Project Update

Hi Folks,

Yep, the internal CF baffles and aluminum baffle walls are installed, and I’m now working to finish up the perimeter baffle seals… in the shortest order possible.

I had noted previously that all the exhaust pipes have been welded, but after assessing the inside-cowling positioning I need to angle both left side pipes further inboard… this will require recutting and rewelding the outboard left exhaust pipe.  Once the outboard left exhaust pipe is situated, I’ll get to trimming all the exhaust pipes to final length. 

After a few months off due to cold weather, some house projects and getting engaged, I’m still intent to focus solely on the plane for the next however long it takes to finish this bird… ASAP!  

Chapter 23 – Right baffle seals installed

Today was all about finalizing the aft right corner vertical baffle seals install, and I’m happy to report that I was able to finish that task.

After determining the shape with a paper template, I started off by cutting the top corner aft right baffle seal and fitting it into place, replete with rivet holes drilled and punched.

Here’s the temp install of the aft top right vertical baffle seal segment, held in place by the new and improved 1/16″ thick 2024 angle reinforcement corner bracket (pic #1).  I then mounted the top cowl to test fit the new baffle seal segment (pic #2).  The fit was good and other than trimming down the width a bit, I had no other issues.

The next lower corner baffle seal segment was a little bit trickier, and it took a good number of iterations, both in paper templates and with real actual baffle seal material to get this piece dialed in.

After a few rounds of top cowl on and off, and 2 baffle material segments before finally hitting the configuration jackpot on the 3rd (IIRC), I finally got it dialed in.

As for baffle seals, the final segment was the inboard piece that creates a split seam with the corner piece above to allow for the upper cowl’s right #2 CAMLOC to slide in and out of place when installing or removing the cowling.  In this pic you can see blue painters tape which is what I used for a few rounds of the initial template.

Sitting just inboard of the baffle seal blue tape template is a short piece of angled 2024, which is getting installed in the inside corner to both reinforce the aft right corner, but also provide some meat for the upper outboard K1000-3 platenut that will secure the top exhaust pipe bracket in the upper right corner (I did the same on the left side).

Here we have the aft left inside bracket installed (on the inside corner held in place with the rivet facing aft).  Also note by the copper colored clecos that I drilled out the rivet holes to their final 1/8″ diameter.

After another 45 minutes of cutting and testing the inboard baffle seal segment (blue tape guy from above) I then got to gooping (Hi-temp RTV) and riveting the aft right vertical corner baffle seals into place.

A shot from the inside.

And a shot from right aft outboard.

And a shot from the front “business” side showing the rivet backs and reinforcement bracket.

Yes, it’s a bit of an odd configuration, but here you can see the right side bottom exhaust pipe bracket (mockup) outboard attachment tab secured by a screw, overlaying the bottom inboard baffle seal segment.

And a final shot of the top left exhaust pipe bracket cardboard mockup.

Tomorrow I plan on getting MOST of the aft baffle skirt’s bottom edge baffle seals cut and installed.  However, there will be baffle seals that attach to the bottom edge of the bottom exhaust pipe brackets on each side, so until I get those stainless steel brackets cut out, configured and welded up the baffle seals will not be officially completed.

That being said, I’m pressing onward!

Chapter 23 – Right exhaust pipe tab

Today was all about getting the aft right side baffle seal reinforcement angle strip configuration finalized and installed (the install part didn’t happen)… along with the baffle seals that it will help secure.

Here is the original right side baffle seal reinforcement angle strip (blue) held in place with a clothesline pin.  Note there is very little peaking out on the bottom from behind the actual aluminum vertical baffle wall.  There are 2 reasons for this: A) I was using a length of 0.032″ 2024 that I had leftover from the VANs baffle kit and this length was all I had remaining after cutting out the left side, and B) I had intended to simply copy the bottom edge of the baffle wall to allow for clearance of the #2 CAMLOC while mounting the top cowling.

However, after assessing the aft right baffle corner with the requirements on how the right side exhaust pipe brackets will get secured, I simply didn’t have enough clearance with the right outboard exhaust pipe (from cylinder #4) to make an inward facing tab, as I did on the left.  The tab would have to face outward, so I decided to create a wedge just below the existing vertical baffle wall using the right side baffle seal reinforcement angle strip.  Clearly since the original angle reinforcement strip doesn’t hang below and isn’t long enough, I needed a new one.

After scrounging around I found this length of 1/16″ 2024.  A little thicker than I was looking for, but definitely not too crazy thick.  I temporarily secured it in place to check if the length was good.  It was.

I transferred the outline of the original right side baffle seal reinforcement angle strip to this new stock and then cut out what I could on the band saw.

And finished up some the trickier corner cuts using my Dremel tool.  Here we have the old right side baffle seal reinforcement angle strip along the newly made one.

Again, I did a quick test fit and it looked like it was definitely going to fit the bill in regards to my new requirement.

Somewhat as I did on the left side, and after a few rounds of assessing the aft right corner’s configuration, I mounted a 10-32 platenut to the right side baffle seal reinforcement angle strip onto the bottom edge peaking out from below the vertical baffle wall.

To confirm how the right side exhaust pipe brackets would fit before I proceeded further, I spent the rest of the evening painstakingly and iteratively creating first the bottom bracket, replete with its outboard mounting screw hole (pic #2).

I then did the same thing for the top side, making up the mounting bracket mockup in thin cardboard.

I’ll note that I of course reserve the right to change the design of the top side bracket, in that it looks a little round on the corners to my liking… perhaps I’ll try to match it more with the left side, still allowing for the exhaust pipe clearance opening in the baffle underneath.

Tomorrow is shaking out to be a rather busy day.  I have an EAA meeting in the morning, multiple scheduled phone calls, etc.  but hopefully I can get out into the shop to knock a good bit out.

Chapter 23 – Left baffle seals installed

Today was all about getting the aft left baffle seals installed and done with.  After remaking the larger lower baffle seal segment to extend it outboard, I then redrilled all the rivet holes out to 1/8″.  I also pulled the blue protective plastic off the aluminum parts (all 0.032″ 2024 aluminum scraps from the VANs Baffle Kit) and cleaned those up with acetone before gooping up the baffle seal edges with hi-temp RTV and riveting them into place.

Another shot of the aft left baffle seals installed.

And yet another shot from the forward side.

To do a final check on the aft left baffle seals fit I mounted the top and bottom cowlings, after I secured the exhaust pipes into position with some string… since I noticed that tape wasn’t holding them in place well enough.

I also did another round of sanding and shaping of the top cowl’s aft right trailing edge intersection with the right wing’s TE.

Here we have the installed aft left baffle seals inside the cowlings.  I’m thinking this dog will hunt!  I do see where I may have to pull the very bottom baffle seal into place aft of the CAMLOC, but that may very well be remedied just by putting the top cowl on first and then the bottom cowl on after that, whenever able.

A shot of the left side cowl opening with both the aft left baffle seals installed and the exhaust pipes (note still not finally trimmed to length) secured in position as well.

Here we have a couple of shots of the right side exhaust pipes (also not trimmed to final length) set close to final position inside the cowlings.  I’ll be starting on the aft right baffle seals next.

Moving forward!

Chapter 23 – Left aft baffle seals

Today I started off by cutting out a quick rough mockup of the topside plate for the left exhaust pipes’ securing bracket.  I’ll fine tune it and dial it in as I get closer to actually constructing the bracket.

Here are a couple more shots of the left side exhaust pipe bracket mockup.

I then embarked on the slow arduous process of cutting out templates (here I’m using a paper towel) for the aft left corner baffle seals…

Then placing the baffle seals, drilling the rivet holes, and test fitting the baffle seal segments.

Once I was sold on the baffle seal fit —this is just the top aft corner seal— I would punch the rivet holes in the baffle seals with a leather punch.  These oversized holes allow for more movement of the seal and reportedly mitigates the seals from splitting due to vibration.

Again, the machinations of fitting the baffle seal segments to the aluminum baffle, as well as integrating them to each other, then checking if they close up the gaps with the top cowling installed, is a very iterative process: with cowls constantly going on and coming off, with nearly all the CAMLOCs installed to check final baffle seal vs cowl contour.

That all being said, here I’m checking the clearance of the #2 CAMLOC of the top cowling with the bottom of the aft left corner angle reinforcement strip (blue, red pointer) that is hanging down below the aluminum baffle corner.

Although the reinforcement strip didn’t really create any clearance issues, I trimmed it at an angle to match the contour of the top cowl’s interior lip, and then cut, shaped and created another fascia piece to cover what would be exposed baffle seal material down in that lower corner.  Clearly it also helps reinforce the 2 overlapping baffle segments down in this corner.

Here we have all the aft left corner baffle seals in place, minus one small segment (see next pic).  The V-shaped gap on the side is to allow the baffle seals to seal both above and below the oil door opening cable conduit, respectively.

I then once again mounted the top cowling to double check my work.  As an added layer to seal up any gaps allowing any air through or around the oil door opening cable conduit, the small baffle seal segment (with green tape and red pointer) will be mounted on the forward side of the V-shaped split, filling in that gap.

It was quite late and although I didn’t reach my goal of actually getting the aft left corner baffle seals installed, I thought better of pressing forward tonight in order to ensure that I could double-check my work tomorrow in that all air paths are blocked off.

I’ll add that I ended the evening by taking a good look at my bottom spark plug wires’ routing as well as the EGT cable routing.  I’ve got a good mental plan on how I want those run and will document some mounting tabs that I’ll need to make up.

Speaking of EGTs… Yesterday I installed first the standard EGT probe into the cylinder #2 exhaust pipe and assessed its clearance.  It was quite acceptable (clearly not quite as good as if I used the compression fitting EGT probe).  Today I did the same on cylinder #3.  Same story.  So my plan on EGT probes AT THIS TIME is to use all standard probes and upgrade when able (task complete… for now!).

Pressing forward…. painstakingly slow at this point!


Chapter 23 – Left exhaust pipe tab

Yesterday I used a yard stick with a Sharpie taped onto the end of it to make a mark on the top cowling right baffle & reinforcement rib as a starting point for where it needed some trimming.

Today, after removing the top cowling, I started at that mark going forward to mark the right baffle rib for trimming (pic #1), and then trimmed it (pic #2).

After re-taping the outboard left exhaust pipe back into its proper position, and the left lower outboard exhaust pipe bracket mounting tab, I then mounted the top cowling back into place.

I have to say trimming the right baffle rib seems to have done the trick as all the front right corner fasteners went in fairly easily.  Moreover, the baffle seals are slowly conforming to the shape of the top cowling as each time the top cowling is mounted in place it’s going on just a little bit easier each time.

I also took a few minutes to sand down the outboard trailing edge of the right aft side of the top cowling where it intersects the aft inboard TE of the right wing, of which I’ve also been doing some fine tuning as well (marking while cowl on, then sanding/trimming when top cowl off).  I still need to finalize the cowl TE here, but I’m waiting until all the baffle seals are in and the exhaust pipes are secured internally to finalize this junction.

Of course the left outboard exhaust pipe hasn’t been welded up into it’s final configuration yet, nor have the exhaust pipes been trimmed to final length, but here is a current view of how they sit inside the aft left opening of the cowling.  Not bad, but they do tend to still point outboard a bit more than I want.  I’ll try to mitigate that a bit when I trim them to final length inside the cowling.

I thought I would add a shot of my chicken scratching plan that I drew up last night for today.  Of course while my mental meanderings can take a bit of time to get down on paper, I don’t often make it a practice to include them into these blog posts.

Now, my primary reason for putting the top cowling back on was to check the position of the left lower outboard exhaust pipe bracket mounting tab that is the focus of today’s efforts.  I had measured the proposed exposed drop of this tab to be 0.875″ from the bottom edge of the current aluminum baffle (“skirt”).

However, after both cowls were installed I realized that this measurement needed to be reduced in dropdown depth to just 0.6″.

With that bit of knowledge I then created the actual outboard tab/bracket (still blue at this point) and taped it into place inside the aluminum baffle aft corner.

I then connected the outboard 0.6″ marked line to the inboard bottom curved line of the bottom baffle edge (inboard of the inboard exhaust pipe) to get my downward angle of the tab going inboard.  I (quite cleverly… ahem!) used a magnet retriever to hold a 10-32 platenut in place to give an idea of what this bracket is all about (pic #1).  I then trimmed the corner tab to length (pic #2).

In a way installing this aft corner tab is atonement for another sin of the past, in that if I had had my exhaust pipe configurations truly dialed in, I wouldn’t have cut nearly as much of the bottom baffle corner away as I did.  Thus, I would have still installed an interior corner reinforcement bracket, but the original face (“skirt”) of the aluminum baffle would have been present.

But since it’s not, I had to resort to cutting out a corner fascia piece of 0.032″ thick 6061 to replace the material I had errantly cut away.  Here we have not only the corner fascia piece fitted and riveted into place, but the 10-32 (“K1000-3”) platenut and the corner exhaust pipe tab/bracket installed as well.

And a closer look at all that…

And a look from the left side at the side bracket securing rivets.

With the exhaust pipe bracket corner tab installed, I remounted the bottom cowling to check clearance… not too bad.

But since the lip of the top cowling overlaps the bottom cowling in this area, I had less than 1/16″ clearance with the top cowling mounted in place.  Clearly some trimming was required.

I reached into the cowling to mark the bottom corner of the exhaust pipe bracket corner tab for trimming (pic #1) and then refined the trim line after I removed both the top and bottom cowlings (pic #2).

I grabbed my trusty Dremel tool and carefully trimmed away the offending extra material on the lower edge of the exhaust pipe bracket corner tab.  I then threw a screw into the platenut just to reiterate the point visually that I installed the darn thing!

It was getting late, but I spent another 15 minutes making up a quick cardboard mockup of the lower left exhaust pipe bracket.  There will of course be a bracket on the top side as well that clamps the exhaust pipes into place on each lower corner of the baffles (with welded-in half tube “cups” compressing the exhaust pipes from top and bottom to secure them in place).

Hopefully this should help explain the purpose of the tab I just installed that will secure the left corner of the lower left exhaust pipe bracket, as there will be a screw securing each corner of the exhaust pipe bracket plates: 2 on the bottom plate (shown) and 2 on the top plate (4 total).  Again, as I casually mentioned, these exhaust pipe brackets are based fairly close to what Mike Melvill had on his bird.

And with that, I called it a night.  Tomorrow, after I finish designing and configuring my exhaust pipe brackets, I intend on getting the left aft baffle seals installed.  I’ll then repeat this process for the right side exhaust pipes and baffle seals.


Chapter 23 – Left pipe redo…

As I mentioned yesterday, I realized that I couldn’t proceed any further on the aft side (“outriggers”) baffle seals install without first getting the outboard left exhaust pipe in its final configuration.  To do that I need a very slight bend or curve near the midpoint around the base of the inboard exhaust pipe to then allow the remaining aft section of the outboard pipe to align and nestle in more closely to the inboard pipe.

Here I’ve marked the removed outboard exhaust pipe (cylinder #3) for cutting into two parts, as well as the scrap curved section that will be getting spliced into the middle section of the current pipe.

I had meant to get a pic of all the component parts after I cut them, but alas I got too wrapped up with getting this thing knocked out… thus it went back on the engine post haste.

You can see by the two respective alignment marks that the very slightly curved middle insert is taped into place.

A few pictures here are only the highlights of the well over 3 hours it took to cut and very carefully dial in the left outboard pipe pieces for both windage and elevation in respect to its own position within the cowlings, and in relation to the inboard left exhaust pipe.  That being said, the end result came out pert near exactly what I wanted/needed: the left outboard exhaust pipe —at the proper elevation— aligned parallel with the left inboard exhaust pipe (note the inboard pipe aligned with its bottom cowl mark).

Of course now I’ll need to get with James for him to work his magic welding kung-fu and get this outboard left exhaust pipe final configuration locked in.

As a comparison, this is what this pair of pipes looked like before my corrective alignment “surgery.”

Also, here is the bottom cowling mini-aft baffle bulkhead with its height trimmed…

And the resulting gap between the bottom cowl mini-aft baffle bulkhead and the bottom edge of the baffle at 0.15″, offset just enough to allow for any clearance required.

With the outboard left exhaust pipe repositioned, I could then focus on the left aft corner baffling.  After taking a myriad of measurements and looking at the situation from just about every angle possible, I developed my plan to allow both the baffling to get installed in this corner, as well as a Melvill-style exhaust-securing bracket that will both close up/seal the baffle gaps around the exhaust pipes and secure them into position.

The initial step to installing the exhaust pipe bracket is to add a piece of aluminum angle (blue in pic) into the lower left corner to mount a K1000-3 platenut that will be one of four securing the exhaust pipe bracket.  I’ll further note that my intention is to get this aft left corner completely knocked out, regarding both baffle installs and exhaust pipe bracket situated, before moving onto the right side.

Moreover, as I was putting the cowlings on and off, I discovered an issue with the top cowl’s right side baffle rib clearance with the engine baffles that caused the seal to get all wonky.  I finally figured out the issue after some investigation and I’ll be trimming down the depth of that baffle rib as well.

Pressing forward…

Chapter 23 – Dialing in baffle seals, etc.

I started out this morning with lots of assessing and planning of the aft side baffle seals.  However, I quickly discovered that I will need to work the exhaust pipes’ brackets before finalizing the configuration of the outboard baffle seals since they all need to integrate together.

Since I needed to assess the exhaust pipes configuration, I then mounted the bottom cowling.  Which also confirmed that the bottom cowling can be mounted with the top cowling in place… the order doesn’t matter.

With the bottom cowling on, I took the opportunity to mark the aft bottom baffle bulkhead for trimming (green tape).

Then, using my alignment mark on the aft edge of the bottom cowling, I set and taped the left inboard exhaust pipe into its position (see last pic below).

After a bit more assessing of the upcoming outboard baffle seals and the exhaust pipe positions, I then pulled the bottom cowling and trimmed the aft baffle bulkhead with my “Fein” saw.

I also pulled the top cowling off, marked the top cowling’s front cross reinforcement and baffle rib before trimming it with the Fein saw as well.

I cleaned up and dialed in the top baffle seals by trimming the aft seal edge on each side as well as punching a relief hole on the inboard side of each slit I made (to flatten out the seals as they’re positioned inside the top cowling).

I then removed the outboard left exhaust pipe and prepped it for cutting it in half (take 2) and resetting it so that it curves in closer and aligns more with the left inboard exhaust pipe.

Chapter 23 – Top side baffle seals

Again, this post covers the last 2 days.  I started by trimming and installing the left side top baffle seals and reinforcement strips.

I then focused on installing the right front side baffle reinforcement strip, first by drilling out the rivet holes (pic #1) and then creating the oval socket extension hole for installing/removing the spark plug in cylinder #4 (pic #2).

I then configured and temp installed the right front baffle seal.

And then set and drilled out the rivet holes on the right aft side baffle reinforcement strip.

After knocking out all the prerequisite prep work, including trimming the top edges of the right side baffle seals, I then gooped up the top baffle seals and riveted them in place with the reinforcement strips.

Here we have the left and right side top baffle seals and reinforcement strips installed.

And another shot of the installed front, left and right side top baffle seals.

After a good bit of getting the baffle seals flipped the correct way, situated and compressed down in proper fashion I was able to get the top cowling fastened into place.

Again, the initial placement of the top cowling with the just-installed baffle seals took a good bit of machinations, but I finally got ‘er on.

My first task was to assess the top cowling front cross baffle and reinforcement rib to see how well it cleared the aluminum baffle wall.  As I could tell by the rivet faces, I’ll be trimming just a bit more of it off so that it clears at least the baffle seal rivets.

After shoving my work light into the engine compartment to light everything up, I then used my trusty inspection mirror to assess the front wall baffle seal.  At every angle I could see it all looked good and firmly pressed up against the inside of the top cowling.

With the pronounced curve of the top cowling on each side —and thus the side baffle walls and seals— I wasn’t surprised to find some bunching up of the side baffle seals.

Here we have the forward side right baffle seal bunched up a good bit.  Near the corner was pretty much corrected by me just smoothing out the baffle, although I will need to trim it a little.

The major wrinkle just above the cylinder rocker cover was remedied by me reaching up with a razor knife and creating a slit until it flattened out.  With pressure on the baffle seal, it wasn’t a perfectly straight cut, but I wanted to do it in situ as to assess the results real time.  I’ll clean up the slit edges when I remove the top cowling.

The left side also had some bunching up both fore (pic #1) and aft (pic #2).

Again, I used a razor knife to cut the slits at the wrinkled seal spots to flatten them out.  And again, not perfect slit edges… but I’ll clean them up after I remove the top cowling.

I’ll reiterate that besides some fairly minor corrective slicing of the baffle seals in a few tactical places, overall I’m very happy with how they’re situated and sealing against the inside of the top cowling.

I called it an early evening to have dinner with Jess.  But before I left the shop, and to help the baffle seals nestle in and conform to the top cowling’s contours, I placed a heated blanket on top of the cowling with a couple of heat lamps shining up from below.  I don’t know how much of an impact this will actually have, since this heat is no way comparable to the heat that the engine will give off while operating, but I figured what the heck… it can’t hurt anything.

Tomorrow I’ll press forward with the lower side and bottom aft baffle seal installs.

Chapter 23 – Front baffle top seals

This post covers both today and yesterday’s efforts on getting the top baffle seals installed.


I started by placing the reinforcement strips along the front baffle wall, determining the spacing of the rivets (most are 1.5″) and then drilling out the rivet holes.  Once the aluminum baffle wall and reinforcement strips were drilled, I then added in the baffle seal, positioned and marked it, and then punched the holes out with a leather punch.

Here we have the front baffle wall left side reinforcement strip secured for rivet hole drilling.

Again, once the rivet holes were drilled through the metal parts, I would fit, trim and add in the top seal segments.

Once the top seals were in place, I trimmed the top edges to somewhat match the curvature of the metal baffle wall edge.  You can see that the just-added right side baffle seal has not been trimmed to shape.


Here we have the front baffle wall top seals installed, with a thin strip of RTV goop applied before the respective segments were riveted into place.

Here are some shots of the “backside” (technically front side) of the just-installed baffle seals.  I’ll note that I’m using “Cowl Saver”™ baffle seals, which claims 10x less friction with the top cowling to save the baffle seals over the long haul.

With the wider diameter head rivets that were supplied in the VANs baffle kit, using my hand riveter was resulting in about a 50% misfire rate when I used it on the lower aft baffle install.  I’ve had this cheaper Harbor Freight pneumatic riveter sitting new & unused in its box for a very long time now, so I broke it out to test it for this task.

After adding WAY too much hydraulic fluid into the reservoir (the instructions are woefully lacking on this key piece of info… as I found out watching a few YouTube videos on this thing!) and making a mess, I finally got it dialed in.  The max rated pressure for this tool is 90 PSI, and I found that 55-65 PSI is the best for setting these rivets.  However, I also found that any added material, as in the an extra baffle plate where they overlap at the engine centerline, it needs the max 90 PSI to prevent a misfire. But I’ll say overall it’s worked a treat.

I then started working on the left side baffle seals, with the main time-consuming task being drilling out the oval 1/2″ wide hole in the forward segment for the spark plug tool access hole.

Another shot of the left side baffle seals current install.

Although not baffle related at all, I figured I would add in this neat little hack of making up a template to fit the prop spinner around the prop (coming up soon!).  It was a canardian posting it on FB in prep for Oshkosh.

I knocked off work early evening to head down to Swansboro with Jess and crew to watch fireworks for an early Independence Day celebration.  Tomorrow too will be a very short work day (if any build work at all) as I have an afternoon party and then will be heading to fellow canardian Guy Williams house for food and fireworks.