and it needs to be shielded.

What you see here is the 4-pipe Vetterman exhaust I had to purchase to replace the crossover 4-into-2 type I had before. With the Crossover exhaust, there’s absolutely no way to get control cables to the throttle body without a horribly complex series of bellcranks and other things I really don’t want to mess with. The 4-pipe setup has a nice wide space up the middle where I can route the mixture and throttle cables without getting them too close to the pipes.

Since the right aft baffle is already on the engine, and finished enough to matter, I thought it might be a good idea to get the two-pipe cabin heat muff set up, along with the suspension by which the aft sections of the pipes hang. I’ll admit, I can’t find the instructions or drawings right now, but it really only makes sense to put it together one way. This is all about making sure I have all the parts, which I do, except one of the nuts is defective. There are no threads in it. I don’t even know what that type of fastener is called, to be honest, so I’m going to tap it for whatever threads the connecting rods between the brackets are. Like the crossover version, the pipes hang from stainless steel tubes connected by sections of rubber oil hose, so that’s no mystery. But with this and the baffle in place, I’ll be able to hook up the cabin heat system.

Saturday and Sunday. The snorkel fit fine with no modifications. April Fool’s! Seriously, this thing is the biggest POS in the whole inventory. There’s no way it will fit without mods, ever. It doesn’t even fit well with the engine Van’s sells. It is a black hole of suck, no two ways about it. Firstly, I hate fiberglass. Second, I have the AFP fuel injection system. Third, this thing has to line up in at least three places before it can be said to ‘fit.’ Let’s have a look.

What you see here is an attempt to make a plug in the shape of the throttle body intake. To do this, I make a ring out of .032 aluminum, then riveted it to another ring just inside that one, with the shop heads sticking out. This slipped over the throttle body intake and the idea was that I’d tape it off, fill it with spray foam, and have a perfect foam plug from which to form all my fiberglass and use as a sanding block later. No such luck. The foam can I used had probably been sitting on the shelf for about 6 years or so, and never quite cured. Mess. And before you ask, yes, I taped up the throttle body so no goo would get down inside. Back to square 1.

I don’t have a lot of pics of the snorkel in its totally hacked up form, because I didn’t want to get fiberglass dust all over my phone. Basically, I had cut away pretty much everything near the flange of the snorkel, leaving a hole big enough to get the throttle body into. A lot of people cut the snorkel in half and re-glass it back together after fitting each half, but I didn’t want to do that, for some reason. Since I was committed to glassing a whole new flange on it, I didn’t see the need to cut it in half. So that led to the next process:

When fitting this thing, not only does it have to line up on the throttle body intake, the filter end has to line up on the left front inlet ramp, and it has to do it while clearing the #2 oil line, the governor baffle, and the front side baffle. Plus there needs to be enough meat around the edge of the air filter hole to attach the supports and meet any riveting edge distance requirements involved. The only way to get it into position is to take off the inlet ramp and try to fit it that way. surprisingly enough, this does work. I wound up suspending the snorkel in a cat’s cradle of PVC pipe tape (all hail pvc pipe tape, that sh*t rocks!) in the position it would eventually be in once everything is glassed and cut.

I also found my new best friend for fiberglass work: Contractor’s carpet guard. This stuff comes on a roll like Saran Wrap, and it’s the stuff contractors lay down on your carpet before they start trudging in with muddy boots and taking out old sewer pipes. It has a mildly adhesive backing, and it clings to itself and smooth surfaces like crazy. Think of the blue stuff that comes with Van’s kit parts, but clear. It leaves no residue behind either, although they do recommend you don’t leave it on for more than 30 days. Anyway, this stuff became the new throttle body condom, as well as a wrapper for anything else I didn’t want to get stray resin on. I took the alternator off, because it was seriously in the way, but I just wrapped a bit of this stuff around the starter and the alternator bracket. Oh and all over the throttle body. Like so:

Here’s a mostly side-on shot of the opening in the snorkel next to the throttle body. As you can see, it’s not even close. But with the TB protected, I can slap glass on this thing until the cows come home.

From the back.

Now the photos stop, because I’m not about to get resin all over my phone. I used two layups of the same stuff I had when I did the canopy. I’ve got a crap-ton of it left, wo a few pieces got me through. I was able to make a decent connection between the TB and the snorkel, the end result of which is this:

A perfectly-shaped snorkel-to-throttle-body interface. OK, not perfectly shaped, but close enough to keep going. This is after 8 hours of cure. There are some voids where the plastic wrinkled around the throttle body opening, but that’ll get fixed in the next couple of days or so. I did find a perfect facsimile for the throttle body opening though. At the hardware store, they sell this demoisturizing stuff. It’s basically little balls of salt, but what’s of interest to me is the container. The container is smooth plastic, and it’s exactly 3.25″ in diameter, same as the throttle body. Half an inch up from the bottom, I wrapped about 1/8″ thickness worth of pipe tape around it to simulate the lip of the TB, and I was able to use that as a plug for the next 3 layups of reinforcement of the opening.

The inside is a different story. I’m going to be in there with micro, shaping a smooth guide for the airflow around the parts that indent too far into the snorkel chamber and will cause turbulence rounding the corner into the throttle body. That’s when I squidge some micro between the plug and the interface there to fill the voids as well.

See, this is an interlocking puzzle, kind of like a Rubik’s Cube, but none of the pieces are square and there’s no colors to tell you when it’s right. You just need to end up with a shape that meets certain requirements, i.e. everything fits without rubbing on something else and nothing makes the prop stop spinning.

First thing to do: Clean the shop. I swear, sometimes I don’t even know why I bother having a tool box. Everything winds up strewn all over the place anyway. It’s reboot time, because when something I’m looking for is buried under crap I should have put away and it takes me 10 minutes to find it, it’s time to fix that.

So, the baffles:

1. Order new front left inlet ramp. This is because I may have already trimmed too much off the front edge to get the thing to fit inside the cowl. Have to check. I can still use the old one for lineup and getting the shape right, but there might not be enough meat on the front of it to brace the air filter.

2. Make the bracket that connects the ramp to the engine. With this in place, I’m not trying to hit a moving target as far as shaping the opening of the fiberglass snorkel/airbox, and also the angle of the front upper baffle that goes around the prop governor. OBTAIN PROPER BOLTS FOR BRACKET. Big, meaty 3/8″ Grade 8 bolts that connect to the pad just below the governor.

3. Find the rest of the airbox kit, especially the W-channels thqt hold the filter in place. I know they’re in there somewhere, I just have a filing system for parts that closely resembles the Sargasso Sea.

4. Make a collar for the opening of the fuel servo’s intake to assist in fitting/trimming the snorkel. Yeah, that should have FA to do with the baffles, but like I said, it’s an interlocking puzzle. The takeaway from this is that sorting out the snorkel before cutting any holes in the baffle means there’s no need to cut the snorkel in half and re-glass it.

5. Cut/grind off the extra ears on the starter so they don’t interfere with the snorkel.

6. Cut a relief into the snorkel so it clears the alternator bracket. This is a common mod. Why Van’s sells a part that doesn’t work out of the box with 90% of installations is a mystery to me.

7. Maybe not actual step 7, but finish the conical gusset, trimming, and fastening for the right-hand side, which seems to be working OK.

8. Glass in the top cowl inlet ramps. These will be necessary for the next step.

9. Begin the iterative process of trimming the top sides of all baffles down so the top cowl fits and the baffle seal strips will seal.

Continuing work on the front left inlet ramp. I had to puzzle some stuff out, because this one is a little different from the right side. On the right side, bending the inlet ramp at an angle lines it up to the cowl inlet pretty well. On the left side, you need a big flat spot for the air filter. Also, the amount of crazy you get to deal with when it comes time for the filtered air box is directly proportional to how well you line up the hole in the inlet ramp for the air filter.

Tonight I cut the big stupid flange off the FAB to make the opening somewhat resemble the AFP fuel servo intake. It’s still not even close, but it’s probably wide enough, there will be more trimming. I’ll also have to do two things: Cut a relief hole in it for the alternator bracket (why this isn’t in there from the get-go is beyond me), and grind off one of the ears on the starter. When that happens, I’ve got a fighting chance of lining up the FAB where it’s supposed to go on the inlet ramp.

The other thing about the left inlet ramp is that I have to fabricate the inboard bracket that attaches it to the engine. Fortunately there’s a big square pad with two 3/8″ threaded holes exactly where I need them to be to mount a support bracket for the inlet ramp. After some diggin on VAF and around the internets, I’ve found that even with the bend in the inlet ramp, the filter will still fit, because it’ll flex around the bend. Then the FAB just has to be trimmed to accommodate the shape, and it’s on.

Yesterday and today. I’ve been dreading this, mostly because the baffles are, uh, baffling. But with the cowl halves fit, it was time to seriously tuck into these things. Friday, I got a present from American Propeller, my new PCU5000x. I think they put the wrong spring on it, because the spring returns the control lever to the low-rpm position, but that’s no biggie, they can send me a new one. Either that or I pooched the order, which would suck, but it’s not a showstopper, I’ll just have to run the cable up from the bottom.

It’s a lot less bulky than the old McCauley that was on there originally, although I might have to reclock the bracket to clear the cowl. This is done by drilling a couple of offset holes in the bracket.

Yesterday, I farted around with the baffles for a while, putting them on in preparation for cutting the front ones to the cowl. I figured I’d be fancy with it this time and make some cardboard templates to get the shape right. This didn’t work out all that well. My plan to set it up like Bill Wightman’s installation didn’t work at all, because I couldn’t for the life of me transfer the shape of the governor pad onto the cardboard with any degree of satisfaction.

It seems simple enough, but it’s not, and I couldn’t quite make it work.

What I wound up doing was using the IO-540 baffles from the RV10 kit I’d ordered a while back. For some reason, this option dropped almost right into place. I had to modify the right side baffle to match the angle of the inlet ramp, but that worked out pretty well, once I actually figured out a good way to measure and cut it. The left front worked out fine, since the pre-cut hole was actually designed for a governor the size of the PCU5000X.

Today’s efforts consisted mostly of putting the bottom cowl on and taking it off again. A lot. I trimmed the front side baffles to clear the cowl, then worked on getting the proper shape for the right side.

This is the left front trimmed back enough to clear the cowl and nest in the spot just outboard of the cowl inlet.

Cutting the shapes was actually easier than I thought it would be. There’s a lot of extra metal on the front inlet ramps, maybe these things are designed to work with a variety of configurations, but the basic deal is that you have to trim everything so it tapers down to the rough opening of the cowl inlet. It takes several iterations.

Once you have the basic trimming done, the front inlet ramp comes off and you have to bend it along a line that starts at the point where the cowl inlet edge is tangent to the ramp surface and ends up in the corner where the front side baffle and inlet ramp connect. The bend brings the front ramp roughly into line with the inlet.

Like so. There’s still more trimming to be done, because the way this works is that a strip of baffle seal material goes around the pink bit and seals against the ramp and sides. On the right hand side of frame is the 540 front baffle. I’m not promising this is going to work, but it seems to fit OK., and if it doesn’t, I can use it as a template to cut on one of the spare 360 baffles I ordered from Van’s just in case.

Also a conical gusset goes in the corner where my fingers are, one that more or less matches the shape of the inlet. This does two things, it gives a better seal under pressure and stiffens the structure where the air comes in.

After that’s all done comes the fun part: Trimming the upper edges all around to match the contours of the top cowl.