Today was all about finishing the trimming, shaping and creation of the top outboard inter-cylinder baffles that I micro’d together last night.

I did a good bit of research today to ensure I knew what the heck I was doing because I wasn’t completely understanding the configuration of these specific baffles, even though Steve Beert sent me another conformational pic.  What was confusing me was why was there no baffle coverage on the fins in between the 2 cylinders?

I went back to Andreas Christou’s document, Design for optimal cooling efficiency, and therein lied the answer!  Things are a bit different from our smaller cousin, the O-235, than they are for O-320/360s… read on:

“The Lycoming O-235-L2C Cylinder head… has less fin depth at the sides, and some attempt has been made to increase cooling on the exhaust valve side of the cylinder. The fin depth next to the exhaust valve is slightly more than on the intake valve side. There is enough fin depth to justify using Bid/RTV baffle material between the cylinders so that the flow of cooling air is divided into two sets of fin tubes. This will distribute more cooling air to the exhaust valve side and will also keep hotter air from the exhaust side from heating up the intake side and consequently raising the temperature of the incoming fuel air charge.”

[Note the red line in between the cylinders denoting a baffle]

Andreas then went on to state this about the O-320/360 motors:

“Placing Bid/RTV baffle material between the fins of the cylinder heads would do more harm than good. Any inter-cylinder baffle material would block the flow of air past the intake side of the cylinder.”

[Note there is NO red line in between the cylinders denoting a baffle]

Eureka!

This would also explain why my buddy Marco found issues on his O-320 Long-EZ because when Terry Lamp built it everyone else was installing O-235s.  The baffling in that Long-EZ’s O-320 was per the O-235 IIL plans and caused some significant heat issues. I’m not calling Terry out nor being critical of him… that is an outstanding bird, and the poor guy had only the guidance for the O-235 to follow at the time!

With the above foundational info in hand, I then got to work on what Steve Beert calls the “Starship Enterprise” baffles.  First, here’s a shot of the separate baffle segments micro’d together to make one baffle piece per side.

I then marked the bottom edge of the top inter-cylinder baffles for trimming…

And then trimmed them up.

After another round of confirming the shape and configuration of these baffles, I then trimmed them up even more to their final shape on the lower side.  Here’s Side A:

And here’s side B.  I also final trimmed the top sides as well including the curly Q’s.

I had thought about and even mentioned spray painting the micro black with hi-temp spray paint, but then just decided to use the Toyota glue to add just a hair more depth, fill some gaps around the edges and of course cover up the white micro.  In addition, this allowed me to use the Toyota glue (RTV? Whatever it is!) and get a feel for how it could be applied and manipulated.  It’s not the sexiest looking stuff here, but it’s done, and remember: these are on an engine!

With my mastery of the Toyota glue complete (haha!) I decided to knock out some low hanging fruit: attaching the bottom outboard inter-cylinder baffles.  I figured these are pretty low-vis baffles and if I really got messy with the glue while slapping these things into place then they wouldn’t be very noticeable, eh?

I started on the left side and applied the Toyota glue in 2 strips across each face of the somewhat Λ shaped baffle and then taped it in place.  I will note that when I cut the baffle on the imprinted edge that the form created, it came out about 0.030″ narrow on each side.  Each edge is still on the respective outside fin, just not fully all the way around… it’s just a tiny hair off kilter so each side was a task of getting the best coverage possible with a slightly askew and every-so slightly narrow baffle.

On the right side the tape wasn’t holding at all… and it was quite the melee getting it on and set in place.  As you can see I used wood and cardboard to wedge it into place.  Here’s a shot from the inboard looking out…

And a shot from outboard looking in.  I can definitely say I’m glad that this small but crazy baffle is in place!

In other news: I forgot about these 3D printed standoff supports which I actually printed out yesterday and just got around to taping them in place on the aft side of cylinder #2.

I then test fit the cylinder #2 aft baffle in place.  Both standoff supports need some very minor tweaking, with the inboard standoff (shown) needing a bit more added to the depth while the outboard standoff needs just the opposite.

And with that I double checked the bottom outboard inter-cylinder baffles and called it a night.

I started out today by focusing on trimming up the remaining engine inner baffles that I had not gotten to yet, which were primarily the top outboard inter-cylinder baffles.  Knowing that Steve Beert is The Godfather of CF inner baffles I sent him a quick message asking him a few questions specifically regarding these inter-cylinder baffles… in fact, I sent him this pic below to clarify exactly which ones we were discussing.  We had quite an exchange over text on installing the baffles.

Then a bit later Steve called me with yet even more information, tips and builder tricks on these inner baffles.  We spoke for a good 45 minutes, where he also went over some of the background of the design (Terry Crouch having done the airflow math and primary design with a lot of input by Gary Hertzler) of this style of inner cylinder CF baffles.  I sent this pic below as well of the bottom-side outboard inter-cylinder baffle with a question to clarify some info Steve have presented to me.

After talking to Steve, with now a bunch of informational arrows in my quiver, it was time to get to work.  I finished trimming and cleaning up the top outboard inter-cylinder baffles, or the baffles that Steve nicknamed: “The Starship Enterprise” and set them into place between the cylinders each side.  Note the taped popsicle sticks on each end to keep the separate baffle segments both in the proper left-right position on their respective cylinders, and also pressed firmly against each cylinder… the intent here is not to create a gap between the baffle segments, but to account for these two previous mentioned factors.

I then followed Steve’s construction sequence by whipping up some micro with the high temp HTR-212 epoxy.   This was a bit tricky both in access to the gap (on a step ladder leaning over the top of the engine) but since I didn’t want to make a mess on the lower internal fins of each cylinder (or the floor, etc.), I had to ensure that the micro wasn’t too runny… thus the medium thickness micro —with emphasis on the thicker— was a bit trickier to stuff down in that narrow gap without it wanting to come back out with whatever implement was being used to get it in there (a variety of thicknesses of stir sticks).  Patience won over though and I finally got a good bead of micro in on each side.

I’ll note that Steve used West’s black dye in his micro in this application, but since I didn’t have any on hand I will simply paint the white micro with hi-temp black spray paint.

Although the weather isn’t as freezing cold this evening as it has been off and on lately, I set up a heat lamp under each side of the engine pointing upwards and covered the cylinder areas with some aluminum foil covered insulation pieces to keep the curing micro from getting too cool overnight.  And with that I called it a night and left these micro’d inter-cylinder baffles to cure overnight.

To start off with, I’ll note that I don’t like bashing smaller companies who are putting out products for the experimental aircraft world… it’s great to have choices.  But enough is enough.  GRT really gets a bad grade this round (D-) with my order on their compression style EGT probes.

As par usual, there were zero issues with the mechanical process of ordering these EGT probes.  Call them up to ensure they have in stock, order two of them, card info, confirm address… 5 minutes and done.  On my porch a few days later.  EZ-PZ.

GRT’s Achilles heel, and biggest negative, is their product information and documentation.  I had a conversation with Nick Ugolini on this a while back, and he told me as an engineering tech writer he offered to write their manuals for them… for free!  They refused.  I asked another buddy of mine who uses GRT if he would go that route again with any future aircraft… he said no.  Why?  Not because of the quality or the functionality of their products —which is excellent— but again, with no robust documentation you spend way too much time on the phone with them and/or hunting for information that should be right at your fingertips.

Case in point.  I called GRT to get info on their compression style EGT probes because, once again, there is literally ZERO information on these on their website.  I asked about any recommended processes I should know for mounting these into the exhaust pipes? How does the configuration work exactly?  Do they sell the threaded mounting bungs? (no);  Any preferred vendors or sources of supply for the threaded mounting bungs? (no); Now, admittedly this last one I’m fuzzy on, but I swore I confirmed that the required mounting bung threads were 1/8-NPT.  Apparently not.  Neither was that information provided (via product info sheet) nor offered when I was clearly asking every question I could think of regarding the install of these compression style EGT probes.

Well, when my 1/8-NPT threaded stainless steel mounting bungs arrived today from McMaster-Carr, I quickly noted that they were not the correct size.  But what was the correct size?  After 15 minutes of no joy in trying to figure out this odd thread size, I punted and called GRT, leaving my message to have them call me back later as the standard process goes.  And a half hour later got my answer: M8 with 1.0 pitch.  Yes, being in the good ‘ol US of A we tend to use ASI vs metric, but I do use metric hardware enough to know that the standard pitch for an M8 thread is 1.25, not 1.0.  Hmmm?

After a good 30 minutes of searching in vane on the Internet for a vendor that sells a stainless steel M8-1.0 threaded mounting bung, I gave up and finally went to the only source of supply I could think of that would have such an item: Ebay… well, China to be even more exact.  Yep, there they were!  Less than 20 bucks for 3 of them shipped from Shanghai and only a month to get here.  Thanks again GRT!

In other news . . .

Today I finally finished the trimming and shaping of the majority of inner CF baffles. Over the past few days I’ve done a few redo layups since using tape on the forms there were few quality issues I had with some of the baffles. Thus the redoes.

With the glossy surface the lights blanket out some of the CF print, so I grabbed these lower angle shots to show different perspectives on the CF.

And as a reminder, the aft inner baffles are the same print as prop spinner and flow guide.

Overall I’m very happy with how the CF inner baffles turned out, and plan to start mounting them to the engine… after I get the aluminum fin standoffs made up and mounted to the cylinders first.

I started off today by calling GRT to order 2 of their compression fitting style EGT probes.  Knowing what I know now and the much improved clearance that these will provide I figured the time is right to get them installed.  Plus I confirmed with James that he would be able to weld on the required 1/8-NPT threaded bungs onto the exhaust pipes.  I’ll simply hold the other ones as backups for my other 2 hose-clamp mounted probes.

Out in the shop I started off by pulling all the tape and plastic off the cylinder #2 aft baffle with the fin standoff support bump now integrated into it (pic 1).  I then trimmed the CF around the edges a bit, removed the protective tape off the cylinder, and set the aft baffle back in place for a test fit (pic 2).

Here we have a shot from the side to show the cylinder #2 aft baffle with the fin standoff support bump integrated into the baffle (note: the baffle is about 1/8″ low so it’s not fitted to the cylinder in this pic).

I’ll remind everyone that this fin standoff support bump in the baffle is to allow for these standoff supports as Dave Adams did on his #2 cylinder as well.

I took a couple hours to cut some more CF and lay up a few spares of the inner baffle segments in case I ever run into trouble or just need them in general… before I send the inner baffle molds back.

I’ll also note that the Toyota RTV —that is apparently the cat’s meow for mounting these CF inner baffles— was delivered today.  Now I have no excuse not to get these baffles trimmed up and installed on the engine!

Which I plan on doing over the next few days.

I started off this morning by pulling the now cured #2 cylinder baffle —with the fin/baffle standoff support curve integrated into it— off of the aft side of cylinder #2.  I had put a heat lamp on it since the weather (and shop) was much cooler overnight.  I assessed the baffle a bit —all looked pretty good— and then set it aside to remove the bottom cowling to allow removal of the left outboard/cylinder #3 exhaust pipe.

I commenced to remove the tape securing the halves of the exhaust pipe together at the near-center cut and then cleaned all the tape gunk off with Acetone.

While I was doing all these shop tasks, I had already pre-heated my kitchen oven to 400° F and was baking my previously “super-soldered” brass oil sump standpipe fitting.  My goal was to separate the fitting from the standpipe tube to allow James to braze it with some 1/16″ Silicone Bronze welding rods I picked up to allow TIG welding brass. Well, an interesting thing happened, or didn’t happen… whereas at 400° F previously I was able to remove the soldered pipe from the fitting, now it wasn’t budging. Hmmm?

I threw the standpipe assembly in the truck as well and headed out to James to weld the exhaust pipe, and also have a discussion on the standpipe.  My thoughts, in composite parlance, is that I had essentially post-cured this sucker and that it was now battle-tested to withstand 400° F without any issue… very interesting.

Again, it’s a good hour over to James’ shop and since Jess had a light work day I brought her along.  Unbeknownst to me, Jess’s mom is from the same area (“out in the sticks”) where James’ shop is… so after James had welded up the pipe an elderly friend stopped by and a whole conversation of who-knows-who ensued.   Combine that with a late lunch/early supper in Jacksonville and we didn’t get back to my house until very late afternoon.

And here we have the final piece of the puzzle (better be!) with the left outboard/ cylinder #3 exhaust pipe welded back together.  Now I can start on the final configuration of the tips in earnest.

BTW, James confirmed my theory on the soldered brass standpipe.  He also quipped that if I’m seeing over 300° in my oil sump that I’ve got lots worse issues than the standpipe… good point James, good point! <ha>

Back in the shop I got to work on the cylinder #2 aft baffle with it’s new integrated standoff bump.  I cut a ply of CF to fill just where the standoff support form was located and another full ply of CF to hold it all together on the interior of the baffle.  I then mixed up some HTR-212 epoxy and laid in the small filler ply of CF (pic 1) before laying up the interior ply of CF (pic 2).

I then of course peel plied the layup.

I let the baffle cure for nearly 2 hours to tack up before then setting it back onto the aft side of cylinder #2 (which I taped up completely to protect from any errant epoxy).  I taped the baffle securely in place to the cylinder since this will be the final cure and set a heat lamp on it while it cured overnight (much colder tonight than last night).  I’ll also note that the cylinder #2 fin/baffle standoff support mold was still in place on the cylinder to ensure the final shape is as optimized as possible.

And with that, I called it a night!

I actually started off today out in the shop to do some more inner baffle layups (see below), but apparently in my haste to get stuff done didn’t grab any pics of the initial layups.

After I got the layups situated (thankfully the weather went into mild mode over the last couple of days) I modified my cylinder #2 fin/baffle standoff support template to a simple rectangular shape based off my test fit yesterday.  As a reminder, here’s what that looked like:

After I got the major dimensions dialed in on my CAD model, I then created a vertical arch that is 1/4″ high in the center for my fin/baffle standoff support mold.  I kicked off the 3D print of the mold and then went out to the shop to prep the cylinder for the mold.

Here’s the cylinder #2 fin/baffle standoff support mold taped to the front of the cylinder.  After I got the mold placed, I then spent a good half hour trimming and sanding the top and bottom baffle segments to get their mating edges even and just kissing the top and bottom edge of the mold.

I then taped up the mold, which then allowed me to secure the cylinder #2 top aft baffle segment in place (pic 1).  I mixed up some HTR-212 epoxy to apply peel ply to the mold only, and then wetted out the surface of the top aft baffle segment (pic 2).

I did some dry runs on the the bottom aft baffle segment before adding tape to the inside of it.  I then laid up the single ply of CF (note: same print as spinner!) onto the free and unattached bottom aft baffle segment before securing it into position with its inside taped surface… I pretty much had to work it this way since the oil return line is in the way and I didn’t want to have to try to layup the CF around and under that oil line.

After I got the ply of CF laid up and trimmed I then laid a piece of plastic over it to provide that glossy, non-bumpy surface like all the other inner baffles have.  I then left it to cure overnight.

After getting the aft baffle on cylinder #2 squared away, I then pulled the peel ply and did some trimming on the narrow top outboard inter-cylinder baffle segments.

Here’s the non-cylinder mating side of those baffle segments… and I’ll remind everyone that these will get merged (separately, one per each side of the engine) with the larger end baffle segments to create the top outboard inter-cylinder baffle segments…

And to be clear, here are a couple shots from a couple different birds on how the top outboard inter-cylinder baffle looks when completed:

I’ll note that tomorrow I’ll be heading out to James’ shop to get the last exhaust pipe welded up, so it will be a slightly lighter build day.

I had some decent build plans for today but it turned out to virtually be a non-build day in most regards.  Last night I got an email saying that our monthly EAA meeting was this morning at a local restaurant.  I texted the new Canardian in the area, Guy Williams, about the meeting since I wasn’t sure if he was on the email.

I also received a text from my friend asking if I could watch her daughter, aka “my little buddy,” while my friend went to a doctor’s appointment.  No problem there either.

After the EAA meeting, Guy and I went to the airport to check out his Long-EZ.  It’s a beautiful classic built in 1982.  He and his dad, who owned it for many years before Guy took ownership, converted it from an O-235 to an O-320.  Guy moved out here this summer from Tehachapi, CA… home of Marc Zeitlin and Mike Melvill.  Thus Guy clearly had plenty of expert help on hand to assist with engine conversion, etc. on his Long-EZ.  And of course it’s great to have another Canardian at the airport, especially one of the Long-EZ persuasion!

Now, in my mind I figured a doctor’s appointment would take an hour or two at most, and although I only know that it was NOT anything serious, this appointment ended up being over 4 hours… that had me on kid-watching and entertaining duties.  By the time I got home it was well past 4 pm and I was due to have a dinner/evening out with Jess… so my already shortened work day was severely truncated by events that plopped onto my schedule just the night prior.

Out in the shop I pulled all the laid up baffle segments off their respective molds and pulled all but one piece of peel ply (only because it has such clear baffle edge trim markings on it).  I can tell you the added 6-8 hours of cure time with these baffles on the molds was felt significantly as they were MUCH harder to get off each mold!

Here’s the tally, starting CW from the lower left corner:
– “Old” top outboard wide inter-cylinder baffle (to be joined with narrow baffle segment)
– Opposite side of above, just laid up… now just need to layup narrow parts for these
– “Old spinner print CF” end baffle now relegated to duty on front of cylinder #4
– 2 pcs for cylinder #2 aft end narrow baffle that will get middle fin extension area added
– New “spinner print” aft end baffle with much better looking CF for cylinder #1
– New narrow end baffle for front side of cylinder #3

Also, before I headed out to the shop I quickly drew up in CAD and then 3D printed an initial template for the cylinder #2 fin extensions and associated baffle curve over these extensions.  Here’s the result that I temporarily taped up in place.

And an idea of how the top and bottom baffle segments will get melded with the upcoming semi-circular cylinder fin standoffs.

With that, it was time to get inside, clean up and head out for a Saturday evening with Jess.  Tomorrow I definitely intend to get at least the 2 partial narrow baffle segments glassed up for the other half of the top outboard inter-cylinder baffle assemblies that need to be floxed together back-to-back to make up those baffle segments.  I would also like to get some machining done, with the baffle extensions getting made to confirm the configuration for me to then “glass” (CF) up the gap on frontside cylinder #2 baffle.

Moving forward!

I started off this morning by pulling the two cylinder base inner baffles of their molds, as well as the new cylinder #1 aft end baffle off its mold.  The big reveal I mentioned yesterday is that they’re sporting the same CF print as the spinner and flow guide!  The cool thing is that these will all be fairly visible on the aft side of the engine when you look into the aft cowl opening.

Unfortunately, this CF is a bit thicker weave and I think I was a hair thin on epoxy in a few spots so the spots look just a tad dry in the light (just cylinder #1 baffle).  I have no doubt that it will still work and that it’s mainly cosmetic, but I’ll be relegating this new cylinder #1 aft end baffle to the frontside of cylinder #4, where it’s not as visible.

Along with the cylinder baffles, I laid up the second set of “accessory” pieces that are shown along the bottom of the pic (from L to R): the top inboard inter-cylinder baffle plate, the bottom outboard inter-cylinder baffle, and the angle bracket that screws into place between the cylinders at the top to secure the top inboard inter-cylinder baffle plate.  All told, this completes the cylinder base baffles and the “accessory” baffle parts.

For the larger cylinder end baffles that still left a redo on the cylinder #1 aft end baffle to get better epoxy coverage, and another partial end baffle for the other side top outboard inter-cylinder baffle.  Again, these partial end baffles will be merged (separately) with a pair of also partial narrow end baffles (below) that at full length are for the front side of cylinder #3 and the aft side of cylinder #2.

Speaking of which, I prepped the narrow end baffles by taping them up first with blue tape (pic 1) and then using the Tyvek tape on top of that as a mold release (pic 2).

I’ll note that on the cylinder #2 baffle I added a lip [a curl would be much harder to fit into place with oil line present] and a curl on the cylinder #3 baffle [also an oil line present, but at the forward side of the cylinder the bottom length of the baffle will be shortened with the curl positioned much higher up/closer to cylinder].

I then did the inner baffles Round 3 layups, which from left to right is as follows:
another partial end baffle for the other side top outboard inter-cylinder baffle;
the redo on the cylinder #1 aft end baffle;
top & bottom sections of aft cylinder #2 baffle (middle to be laid-up over fin extensions);
narrow front side end baffle for cylinder #3;
extra top inboard inter-cylinder plate (if/when fuel spider goes underside…bottom of pic)

My last point of note for the day on the build is that I spoke with my welder, James, who has been quite busy as of late, to set up an appointment on Monday to get the last exhaust pipe (cylinder #3) welded up.  From there I can do my end trimmings and final tweaks to get this exhaust pipe saga closed out.

Tomorrow I plan on doing another round (hopefully final) for the engine inner baffle layups.  This should get me close to having the full set I need to start trimming these inner baffles up and installing them all.

I started off today with a couple hours of research.  Although the weather was forecasted to be significantly warmer than yesterday, I figured I would wait until the afternoon to start work in the shop to let it naturally warm up a bit.

My research focus was on something that Andreas Christou discusses in his article, Design for optimal cooling efficiency, where he points out that the design of Lycoming type cylinders leaves the front of cylinder #3 and the aft side of cylinder #2 with virtually zero depth on the cooling fins (in a small area it’s literally just flat).  His suggestion as depicted in this diagram from his article (and yes, it’s upside down for us Canardians) is to create a standoff on the cylinder to extend —or literally create— the fins to support the baffle along that segment of the cylinder.

I had a discussion on this with Mike Beasley over lunch when he and Marco came down to visit me and Jess.  He mentioned that Dave Anderson had done a “washer trick” or something to create a gap on the #2 cylinder to account for this issue, and that Dave had purportedly resolved his hotter #2 cylinder cooling.  I’ll further note that from my gathered info, from accounts of other pusher drivers, and specifically from Mike and Marco at lunch: cylinder #3’s CHT on our birds doesn’t seem to suffer from a lack of a standoff.  We concurred that it was most likely since it was just aft enough and in direct line of the incoming cooling airflow, both on NACA and armpit scoop cooled EZ’s, that it seemed to cool as well as the other “tamer” cylinders.

A couple days ago I hit up Dave Anderson on FaceBook to ask him “How he done it?!” He said he was heading out to the airport in a day or two and would grab me some pics of what he had done to resolve this issue.

Here are the pics that Dave grabbed for me showing his cylinder #2 aft baffle configuration.  Note that the outboard baffle is simply off/away from the cylinder fins by about 3/16″.

And here’s a closer shot of that standoff.  I asked Dave the difference it made and he said it was considerable, about 100° F cooler for that cylinder.  Pretty impressive in my book!

Then, as I was perusing through the earlier issues of the COBA Canard Aviation Magazine this morning, mainly looking for Steve Beert’s excellent write-up on the engine inner baffles, I ran across an article by Dave Adams from April 2021, Issue 142, that showed what he did to resolve/mitigate this cylinder #2 standoff issue.  Funny thing is when I first started looking at the article I just quickly noticed the name and thought, “Dave wrote an article on this, why didn’t he just tell me to read it??”  After another look I realized it was Dave Adams.  Oops! (So many Dave’s in the canard world, eh?!)

Here’s a shot out of that article of some thin standoffs Dave added to the aft side of cylinder #2 to create the standoffs I’m talking about.

Moreover, Dave Adams solved another head-scratcher for me as well with the depression in the fins at the top of all the cylinders.  When the baffle covers this part of the cylinder fins, clearly it lets air escape out the sides.  Dave added mini walls at the outboard fin on each side to keep the cooling air channeled in the middle.  Quite smart and I intend to follow suite… because as we all know, any extra bit of cooling we can get on these birds —without adding drag!— is golden.

At this point in the day the weather had warmed up a good amount, so I headed to the shop to do Round 2 of the 2-ply CF layups on the inner baffle forms.

Starting in the top left corner in the pic below are the final 2 base cylinder (inboard) baffles [I have a surprise reveal on these and the other cylinder #1 aft baffle <far right in pic> tomorrow!].

The baffle form in the center of the pic with about half of it covered with the CF layup is the first of 4 of these separate cylinder “end” baffles that will get paired off and combined back-to-back to make the top outboard center baffles.

Finally, along the bottom row we have the second set of the bottom inter-cylinder baffle (V shape), the top inter-cylinder securing angle bracket (L shape), and the top inboard inter-cylinder baffle plate (cross shape).

After adding some peel ply I then left this round 2 set of inner baffle layups to cure overnight.

Today was a very cold day weather-wise so I didn’t do any layups in the shop since the preferred working temp for the HTR-212 hi-temp epoxy is a minimum of 80° F.  And I just didn’t want to have to jump through all the hoops of using heat lamps and heaters, etc. to keep the layup and curing areas warm.

I did mount the bottom cowling to check out my latest clearance protrusion.  Not something that I of course prefer to have present on the bottom cowling, but a must to provide necessary clearance with the #2 cylinder exhaust pipe.

Hindsight is always 20/20, so knowing and seeing now what I couldn’t really get when I started, I could have easily taken this cowling bump about 1/4″ inboard and about 0.150″ less in height at the vertical edge to make it a bit more diminutive in the airstream.  Hard to see all that when you’re visualizing and just going off the marked up Sharpie borders of the exhaust pipe.  Yes, I may have a bit more constant drag caused by this form, but I also alleviate any contact between exhaust pipe and lower cowling.

On the inside I checked not only the exhaust pipe clearance, but flipped the EGT probe securing hose clamp around 180° so that the screw portion of the clamp was facing forward.  I then checked the clearance under the hose clamp screw and it’s right about 0.47″… close enough to 0.5″ clearance so I’m calling it good.  That of course provides plenty of clearance for the exhaust pipe itself.

This hose clamp repositioning also gets that clamp screw out of the line of fire to allow freer access to the spark plug for install/removal, but then also adds to the bottom depth of the exhaust pipe as I showed in this pic a few posts back.

I then spent a bit of time pulling the now cured Round 1 inner baffle 2-ply CF layups off their respective forms.

Here’s a closer shot to show the weave of the CF.  Thankfully not only did the parts come off the forms easily enough, but they didn’t tear up the forms… easily allowing another round (#2) of layups to hopefully knock out all the parts required for these inner baffles.

With that being said however, tomorrow is forecasted to be even colder than today, so I will probably get some much needed personal stuff done and forego shop ops altogether, other than just trimming the excess CF off these parts.

Pressing forward… haltingly!