I then moved on to mounting the ECM. Mounting options are limited based on the harness length so I opted to go a similar route to @rdb138 and mount it at an angle. I started by putting the ECM into the ECM holder (which is discontinued, thanks Chevy) and placing the ECM where I wanted it. I then bent some coat hanger into the rough shape of the bracket that would hold the ECM in that position.



From there I trimmed it until the leg lengths were about right. I decided to use 3/4" x 1/8" AL bar stock for the mount because Lowe's had it and I wanted more practice welding aluminum. After cutting the stock to length I bent it using some 1" round stock and a vice, using the coat hanger as a template. I also cut and bent some reinforcements to avoid the ECM vibrating and cracking the bracket.



I didn't want to rely on just the right angle pieces to keep the ECM from moving forward under braking so I added a horizontal member. It extends far enough aft to pick up a stud on the shock tower.



From there the ECM holder was riveted to the brackets and the brackets were mounted to the chassis with some M6 bolts.



There are a few more things I need to mount before the engine can go back in, but that list is getting pretty short.

 

Nice updates! I'm jealous of your aluminum welding, what welder do you use for that?

 

Thanks! I'm definitely not a good welder but I think the joints are structurally sound. I got an Everlast 200DV back when they were having a Christmas sale. Runs on 110 or 220V which is nice. The torch cooler is 110 only unfortunately, if I had to do it again I'd just buy a cheap one on ebay - the one Everlast sold me is identical to those anyways

 

I've been putting off painting the engine bay because I don't really like painting. The actual act of painting is pretty relaxing, but it just takes so much time to prep, mask, and clean everything. I came to the point where I couldn't put it off any longer though so I tackled it this past weekend.

I started by buying the HF touch up gun and a 10-gallon quiet compressor. I went with the touch up gun since I'd be painting a bunch of small, curved surfaces, and it also uses less air. I'm super happy with the compressor - 4.3 SCFM @ 90 psi was more than enough to run the gun, and it didn't scare me half to death when it kicked on like my old 6-gallon pancake compressor would. So nice to actually have a usable compressed air supply now. In traditional HF fashion the compressor has a quirk - it's super quiet while it's running, but it releases a burst of compressed air when it turns off which is crazy loud. It startled me the first time it did it, but it's still better than being loud all the time.

Because I bought a special edition Miata the paint is actually 3 stage - base, flake, and clear. I also needed to spray sealer as well since the primer I used was gray, so I had to spray a total of 4 layers. With 2 coats of each layer. Great first painting project, right? Supplies were twice what I was expecting, a little north of $400.

I'll spare you all the details of how the painting went, none of it was particularly hard, just time consuming. I painted the side skirts and mirrors since they were faded to basically white and didn't match the rest of the car. I knew they wouldn't match after fresh paint, but it's still better than being white.




Before: Photos don't show color well, but the side skirts and tops of the side mirrors were almost white. It's more visible when you compare the top to bottom of the side mirrors


When I took the side skirts off it became obvious how much the paint's faded over the years. I'd love to spray the whole car at some point, but that's way down the road.


Prepped and ready to paint


Sealer applied



After either base or flake, I can't remember




Finished! It's hard to capture how it looks in person, the last photo is the best I could get. There are definitely some dust specks in the engine bay paint, but the mirrors and skirts are pretty smooth. Which is fine, it's an engine bay after all, and it was my first time doing any painting.

If I ever paint again I'd definitely invest in a better gun and some better lighting. The touch up gun worked fine but it didn't hold very much paint, so I'd have to refill halfway through painting the engine bay. I used a headlamp while painting but that wasn't sufficient to see dust spots, I really should have had several shop lights so I could check from different angles. Overall I'm pretty happy with how it came out, it'll be interesting to see how different everything looks in the sun. I really like how orange-yellow the new paint is, the rest of the car is more of a pale yellow after all the sun fade. It's going to make me want to spray the rest of the car... but not until it's put back together.

 

I was initially planning on using AN hose\fittings for the fuel system like everyone else does but I changed my mind for three reasons:

• AN line and fittings are expensive, and (I think) it's overkill for this application
• The fuel tank, C5 fuel filter, and engine all set up to use SAE quick-disconnect fuel fittings and it feels silly to spend more money to convert everything to a different standard
• The SAE quick disconnects are actually pretty nice to work with - they just clip on. No need to use special wrenches and worry about rounding off aluminum hexes

For those reasons I decided to make my own nylon fuel line using Dorman fittings and fuel tube. All of the tube and fittings cost roughly $80, which is less than one AN line (the one from the back to the front of the car, ~$100). It won't be as abrasion resistant as an AN line, but with proper routing & strain relief it should be fine. A BOM for all of the materials can be found in my BOM spreadsheet

I used 3/8" line everywhere and used 5/16" quick connect to 3/8" tube fittings where applicable. The Dorman catalog was pretty helpful here, they've got a wide selection of fittings and rockauto has them for cheap. The tricky part is pushing the fittings on to the end of the tube. I followed this gude (more info here) and used a caulk gun to push the fittings into the tube. You're probably not going to get it by hand, even with heat.





This worked fine for not being the right tool. It was a little finnicky sometimes but it got the job done. If I were doing a lot more of this I would have gotten the Dorman tool (800-301), it's only $50.

The only real issue with using SAE fittings was the outlet of the C5 filter - it's designed to directly connect to a hard line with the SAE fitting. I found what should have been a good solution - Dorman sells 12" male-male fuel hard line which I bent at 90 degrees, pointing the outlet down the frame rail. This would have worked great had the line not been defective, the OD of the male connector was 0.010" too large. I noticed this when I tried to remove the quick disconnect and I had to pry it off. Disappointing, but the part was like $5 so I can't be too surprised.



I ended up buying some AN parts off of amazon and recreating the same thing for $16. Fortunately this put the outlet at about the same height as the bent line, so no further modification needed.



As you may have guessed by the previous pictures I mounted the fuel filter with a rivnut. With that located I was able to make lines from the tank to the filter. Heat was used to coax the lines into generally the right shape, then they were wrapped in rub-prone areas with abrasion resistant harness tape left over from the electrical work. The heat-and-bend method worked pretty well provided I didn't try to go too small with the bend radius, otherwise it would kink



The line between the fuel filter and flex fuel sensor is pretty boring, mostly a straight shot so I didn't bother to take any pictures. On the engine side I was hoping to re-use the FWD fuel pipe (it's different than the Camaro one) since it puts the connection vertical at about the right height. Unfortunately it interferes with the brake lines and I didn't want to risk bending it to clear since, if it started to leak down the road, the engine would have to come out to replace it. Better to just do it right the first time. The FWD pipe has the blue cap on it.



The pic below shows the Camaro fuel pipe, it's got the black cap on it. The issue here is that it's pointed in the wrong direction - the flex fuel sensor is on the lower drivers side of the firewall. Some amazon AN fittings later and it's pointed in the right direction





From here everything worked out really nice, there's a tapped hole on the intake manifold I used to strain relieve the fuel hose



With the fuel system done there are a few things to wrap up and then it's time to start the engine!

 

Wooo! Great work, looking NICE. That color looks so great all fresh in the bay, I could see how that makes you wanna repaint the whole car.

Stoked to see it runnin!

 

Put a few gallons in the tank, turned the key, and it started first try! No oil or fuel leaks, which was a relief. It even shoots flames.

 

Oh hell yeah, congrats!!

Gonna be a beast!

 

Congrats man! I can't imagine how motivating that is to get it fired up, especially with the engine seeming so happy about it. Can't wait to see this thing moving under it's own power.

I also appreciate the tips on the fuel lines. The nylon ones on the NB are such a pain to work with compared to the hose clamps on the NA's. I've debated on making some modifications to mine but didn't even consider that there would be kits to DIY them.

 

Thanks guys! I'm pretty pumped about it. The cooling system and exhaust are going to take longer than I'd like to finish up, but after that there's not much stopping me from driving it

I pieced mine together from the parts catalog, but it's all pretty cheap. The nylon stuff can't make tight bends but a few AN fittings make that fairly easy. The male fittings took a few tries to find, search for "6AN Male To 3/8" SAE Quick Disconnect Male" on Amazon.

 

As I alluded to in a previous post I wanted a way to monitor engine parameters in real time. With GMW8762 in hand I created a CAN database, which would allow me to decode the ECU's broadcast messages. I could have stopped here and just post-processed logs with my laptop, but if you haven't picked up on it by now I have a hard time leaving things alone. Instead of spending a reasonable amount of money for a real digital dash, I spent tens of hours writing a GUI in python to log, decode, and display ECU data in real time. Code is on github under pyCANdash. It'll display data in a few formats, but for the initial start I had the digital dash pulled up on a Raspberry Pi 5 with a .



It actually works pretty well, the only drawback is some parameters (like oil pressure) only get transmitted by the ECU every 500ms, so that gauge updates pretty slow. Otherwise it's totally usable as a dashboard from an engine perspective - it lacks "normal car" things like turn signals and a fuel gage, though. It'll do until I can get the factory gauges sorted out. The plan is to use it as the dash for the first few drives then relocate the screen to the center console, set it to default to the grid display, and keep it on board as a datalogger once I get the factory gauges working. I'm pretty happy with it for the $150 I've got into it.

 

I was getting tired of tripping over the rear subframe so I decided it was time to get it installed in the car. It's not a ton of work and it would be a nice morale boost to boot.

The instructions with the V8R kit said to angle the nose of the diff up by 1.5°, so the first order of business was leveling the subframe. I could have just zeroed out the angle finder on the subframe, but that would have made it difficult to get it level both horizontally and vertically (I'd have to un and re-zero it a bunch). Fortunately there are four screws on the underside of the subframe, which made leveling it super easy. I put blocks of wood under each screw to prevent it from tearing up my cart (too much)




After bolting up the rear mount I used a welding clamp to raise the nose up until it was 1.5° from vertical.



It was at this point I realized that the diff mounts V8R sent me were… odd. One of them had a jog in it such that when it was flat on the diff bushing there was about a 0.25" gap between the bracket and the subframe. This means that if I welded them in as-is, the opening between the two brackets would be 0.25" too small and I'd never get the diff installed. It's possible the stock diff bushing is shorter axially (I have the energy suspension one installed), but regardless I had to flatten it with a 3lb sledge and a wood block before it would fit properly. I also took probably a half inch off the bracket height so I had a chance of getting the welder in there. Welding went fairly smoothly and, I dare say, I'm getting a little better. Starts were a little cold but from what I've been told that's normal with MIG



While I was waiting for the paint to dry on the subframe I added a better diff vent since I've read these units like to puke oil if they're used on track. I whipped up a McMaster special with some oil-resistant tubing, a hose barb, and an air muffler. No the most lightweight solution, but it should work fine and it was easy to install



Once the paint had dried I reassembled the diff into the subframe, installed the axles, and filled it with oil. I've done it on my back enough times (once) to know how much of a pain that is so I made sure to do that before it went in. With that the assembly was ready to go in.



Installation was easy, if not a little sketchy. The whole subframe was balanced on a jack and raised into place - there's no way I could bench press that thing into place AND get a nut started. I definitely could have bench pressed it though. Definitely.



I also installed the front and rear shocks while I was at it - once I rebuild the rear hubs it'll be ready to go back on its wheels which is exciting. It's starting to look like a car again! I tried to also install the driveshaft but unfortunately the one V8R sent me is about an inch too long - I emailed them and we'll see where that goes. I've got friend with a lathe as a backup plan - there should be enough meat on the drive shaft adapter to make it fit.

 

The cooling system has been a decent amount of work, so let's start with the heater core. I chose to replicate the V8R kit and route the coolant between the engine and the AC lines on the passenger side. There's not a ton of room …anywhere along this route, but it all clears. Since I did this work out of order I'll just present the finished product, starting at the heater core. I cut the heater core pipes and added flares using modified HF crimper pliers. This worked pretty well, but I can't claim the idea was mine - I stole it from here. As long as you break the tool's edges with a file and go slowly it produces decent looking beads.





I didn't take any pictures of the core without hoses attached, unfortunately. I was probably so pissed at the stupid V-bands holding the heater pipes on that I forgot. Seriously, those things took like 30 minutes to get on and I cross-threaded one of them in the process. And it was on my workbench, not in the car! Anyways, once those were attached I trimmed and secured 2x gates 28469 molded heater hoses to the heater core with powergrips. On the other end are hose barb to -10AN fittings with -10 couplers



Those -10 couplers attach to right angle bulkhead connectors which protrude through two holes I drilled in the firewall. I was worried about the length of the fittings so I located the pass-through holes as far outboard as possible - the firewall bends in towards the center of the car, so if the fittings are too long none of it will fit. This means that I did not offset the holes like most people do, figuring it would be a problem for "later me".



Unmodified, the bulkhead fittings stick pretty far out into the engine bay. I had access to a lathe a few months back so I made some spacers to pull them more towards the interior, they're visible in the image below between the fitting and the firewall.



Clearance is clearance, right? Below is the view from the engine bay side, and the second image shows why I wanted to pull them in - the hoses have to make an almost immediate 90° turn down, then 90° towards the car's centerline to get to the heater pipes (bottom two ports).





This image makes it look like there's a lot more space than there is - you can sort of get your hand back there, but you basically have to guess what you're doing since it's covered from the top. The more astute reader may have noticed that the bulkhead fittings were both blue in the first image and are not the same color in the rest of them - let's just say I learned a hard lesson about unlubricated, dirty aluminum threads.

On the engine side I used the Cadillac part that others have used, GM 12644554. It gets you about 90% of the way there but it needed some tweaking before it fits. Here's how it looks straight out of the box:



The smaller (5/8") tube fits perfectly, but the larger (3/4") tube causes some issues. This is after I'd bend the lower tube forward some - notice how it wants to occupy the same space as the FR brake line.



There's not a ton of options here, the only solution that made sense was to bend the brake lines as far up as I could and angle the large tube down. I cut the brace between the pipes and made a few slits on the lower left side using my band saw. Once I verified that everything cleared I TIG'd it back together, leak checked, and painted it.





The lower heater hose clears… sort of. It rubs on the transmission bolt, but I don’t really have many other options (besides freezing in the winter). I'll wrap it in some of the abrasion resistant harness tape but I'm guessing it'll be fine - it'll most likely move with the engine, so there shouldn't be a lot of rubbing going on.

Remember how I didn't offset those bulkhead fittings? This was now a problem for "present me", not "later me". Fortunately it wasn't too difficult to solve, and I was able to offset the hoses fore\aft instead of side by side. Amazon has a large selection of any kind of AN fitting you could ever want, which is super handy. They're also made of what feels like hard chewing gum, which is not cool. The price and delivery speed are right, so I went with it.



The bottom hose uses a tight-radius 90° fitting with a hose barb fitting, and the top uses a -10 AN extension with a large radius fitting.

The top (smaller) heater hose wasn't an issue to source - it's the same gates part as I used on the inside. The lower hose was more difficult because -10 to 3/4" hose barb fittings aren't a thing. I'm guessing GM used two different hose sizes to mistake-proof assembly, but it does not make this application very easy. Luckily gates makes exactly the hose I needed (18072) - it's a right angle and has a 5/8" ID on one side and 3/4" on the other. Their catalog is super helpful for stuff like this, it's worth checking out if you're in a similar situation.

There's one (and only one) way to assemble all of this, including the radiator pipe (visible in the last photo). I'm pretty sure there's close to an 80% fill factor in this area, it's crazy how little room there is left. Hopefully none of it rubs and causes a leak, but time will tell.

 

Really clean work sir. Doing the lords work AN'ing what you can.

 

Your post is perfectly timed! I'd seen the crimp tool modified like this before before but wasn't sure how well it would fit in the small heater pipes. "Put heater pipe in car" is now scratched off my to-do list. It's replaced with "Buy 9 1/2 HF crimp tool". Thanks for sharing, both to you and Gooflophaze!

 

Cooling the engine turned out to be a little more difficult than I'd anticipated, although pretty much all of the added difficulty was due to my desire to do something different and "save money". The track proven (and well documented) path is to use a supermiata radiator and buy an off the shelf header tank. I did neither of those things and ended up spending more money.

Instead, I bought a 600hp-rated Griffin universal radiator and made my own mount, fan shroud, and header tank with some help from sendcutsend. Was it technically the right path? Absolutely not. It was pretty fun though and I got to practice some aluminum welding and fabrication techniques. And that's the point of this project, really.

Anyways, we'll start with the radiator. I bought it on black Friday sale for $340 shipped, which is pretty good considering it's about 21 lbs of aluminum. It's the right size, the inlet and outlet are on the correct sides, and the only modifications I'd need to do is to remove the radiator cap and attach the fan shroud.



I started by figuring out how to mount it. The instructions recommended supporting it all the way across the bottom and I wouldn't mind having some protection from road debris \ off-roading at the track. I'm quickly learning how expensive metal stock is (thanks tariffs!) so I hit up my local scrap yard to see if they had anything that would work. I lucked out and found some 3-5/8" x 1.5" x 1/16" aluminum channel that was exactly what I was looking for. $6 and a few hours later I had something passable





I ended up having to enlarge the shroud-side cutout, but otherwise it worked as-is. Next I needed something to attach this to. The stock radiator is supported via two posts which fit into the lower radiator support, meaning there were holes exactly where I wanted to put nuts. It just so happened that the blank left by one of my hole saws produced exactly the right sized donut to fill it. I added a cutout to let water drain, tacked the donut and a nut in place, and I was in business





It looks like it's crooked in the above image but in reality I had the sway bar off by one hole. I then turned my focus to finding\attaching fans to the radiator. Griffin will sell you a shroud and fans but they mark it all up by about a factor of 2, plus I wasn't a huge fan of how they mounted with self-tapping screws. After measuring several times I drew up a shroud in Onshape and sent it off to sendcutsend. I can't overstate how powerful and cheap this combination of tools is - Onshape is free and is completely web-based (my 10 year old laptop can run it in a browser) and sendcutsend's mission is to sell you laser cut parts for the same amount as the raw materials would cost you. The shroud with bends and PEM nuts inserted was $75 shipped. I'm a fan.



The corners were so accurate that I didn't need filler to weld them together, running the torch over them was enough. I positioned the shroud on the radiator, attached the tabs with some 0.020" Lacroix-brand shim stock between tab and shroud, and welded the tabs on. I won't pretend like these welds are pretty but for my first time welding tabs on it didn't come out too terrible.





I added a 1/8" NPT bung in the top right in the event that area traps air - I doubt it, but it was $8 for 2 on Amazon, cheap insurance. Also note the gray mounts below the fans - these are to hold the fan-side Deutsch connectors (not pictured) in place, securing the fan harness to the shroud when everything is connected. It's a little detail but something I'm sure I'll appreciate when I'm playing service technician.

I then needed to chop off the radiator neck and fill it in. This was one of my less OSHA-approved operations, but it worked. The shop vac blew air into the opposite port to prevent the radiator from clogging and I held the radiator while the band saw chewed through the neck in horizontal-saw mode.



It worked so well that I actually cut between the neck and the radiator. This was more luck than skill but still pretty cool.





When I put in the shroud order I slipped in some blanks to fill the neck hole. Unfortunately the welding didn't go as smoothly as I'd hoped - I was afraid of blowing a hole in the 0.060" end tank so I didn't use enough heat, making the weld narrow and tall. Which meant I needed to put beads on either side of it. It just looks like a mess now, but whatever. The point is to learn and I'd be very surprised if it leaked with how much filler I added. At the same time I also welded some 0.5" diameter aluminum studs to interface with the factory radiator mounts.

The bottom of the radiator is supported via 3 layers of adhesive-backed foam. I also added some edge trim to the bottom edges in the event the foam compresses - even if it does, it'll still have some support on the ends and in the middle. Foam was added in the U-channel to support the radiator fore\aft



And finally, a picture of the finished product:





I still need to get some tubing for the top posts, but otherwise it's mounted. If anyone is still reading this apologies for the book, there ended up being more here than I was expecting. I'll write up the engine side of things and the coolant tank in separate posts.

 

The engine side of things was a little more straightforward once the radiator was in place, it was mostly just connecting the dots. I started with the (upper) engine outlet which points forward and is roughly centered on the engine. This poses two issues: There isn't a ton of room to route it to the radiator, and the air intake needs to occupy the same space.



It was at this point that I started kicking myself for not just using a Miata radiator. This was not the first (or last) issue caused by the Giant Radiator of Inconvenience. The solution was fairly straightforward, if not tedious - cut the manifold after the first 45° bend and weld on a tube bent at 45°, making it parallel with the radiator.



The tedious part was getting the round tube to line up with the rectangular manifold. At first glance I thought this wouldn't be too bad - just squish the tube until it's about the right shape and weld it up. In practice it was a lot of cutting, bending, annealing, fit-checking, and repeating. Since I'm not super experienced in welding aluminum I wanted to make sure there were minimal gaps. After a few hours I finally got something that was acceptable



This weld made me a bit nervous due to both the extensive prep time and the difference in material thicknesses. Luckily the weld wasn't as difficult as I was anticipating, I kept the torch mostly pointed at the cast part and added plenty of filler to keep things cool.



Most of my aluminum experience at this point was laying beads on flat plate (in the community college course). Given my total lack of experience I was happy with how this came out. I ended up going over it a few times to make sure it wouldn't leak, but otherwise welding was pretty uneventful. I later realized that this hose routing precluded the use of the factory PS reservoir which isn't a huge deal, but it did emphasize how one design decision (radiator) cascaded to a lot more parts than I'd initially thought.

The lower hose little less straightforward given how little space there is and the fact that the rad outlet was 1.75" and the engine inlet was 1.25".



After a lot of searching through parts catalogs I came up with a plan - Turn the radiator outlet 90° using a , turn it another 90° using a 1.25" aluminum mandrel, and modifying the engine inlet to match. After some arts and crafts it looked like this would work.



This site has been super helpful for making 3d tube mockups. It's really intended to make templates that you'd trace onto metal, but it also doubles as a paper prototype. Parts were ordered and the lower tube was modified:





I did check for belt clearance, the serpentine goes from the bottom of the alternator to above the top of the crank pulley. With the radiator mounted and plumbed the last piece of the puzzle are the header and overflow tanks. In keeping with the theme of "why buy for $100 what you can make it for $150" I decided to build my own, but that's a story for another post.

 

There's really only one place to put the coolant header and overflow tanks - by the firewall on the passenger side. Given the space constraints in that area (firewall connector, AC lines, shock tower) it would have been tough to fit an off the shelf combo unit. Plus I wanted an excuse to try out a few fabrication techniques, so down the rabbit hole I went.

I started by purchasing a scan of the whole chassis from left lane designs (@Padlock ) and importing it into OnShape. Because the scan is fairly detailed and OnShape is… free software, it chokes when viewing the whole chassis. First order of business was to section off just the corner of the engine bay I was interested in, then draw up the windshield washer bracket that I'd be mounting to.



This is the first time I've worked with a high quality scan and I've got to say, I'm impressed with both the scan quality and the options it opens up. This (or any other 3d scan) isn't going to show you exactly where every bolt hole is, but being able to design around existing structure in CAD is SO much easier than messing around with paper templates. I started by drawing up the general shape I wanted



It's hard to show in one image why this is the shape it is. On the left side is the firewall connector which necessitates the 30° chamfer to clear the harness. The cutouts on the bottom are obviously to clear the shock tower, and the depth (towards the engine) is dictated by the AC lines. The solid is simply the space that's left.

The tank is split into two sections: the header (pressurized, right) and overflow (left) sides. Right side will get a and the left side will get a . I was initially planning on reusing the radiator neck I cut off, but it turns out there's two sizes of radiator necks: 1-1/4" and 42mm. I had the larger, which unfortunately didn't fit very well in the space available. Plus a new neck was $14 - how anyone is making money on that part beats me.

Anyways, this is the point at which I got really impressed with how easy it is to make things out of sheet metal. Without going into all of the details, it could take a few hours to go from the image above to something I could send off and get made. In reality it took longer since I was learning, but if I did this again I could go from concept to hitting order in an afternoon.





All of those finger joints are made automatically - just click on an edge, configure the joint, and both faces are modified. This includes the tank divider (blue part poking through). Doing all of that manually is what has steered me away from doing something like this in the past, it's super time consuming. That, and I didn't have a welder. Details.

Holes on the vertical parts are for 1/8" and 1/2" NPT bungs, with the left set of holes being for steam in \ coolant out and the right side for connecting to the radiator overflow port. The tricky part with this design is how to seal the pressurized and non-pressurized halves from each other. I tried to get clever and break the divider corners out such that they sealed when welded on the outside, avoiding a difficult inside corner joint weld. In practice this didn't work all that well, but that was the idea.



I hit order on a Friday afternoon and parts showed up on Wednesday. I threw in a bunch of weld coupons with the order since I've never welded thin (1/16") aluminum before and I'd rather mess those up than my part. Total for 2 tanks, 35 coupons, and mounting tabs was $103 after a 15% off discount.



Fit-up on the laser cut parts was awesome - I removed the dross with a file, cleaned the edges up with a wire brush, and it all just fit together like a puzzle. The first two parts were a little tricky to get aligned but after that it was a cake walk.



I'll spare you the horrible looking practice weld coupons and first tank, below is the finished tank.





Welding wasn't as terrible as I thought, although I did learn the importance of keeping the torch a consistent height. I was initially trying to control the puddle with heat input alone which turned out to be a mistake - the torch would drift up too high and put a ton more heat into the part than expected. Once I figured this out (on the last panel, of course) things started going a lot smoother. The welds definitely aren't the prettiest but I'm happy with how it turned out for my attempt at welding thin aluminum.





From a design perspective I now see why there aren't very many divided tanks on the market - the "make the inside an outside corner" joint failed miserably and I had to end up welding the full inside seam anyways. Divider aside I'm super pleased with how this came out, it occupies the minimum space necessary and performs both functions I wanted it to. Definitely going to be using this technique for other parts in the future.

 

A quick detour from car-related stuff - I'm taking a metal fabrication class at my local community college which concludes with a personal project. I wanted to build something that made good use of the college's tools as well as something I'd find useful. I settled on a fixture table - I've wanted one for some time now (my current welding setup is an aluminum plate and some sawhorses) but haven't had enough of a need to spend the $500 - $1k to buy one.

What makes this possible is the 4'x8' CNC plasma the school has, it allows me to use the same tab and slot technique from my coolant tank but at a much larger scale. I didn't come up with this idea - I took significant inspiration from this table, and chose the 24x36" size because two tables (barley) fit on a 4x8 sheet of steel. A few hours in CAD and I had this:



The full (editable) solid model is located here in case anyone wants to make something similar. The table dimensions are variables, so if you want to make a larger or smaller table the model will auto-update. What's interesting about the tab-and-slot tables is that the flatness is derived from the substructure, not the material itself. IE, even if the top has a slight bow to it, when it gets clamped together and welded the substructure keeps it all flat. Or at least flat enough for what I'm doing.




Everything barely fit onto the plate, there ended up being about 0.25" part-to-part and part-to-edge. Because machine time is free I ended up just paying for material - $250 for the 4x8 1/4" plate and $55 for the 1.25" square tube. After tax and paying the supplier to shear the plate into thirds the total was right on $350. Considering two tables + legs would easily be $2k+ if I were to buy them, I'm pretty happy with the cost.



I got some strange looks picking up 1/4" plate in an SUV but it all fit - the plate in the back and the tube (cut in half) sticking out the window.



Turning my flat pattern into G-code was a bit of a task because, as it turns out, there are some specific techniques needed to make round-ish holes on a plasma table. There's not a lot of free, feature rich software for creating toolpaths (no surprise there), but after some searching I found that Fusion360 would do the trick and it's free for personal projects. I thought this would take maybe an hour, but it took like 4. And this is just a 2D part! I have a new respect for people who run CAM.



This covers from January to where I was as of last week, I'll cover fabrication in another post.

 

Awesome to see my scan be put to good use! Love it (& thanks for the support)

Nice work on the divided tank assembly, but I have one question. How are you venting the overflow tank half of the assembly? Did I miss something? The filler cap that you used doesn't appear to be a vented one based on the shared link, and that side of the tank needs to be vented to atmosphere somehow in the event of an overheat scenario to give coolant a path to escape the system safely.

This is just me raising a flag based on experience, but at glance based on the photos, the overflow looks like it's probably sized a little on the small side for the cooling system volume you may have with that engine and large capacity radiator. A good rule of thumb is to expect your coolant to expand by 7% from a 70F cold to 220F hot operating temp swing. A quick google search shows a stock LFX system on the camaro holds 11.6qts. 7% of that is 0.8qts (27oz), so that's implying that if your system was completely full when cold with 11.6qts that up to 0.8qts (11.6 x 7%) could move into your overflow reservoir once the engine is warmed up. There's a reason OEM overflow bottles are so freaking annoyingly large. I could go down a horribly boring engineering brain dump of fun that I've had studying this over the last few years, but if you are undersized on overflow bottle size, you run the elevated risk of it overflowing the reservoir from the vent (when up to hot temp) and/or pulling air back into the pressure system upon cooldown (because there isn't enough coolant volume to pull back in from the overflow).... Anyway, might be worth a quick check on that to see how close you are to this 7% (27oz) ballpark. Grab a beer can and see if 2 full can's worth (24oz) can fit in that side of the tank assembly.

If 2 full cans of fluid fit on that side of the tank, I'd be feeling okay about it. If not, pay close attention to it during heat cycles knowing the risks I mentioned could become real.