I started off by tweaking the right strake storage hatch initial bottom side lever assembly’s fit into the aft corner strake hole… and after a good half dozen iterations this one finally fit (pic 1).  Thus my CAD model now matches reality on the bottom strake hole.  The left side, not having as pronounced of a flat segment of the hole (to allow the wing bolt securing brackets to be installed) took less iterations to dial in (pic 2).

I then added the aft tab to both of my wing root aft heat shields and cut out new, complete cardboard templates.  I then test fit those and dialed them in on both the left and right side wing roots.

To scan the wing root heat shield templates above into CAD I had to cut them in 2 pieces to get the overall length of each scanned segment down to less than 11″, since my scanner only scans normal sized letter paper (8-1/2″ x 11″).  I then modeled up the templates and combined the 2 segments back together in Fusion 360 CAD.

At this point I needed to ensure my CAD models matched the original templates before plasma cutting the wing root aft heat shields.  This is where my 3D printed pen holder for the plasma cutting table comes into play, to essentially use the plasma cutting table as a big plotter (as Marco and I did on my instrument panel years ago).  I’ll again reiterate that this is good prep work in flushing out any tweaks that need to be made before tackling the much bigger firewall Titanium sheet-cutting job that is coming up soon.

The magnets on the original plasma cutting torch base aren’t strong enough to grip the new pen mount I created, so I needed to add some clamps for assistance.  I then printed out the left and right wing root aft heat shields with a Sharpie in the pen holder… I have to say that this setup worked quite the treat!

And then used scissors to cut out the CAD modeled/printed wing root aft heat shield templates from the card stock…

to then fit check them on the plane.  The left one (pic 1) fit fine but the right side was a hair proud along the top edge (pic 2).  After some assessment, I simply took 0.018″ off around the perimeter of the entire CAD model and called it good.  I’m sure I’ll need to do some judicious filing on the perimeter of these heat shields once they are initially installed anyway.

So after spending a good 45 minutes cleaning the squirrel poop and pink insulation out of my plasma cutting table water tray, and adding more water to it, I got on with the business of plasma cutting the wing root aft heat shields. I had to do 2 cuts on the left one to get it cut out completely, and about 6 —with cutting parameter tweaks— on the right heat shield to complete that plasma cutting job.

Here we have the left wing root aft heat shield on the top, which covers about the aft 2/3rds of the wing root.  While the right side, on the bottom, is a bit longer covering around 3/4 of the wing root.

I’m still undecided on whether or not I’m going to engine turn these heat shields, especially since they’re so thin at only 0.02″ thick.  I plan on doing some testing on some scrap pieces tomorrow and will decide then.  For now I’m calling it a night.

After some domestic duties and running around getting errands done, today was more of a planning, assessing and design work day than it was an actual knock-tasks-out day.  It was also a spend another 30 minutes looking in all the usual suspect places for my bag of wire terminals.  Frustrating, but I found ’em.

In the background I’ve also been working on both designing and identifying parts & materials that I’ll need for the latches on the strake storage hatches.  Yes, I decided to go a little fancy on those as well with a lightweight cable latch handle situated in the ~2″ hole on the outboard bottom end of the CS spar (AKA strake) that when pulled will release the spring hinged storage hatch door on the topside of strake… very close in operation to my top cowling oil dipstick door.  Moreover, I’ve been doing some initial modeling in CAD with dimensions I took off those bottom strake access holes.

Out in the shop I spent WAY too long (nearly 45 minutes) mounting an Adel clamp around the fuel hose where it exits the engine mount.  It was a bear to get that screw in there given the limited access to those clamps, but in the end I got it done.  I’ll note that I wanted this Adel clamp at this spot on the fuel hose for 2 serious reasons:
1.  The steel 90° hose end fitting is cantilevered straight out horizontally from the fuel pump fitting, so I wanted to ensure I support the hose and not have the fitting under stress and/or slowly lose its grip over time.
2.  The Cozy Girrrls, God bless ’em, welded a reinforcement plate in the corner of the engine mount they sold me.  Well, I had literally no other way to route my fuel hose off of the fuel pump other than right where it is.  This meant removing a chunk of that reinforcement plate.  Which further means there is essentially a dull knife blade mere fractions of an inch away from my main fuel feed out of the fuel pump to the fuel injection servo.  In case scenario #1 above were to ever happen, I didn’t want the vibrating engine mount gnawing a hole in the fuel line if it lowered in position over time.  The Adel clamp is positioned as a literal physical barrier between the fuel hose and this engine mount plate edge.

In short, this just-installed Adel clamp was both an essential and critical requirement for safe operations of this engine, IMO.

After playing “find me if you can” with my wire terminals, I then spent nearly 3 hours looking at the last 3 major cable/wire runs coming off/out the lower right firewall corner.  Again, this is the big yellow starter cable, the white 8-ga alternator B-lead, and the smaller white alternator field wire.  In addition, I verified and updated my wiring diagrams to include wire labels.

My initial plan was to run these cables just above the cold air intake tubes, and hanging off a couple of the oil sump perimeter bolts in Adel clamps, somewhat as I did with the EGT & CHT wires.  However, again that pesky fuel hose is right in the way of the big yellow starter cable.

I played around with different variants of my initial configuration for quite a bit before trying a completely different southerly route with the cables hanging off outboard side of the throttle cable lever bracket.  The one slight concern I have is the cable being in the general vicinity of the fuel injection throttle lever rotating back and forth.  The gap is more than sufficient for clearance, especially once the cables are secured, it’s just the pucker factor of anything getting close to that throttle lever.

To ensure the “southerly route” was viable, I mounted the lower cowling and spent a good 15 minutes trying to peak into any crack or crevice I could find to verify clearance between the cables in this configuration and the bottom cowling.  At every point I could see it all looked good and I’m counting this routing as a very acceptable option.

As I was walking back to the house, having closed up the shop, it hit me that maybe I could move the firewall exit point for the big yellow starter cable up an inch or two to provide more clearance between big yellow starter cable and the main fuel hose in going a more VFR direct routing betwixt firewall and starter lug, via Adels off the oil sump.  I’ll take a look at that tomorrow.

Regardless, enough banalities for the evening.  It’s getting way too late.

Pressing onward!

Before starting in hot n’ heavy on the EGT and CHT probe wiring connections I did a quick check of my newly created gust locks.  On the outboard end of the aileron the gust lock went almost up to the very front part of the gap, so not overly effective (pic 1). On the inboard aileron gap the gust lock went in about halfway (pic 2), so it looks like it will work fine there.  Since I’ll have a trailing edge fence very close to the outboard aileron edge I might not use a gust lock there anyway.

On to EGT and CHT wiring…

One the main tasks here is to join the EGT and CHT probe wires with the EGT and CHT wires coming from the P10 CPC connector, which itself traverses the firewall into the GIB headrest compartment where the GRT EIS-4000 Engine Management System unit is located.

Each of the 2 wires coming from each EGT and CHT probe is already terminated with a female Fast-On connector, whereas the pairs of EGT and CHT wires coming out of the EIS-4000 —via the P10 connector— are long and need to be trimmed to length before a male Fast-On connecter is crimped to the end of each wire, to then be joined to the associated probe wire.  The EGT probes have red and yellow wires, while the CHT probes have red and white wires, all respectively.

All this is what is going on here in pic below.  I’m about half-way through cutting the long EGT and CHT wire pairs to length to marry them up with the associated probe wires.  Clearly since these wire pairs, with rather bulky connectors once connected together (plus secured and protected with a heat shrink sleeve), need to coexist in the resulting wire bundle of EGT and CHT wires, I’m trying to space the connectors out along the length of the bundle so I don’t get a massive lump of them all together in one spot… the proverbial egg in the snake.

I got about 3 wires terminated together (which I didn’t learn the trick on squeezing the Fast-On connectors together until over 2/3rds of the way done!) with heat shrink before I realized my brain fart of not checking continuity between newly crimped male Fast-On connector and associated D-Sub pin in the P10 connector.  Ahh, complacency!

I of course know the 3 wires I connected and documented them, so if any shenanigans start up they’ll be first up on the culprit list (read: I didn’t crack open those connectors).  But from the 4th wire on I ensured I checked continuity, and all of them were good.

An entire work day and work session later, my EGT and CHT probe wire terminations, connections and wire management was finally complete.  Getting up into the bowels of the engine to clamp together pairs of Adel clamps while the wire bundle is contained is a feat unto itself, as those of you that have installed Adel clamps can surely attest to.

Case in point, on the cylinder #3 EGT probe cable I needed to secure the outboard portion of the wire to keep it from rubbing on either the cold air intake tube or the oil return line.  I tried a couple different things, one using a heat shrink wrapped zip tie, but I didn’t like the results.  I punted and installed another pair of Adel clamps outboard of the first set on the oil return line to secure this cable (visible just in front of the cold air intake tube).

If you play “Where’s Waldo” you can see all 4 left side EGT/CHT probes and their wire runs to the right side of the engine.

Here we have a shot looking down into the forward right side engine compartment. You can just see the P10 CPC connector in the top right corner (pic 1) and the gray-wrapped bundle of EGT/CHT wires secured to the right side motor mount with an Adel clamp towards the top and a heat shrink wrapped zip tie mid-picture (pic 2).

I left the bundled and secured EGT/CHT wires in their natural state (chaotic…ha!) in the area under the engine since it’s not readily visible from the top (yeah, screw performance, it’s all about looks!).

Here’s a couple of shots of the aft right corner of the engine looking up at the EGT and CHT wire runs all bundled and secured.  A good bit of the craziness is again due to my spacing out the Fast-On connection points in my attempt to not only space them out to reduce wire bundle diameter, but also to avoid having the junctions meet up where the Adel clamps are installed.  This involved a good number of loops and switchbacks to get the probe wires at the correct matchup lengths.

Yeah, who knew terminating, connecting and running EGT and CHT wires was a whole sub-project in its own right?! (Any Long-EZ builder, that’s who!)

After winning my hard fought battle with the EGT and CHT wire runs, I then took a good 45 minutes to assess the final alternator and starter cable runs.  I stress FINAL since original plans of how these components will get installed always tend to get blown out of the water after other things are stuffed into place.

Case in point is my 8-ga B-lead alternator wire.  When I first planned it’s physical course from alternator to firewall, there was not a rearward-facing fuel injection servo nor a 180° carbon fiber air induction tube blocking that route.  Now clearly there is… as we used to say in the Air Force, and as I taught Jess: Flexibility is the key to Airpower! (Hoo-ah!).

Or the ‘ol tried and true statement from my EOD days: Improvise, adapt, and overcome.

And with that, I developed my plan and my task list for connecting up the last 3 wires in the engine compartment: 1) Big yellow starter cable (won’t be finalized until after firewall covering in place); 2) Alternator 8-ga B-lead:  I’ll run, attach, and terminate soon, pre-firewall; 3) Alternator 20-ga field wire: this will run through the same firewall opening as the Big yellow starter cable, and since I need to extend this wire’s length anyway (splice in more wire) I may add a connector near the firewall… assessing.

And with that, I called it a night.

I started off today by pulling the peel ply, razor trimming the overhanging glass and hitting the edges with a sanding block on the aft wing root closeout that essentially seals up the wing root area as a fire block, on each side respectively of course.  Here we have the left side (pic 1) and the right side (pic 2).  Next up will be configuring and cutting out the aft wing root heat shields in prep for mounting.

I ran out for some errands and to grab lunch with Jess.  Shortly after I returned home mid-afternoon UPS delivered the 5/8″ tube bender I ordered off of Amazon.  Well, 15 minutes later I pressed it into service to shape the 5052 aluminum tube that I ordered from ACS.

I took my time to ensure I didn’t create too much of an angle on any one bend, but even with just the normal, slow, don’t-screw-this-up! workflow it took hours for me to get this one darn tube bent to flow with the exhaust pipes AND be angled up and outboard at a good angle on the front end to intersect the black crankcase vent hose.

After countless iterations of mounting the tube, removing it, bending an angle just a hair and then remounting it, I finally got to a point where I was ready to cut the black crankcase vent tube hose to allow me to join it to the aluminum vent tube.  However, when I tried to use the big wire cutters, that mo-jamma hose just laughed at those cutters.

I tried a couple of other cutting implements, but in the end my razor knife did the job… albeit not elegantly (But I didn’t stab anything in the engine compartment or ME!).

And here we are: the 5052 aluminum crankcase vent tube installed!

And here’s a shot of the ‘middle area” with the 2 forward hose clamps securing it to the exhaust pipes.  I’ll further note that I have a temporary hose clamp on the aluminum tube to black rubber hose connection until I do final install on the crankcase vent tube (after the exhaust pipes are officially installed… soon).  When I do the final black hose to aluminum tube connection I’ll secure it with wire using my Clamp-tite tool (much lighter!).

And here we have a shot of the very aft end of the crankcase vent tube (pic 1) and the forward end with black rubber hose going up to the crankcase vent exhaust port (pic 2).

I then turned off the lights in the last 2 shop bays and placed lights on the top right side of the engine to spot any offending gaps in the baffle sealing hi-temp RTV.  I worked the right side for nearly 45 minutes before heading over to Jess’s for a late dinner.  I still have a few more difficult-to-reach areas left to do, which I’ll hit in the next day or so.

I’ll also note that as I was doing research over the last week I found an article in the COBA magazine from Mike Beasley relaying a conversation he had with Terry Schubert on making control surface gust locks.  In the article Mike said he used 0.025″ thick 2024 and then painted them red (actually he told us to paint them red, he hadn’t done so as per pics shown… poor execution in my book! Hahaha!).

With the dimensions nicely shown in the article, I spent less than 10 minutes modeling it up in Fusion 360 CAD to then 3D print one out in red ABS.  I used a thickness of 0.032″ since this is plastic, but it still came out fine.  Probably a bit more flexible then the aluminum, but strong in sheer nonetheless.  Moreover, it took me about 2 minutes to kick off 3 prints total on these, which I did over the last couple of days.  Voila!

Tomorrow I plan on continuing my engine installation push!

I started off today by pulling my unconventional wire and string off the inboard wing CAMLOC flanges that secured the respective carbon fiber closeout tabs in place.  BTW, these CF tabs are 0.03″ thick and weigh about a gram apiece.

I then spent a good 1.5 hours cutting 2 plies of BID for the inside layup on each side, and a ply of BID for both aft outside corners as well.  Plus of course the associate peel ply for these layups.  I then prepregged the inside layup BID plies.

Sorry for the not great pic of the inside 2-ply BID layup on the left side, after I filleted the corners with micro (vs flox for weight) [pic 1].   And the 1-ply layup on the aft side after adding a fillet in the corner (pic 2).  I then peel plied the layups and left them to cure.

And repeated the process on the right side.  Inside layup (pic 1) and aft outside layup (pic 2).

I then pulled the peel ply off the firewall threaded ground stud insert and tested out how the ground bolt would thread in/stick out the firewall and how the ground strap flows around the main fuel feed line to the firewall ground stud.  I’m very pleased with this mod and think it will make any engine removal or ground strap work much easier.

And it was now time to tackle the EGT and CHT wires coming from the P10 firewall engine sensor data connector (pic 1).  I wrangled all the wire pairs and got them somewhat organized (pic 2).

I then routed the EGT/CHT wire pairs down the right inside of the engine mount and secured them in an Adel clamp.

Instead of routing both sides’ EGT and CHT wires around the front of the engine, I’m taking the left side wires straight across the lower aft of the engine to the right side, then running all the EGT and CHT wires out the front right of the engine to the P10 CPC plug. I’m doing this in part to keep the EGT and CHT wires away from the bottom unshielded P-Mag spark plug wires, thus anywhere they do come in the vicinity of spark wires they cross perpendicularly as close to 90° as possible… all to mitigate EMF noise.

It may be a bit difficult to see, but here is the left front EGT cable attached to the cylinder #3 oil return tube with Adel clamps.

Here we have all the left side EGT and CHT wires meeting at the aft left corner of the oil sump where they are secured by the corner sump bolt.  Since this is an AN4 bolt I had to drill out the Adel clamp mounting holes to 1/4″.  In addition, I chucked the old star washer and installed a fresh one and torqued the nut back to its original 96 in-lbs.

Again, if you look closely I did the same thing on the oil sump bolt just to the right of the crankcase centerline where I added an Adel clamp to secure the left side EGT and CHT wires.

It was getting fairly late so I called it a night.  Tomorrow I plan on wrangling the right side EGT and CHT wires AFTER I get the new crankcase vent tube bent and installed (the tube bender is supposed to be delivered tomorrow).  Of course there’s a myriad more tasks to do on this engine install, but I’m nugging my way through them!

Today was all about making an aluminum threaded grounding bolt insert for the firewall engine ground bolt.

Before I started that however, I pulled all the forms off the wing root heat shield mounting tabs.  I have some minor gaps on a few of them at the corner 90° bends, but besides that they came out really good.  My plan is to actually mount the #6 screw platenuts before I trim the mounting tabs, which I’ll do once I pull the engine off the bird (way easier then).  In addition, I’ll construct the forward heat shields and glass in those tabs once the engine is off as well. I’m just getting everything done as much as I can with the engine on, in my attempt to get the engine installed and engine compartment configured.

At some point in the recent past —I believe when I installed the throttle cable through the firewall— I realized that to remove the engine ground strap from the firewall in EZ fashion that I had the main ground bolt going the wrong way: inserted into the firewall towards the nose.  This meant every engine or ground strap removal required me getting a wrench up into the busy hell hole on one side while unthreading the ground bolt from the firewall side… too much hassle for my lazy self.

Now, at first I was scratching my head and just could not remember exactly why I didn’t just reverse the bolt (vs the big hole?) and add an extra nut to secure it to the firewall, then mount the grounding strap terminal with a final securing nut… then I finally remembered that for some reason in both the B&C instructions and Bob Nuckoll’s book “AeroElectric Connection” the grounding bolt went through a stack of washers, which were the thickness of the firewall, to secure the engine ground strap on the firewall side and the ‘forest of tabs’ on the hell hole side.

Thus, my plan is to replace that stack of washers by embedding a threaded port on the firewall to secure the 5/16-18 brass firewall ground bolt into, from hell hole side aft, without having to mess with any tools in hell hole once it is initially installed: meaning threading the bolt into the hell hole ground block (‘forest of tabs’) through the firewall threaded insert, once, and then be ready for the engine ground strap on the engine side [which can be taken on and off at will without needing hell hole access].

Yep, should all be EZ-PZ once complete.

The initial issue was the shoulder on the 5/16″ brass bolt that came with the forest of tabs, as with many bolts, would not allow me to thread the bolt into the firewall grounding point without a 1/2-inch or so sticking out.  I needed the threads to go up to the head of the bolt.  So I chucked up the bolt in my lathe (pic 1) and hit it with a 5/16-18 die to add some threads to that sucker (pic 2).

Ahhh, much better!  Now we have threads nearly all the way up to the head.

I then removed the bolt and chucked up a 9/16″ diameter 6061 rod into the lathe and hit it with a center drill to get a good starter hole for drilling.

I drilled into the end of the 6061 rod with a letter F (0.257″) drill bit ~1/2″ deep (pic 1) before tapping threads in the hole with a 5/16-18 tap (pic 2).

I then tested the newly formed threads with my brass grounding bolt.  Looking good so far!

It was now time to cut off the threaded nub at 0.38″, which is the approximate thickness of the firewall depth (it varied depending on what side of the hole I measured due to overlapping corner BID tapes).

Once the threaded firewall ground nub was removed, I roughed up the perimeter with the Dremel tool and tested the fit of my freshly cut threads… on both nub and bolt.

And test fit it into the firewall.  Again, so far so good!

I then prepregged 2 separate square plies of BID, wet those out and slathered up the firewall threaded grounding bung with flox (with Saran wrap in threads to protect it).

I then put the threaded grounding bung into the floxed firewall hole (pic 1) and laid up a ply of BID over top of it on the firewall side (pic 2).

I then laid up a ply of BID on the hell hole side over the firewall threaded grounding insert, and then peel plied it.

Finally, I then peel plied the firewall side layup as well.

Hopefully I’ve put the saga of the firewall grounding block AND the engine ground strap configuration to bed.

My last task of the evening was to add another fire block to the wing root at the aft end, where I scrounged around and found a thin scrap carbon fiber piece which I cut to make the small tabs (about an inch square) for the aft end of the wing root cowling flanges, for both sides. Yes, I realize that a lot of builders close these gaps up when glassing the wing root and/or when creating the cowling flanges… better late than never I guess!

Regardless of my lack of planning (wink) I used my leftover epoxy in the cup from my firewall grounding bolt threaded insert flox install/layups to whip up some flox and secure these minute tabs into place on the end of each set of wing root cowling mounting flanges, for both the left (pic 1) and right (pic 2) sides.

As par usual, I had planned on getting a lot more accomplished today… it’s amazing how much time these seemingly small tasks often take to complete.  Still, it’s done and I’ll continue to push forward.

Today was all about knocking out the wing roots’ heat shield mounting tabs for the aft heat shields, which cover a good 2/3rds of the entire wing root.

This specific style of wing root heat shield was designed by Steve Beert after he had a plans spec heat shield break and a part of it go out the back of the cowl through the prop.  Luckily there was no damage, but he changed up the mounting style of his heat shields.

I’m pretty much copying Steve’s design, with a slight modification: due to the oil cooler on the left/port side and the autopilot roll servo on the right/starboard side, the front 1/3 of the heat shield will be inset into the wing root about 1.5″, whereas the aft 2/3 segment will be pressed up against the wing’s cowling mounting flange inboard edge.  There will be an intersecting dogleg at the junction between the two segments.

Here is the left side, with temporary slats to support the vertical portion of each laid up mounting bracket, which is essentially an “L” bracket facing into the wing root.  I prepregged the 5-plies of BID for each 1″ wide x 2″ total length tab.  After laying up each sets of tabs I then peel plied the layups.  I’ll further note that I used the same high-temp resin (HTR-212) on these brackets that I did for the internal carbon fiber engine baffles.

I then did pretty much the exact same thing on the right side.

Now, these layups certainly aren’t crazy hard, but with all the plies of BID that needed cutting (all scraps BTW) and working close to blind laying up the BID on the backside of the slats, it took nearly 5 hours total to get these layups knocked out.

Tomorrow I’ll do some more work on these and also attempt to get the bottom cowl aft baffle seal rib layups started.

Ok, this post covers the last couple of days…

First off, I did a fair bit of assessing and poking around to figure out what to do on my crankcase vent tube issue.  I didn’t want to keep pouring time into the welding solution in case that doesn’t play out the way I would like.  I needed some backup and initially that was the 5/8″ stainless steel tubing that I have on hand, which I originally ordered (a way long time ago) after seeing that is what James Redmond used.  However, after figuring out we’re talking a near 6 oz weight increase, I decided to bite the bullet and order some more aluminum tubing stock, both 6061 and 5052.

After settling on Aircraft Spruce as the source of supply, and paying the small fortune for shipping, I spent another good hour scrubbing all my hardware requirements to add those to the order.  If I’m paying more in shipping than what the tubing costs, I want to maximize what I could add to the order for “free”.  I also spent a good hour looking around for a decent priced 5/8″ tube (not pipe! there’s a big difference) bending tool, which I final settled on one from Amazon… all this stuff arriving early next week.

Administrivia and requisitioning duties complete, I then turned back onto the build.

First up, I took the top cowling outside and sanded down the carbon fiber patch I had just laid up the day before.  There was still a bit of a concave dip on the right vertical aft wall, so I laid up one more carbon fiber strip, about 1/2″ high by 5″ wide.  I then peel plied it.

After some more assessing and figuring out exactly how my wing root heat shields will be configured, I decided that the last little open gap at the trailing edge wing root needed to be filled in to keep any air (or fire in this case) blocked out… since I wasn’t going to cover that with the heat shield.

Thus, as a prerequisite tasks to installing the wing root heat shields, I made up some cardboard dams for pour foam, taped them up and secured them in place on each side.

I then whipped up a small batch of pour foam and applied some to each aft corner wing root.

About 20 minutes later, I pulled the taped cardboard dams off the pour foam, cleaned it all up and shaped the pour foam.

I finalized the prep of the pour foam, made little “flox” corners (micro used here) and cut out a ply of BID for each side.  I then whipped up some epoxy and micro’d up the pour foam.

I then laid up a ply of BID on each side… which is hard to see because the small bit of BID on the edge kept wanting to lift off at the top corner (each side) so after adding peel ply, I taped the layup down at the corner.

While my aft wing root layups cured, I then spent nearly 2 hours with half the shop lights off, with work lights on the top of the engine to find any small gaps in the baffle seals… which I then gooped up and filled with hi-temp RTV.  I finished the left side of the engine, as well as around the alternator and starter on the aft side.  I still have the right side to complete, as well as a big 1 sq. in. hole on the forward inboard left side (I’ll either have to rivet in some aluminum or make an RTV-BID patch for that).

Continuing on with my completely un-sexy, but required, tasks, I then assessed the engine ground strap run from the front right corner of the engine to the firewall.  When I started this final assessment, I thought I was going to have to move the firewall ground block since the routing of the ground strap was virtually right through (or rubbing against) the main fuel feed line from engine fuel pump to fuel injection servo.

However, after simply pivoting the ground strap terminal on the engine inboard about 0.3″, it provided me the clearance and slack I needed to route the engine ground strap around the fuel line to the original ground block position.  And no, I didn’t discover this right off the bat, but rather after about 45 minutes of playing Firewall Tetris with the engine ground and power cables.  Anyhoo….

Tomorrow I’ll be working more engine stuff in attempt to wrap up all the remaining engine install tasks to then allow me to pull the engine and work on the firewall install and also micro finish the top side of the bird in prep for painting.

My goal today was to get the crankcase vent tube forward angled segment —which cracked off while I was bending it— welded to the remainder of the tube, and then hopefully move on to getting the dipstick rod joined to the dipstick cap.

But first, I kicked off the morning with some cowling repair by adding some carbon fiber plies to some low/concave spots and divots.  In these small areas I would rather add smaller patches of carbon fiber and sand it down even, then to have thicker applications of micro which tends to crack over time on the ever-vibrating thin-walled cowlings.  So using a small amount of mixed up epoxy and a few selectively cut carbon fiber scraps, I made my repairs (I’ll note that I used the ProSet epoxy which I recently heated up to bring back to liquid vs big glob form).

I then left my cowling repair layups to cure as I did a bit of research on welding 6061 aluminum.

Once back out in the shop, I trimmed down the cracked edges at the break in the crankcase vent tube and got to work on welding that back together.  I first did a good amount of TIG runs on some scrap 6061 and felt I had decently warmed up for this welding session.  However, I have to say that I’m bit flummoxed with the sheer ugliness that ensued.  I’m not a great welder, but I’ve held my own in a number of welding projects in the past: stick, MIG and TIG, so I’m not trying to blame my equipment… it could certainly be me.  But I just don’t seem to be striking good arcs, getting good puddle action or decent melting in of my welding rod.  I’m guessing I may need to do a total swap-out and deep cleaning of my electrodes, consumables, etc. because strange things are afoot at the Circle K.

I really didn’t want to keep attempting a bad position, so I stepped away from welding for a bit and concentrated on another required engine task: the dipstick.

Here we have the older, shorter stock Lycoming oil level tube and dipstick, as well as a 3/16″ diameter 6061 rod and an eBay special properly-threaded and o-ringed cap for the taller gold-anodized Superior oil level tube.  BTW, I found out about this aluminum cap from an RV bubba on the VAF forum.

It was time to join rod and cap to create a proper dipstick.

I started by taping up the knurled edge of the oil dipstick cap and mounting it into my lathe’s chuck.  I then set up a center drill (pic 1) and fired up the late to get me a nice center drill starter hole for my drill bit (pic 2).

I then drilled a 0.75″ deep hole into the underside of the oil dipstick cap…

which allowed me tap 10-32 threads into the hole (pic 1).  I then tested out my tapped hole with an AC grade bolt (pic 2).  All looking good this far.

I removed the oil dipstick cap from the lathe chuck and replaced it with the now cut-to-length 3/16″ oil dipstick rod, and then proceeded to create 10-32 threads on the top end of the rod with a manual die.

Here we have the cut-to-length 3/16″ diameter oil dipstick rod with 10-32 threads at the top end.

I left the dipstick rod chucked up in the lathe as I then secured the oil dipstick cap in the milling machine’s vise, with protective tape on each side as to not scratch the finish!

I then drilled a hole into the side of the cap down into the center of the cap to allow me to tap 8-32 threads into the hole….

which I did next.  This threaded hole will secure an 8-32 setscrew, which in turn will secure the 10-32 dipstick rod threaded into the dipstick cap.

With all my holes and rods threaded, I then gooped up the dipstick rod’s threads with Steve Beert’s magic Toyota hi-temp RTV before threading the dipstick cap onto it.

Last year I had to buy some 8-32 thread-locking cup-point setscrews for my AeroLED Nav/Strobe light assemblies (one would have thought they would be included in the light kit, but I digress…) and have quite a few left over, so I grabbed one to use here (pic 1) and started threading ‘er in (pic 2).

And Voila!  Here we have a new, functional dipstick rod and cap unit.  I put it next to the old one for contrast.

I then installed it into the Superior oil level tube (pic 1) and tightened ‘er up (pic 2).  Appears to work a treat.

Now, I clearly still need to create the oil level marks on the dipstick for it be of any real use, but I’ll do that when the plane is in more of a half grazing position as the bird would be during preflight.

I’ll do some more pondering on my crankcase vent tube issue, but it’s very late and I’m packing it in for the night.  Pressing forward!

My goal today was to get the crankcase vent tube installed to allow me to press forward with other engine installation tasks.  And I almost made it, except on the last bend of the crankcase vent tube it cracked… with enough force that when it let go it popped me on the forehead, leaving a nice little knot.

But that was later in the evening, and I’ll get to that in a bit.  Let’s start at the beginning with making the crankcase vent tube cradles and saddle (AKA “Batman Parts”) to allow securing the aluminum vent tube to the exhaust pipes with hose clamps without crushing the tube.

First, I spent a good little bit doing some research since I’ve never milled multiple parts before.  It’s not overly difficult, but there is a bit to learn in how to set the files up in Fusion 360 to be able to combine all the respective parts and set them up to post process them in CAM.

Moreover, these parts are only 0.58″ wide, where the only stock I had on hand was 0.75″ thick.  I grabbed the best piece for the job and clamped it up in the milling machine vise.  I then probed the stock to zero out the coordinates.

And then did about 5 passes with my Superfly facing tool to bring down the thickness of the stock to just a few thou off: 0.576″ thick.

Since I’m cutting the parts out of the entire thickness of the 6061 stock, I used my tried and true blue painters tape and super glue method to secure it onto a sacrificial wood plywood base.  Moreover, once I drilled the holes in each part (pic 1), I then drove a pair of wood screws into each hole to help secure these smaller parts in place (pic 2… I honestly don’t think they needed it, just insurance).

I can’t take really big cuts on material on my mill due to the TTS quick swap tooling system.  The downside to this system is that without enough clamping force, too big of cuts at the 3000 rpm I have available will pull the tool out of the spindle.  So what I’m saying is that it took a good little bit of time to mill these parts.  Here they are fresh off the mill (pic 1), and cleaned up a bit with their 3D-printed ABS prototypes (pic 2).

After deburring the holes and hitting the corner edges with a file, I test fitted all the crankcase vent tube inserts.  Here is the aft one in place… looking pretty good!

And the middle and forward inserts as well.  Again, they fit really well.

I hadn’t yet bent the 6061 tubing, so I tried out test-fitting the aft 2 inserts with the straight tube.  Still looking good.

I’ll note that I spent a good while working the position of the forward black rubber crankcase vent hose since it was a little close to the “shark fin” rudder cable bracket. In fact, I installed the right rudder cable going up to the nose to get a clearer idea of exactly how much space I had to cram all this stuff into the engine compartment.  As par usual, it’s all very tight in there.

I then used a scrap piece of softer 1/2″ diameter aluminum to get the angles dialed in to allow the aluminum crankcase vent tube to flow with the exhaust pipes.

Again, I did a good bit of research earlier in the day, to include bending 6061 tubing.  What I learned is that bending 6061 can be tricky, but this tubing here is fairly thin-walled at 0.035″ thick, and with the tube filled with sand I thought I’d be good. Especially since the first bend went just fine.  So after playing the 30 minute game of “find me if you can” I located my 5/8″ spring specifically for bending metal tubing… since my tubing bender tool only goes up to 1/2″.  I then got to work.

However, as I regaled you at the start of this blog post the forward bend, which would allow attaching the black rubber hose to the vent tube, let go and snapped as I was applying a good deal of pressure on it to bend.  I had a very thick-walled piece of PVC pipe clamped in my bench vise vertically, and had slid this aluminum tube down into the PVC pipe.  I had the bend at the opening of the PVC pipe, which was about eye level with me.  When it snapped it popped me right on the forehead… so, the ‘ol blood, sweat and tears is real on this build! (actually there was no blood… this time!).

Note the cracked tube in the upper right corner.

The good news as you can see in the pics above and below is that these milled cradles and saddle are functioning exactly as I designed, and fill around the tubing under the hose clamps very well.  Ironically, I may just end up switching to stainless steel since I have that original crankcase vent tubing stock on hand as well.

Tomorrow I’ll try cutting, welding and reinforcing the failed tube to see if I can salvage it. If not, I’ll probably have to order a no-kidding tube bender and either another aluminum tube, or press forward with the stainless steel vent tube.