That's hardly "major" surface rust.

As I recall, pulling up the tar didn't reveal much more rust in the Cosmo I already didn't know about. What really showed it was the media blasting. The media will find any little weak spot and basically blow through it. Which is a good thing of course, because then it will get repaired instead of skipped.

In your case, if the rest of the car looks clean, I'd just wire brush the area down to bare metal then apply some POR-15. The seam has already begun to rust in the joint, but there is nothing you can do without disassembling it. Treat the surfaces you can see, then have Krown or something similar applied to the other side so it can wick up into the joint.

 

Similar question on my Cosmo.

The factory undercoating has seen better days and is flaking off everywhere. there is some surface rust just starting where moisture has crept up under the coating. Nothing a wire wheel cant remove but i'm looking for suggestions on how to reseal the complete underside and inner fenders.

Now would be the best time for me to accomplish this as I've removed the transmission to fix a leak and I've also removed the rear end to replace all bushings.

What will you be doing to seal the underside of your Cosmo? Similar wire wheel/POR-15 approach you used on Tina?

Not looking forward to a POR15 application on my back under the car!

 

While I'm done with air conditioning, part 32 of my '76 Mazda Cosmo restoration still deals with moving air around, as I fabricate a cold airbox. After working so long on the Vintage Air system I wanted to do some simple fabrication, so the air box was a perfect choice. Made to accept a cone filter it is a true cold airbox that draws air from the inner fender. So not only will the box muffle the sound of the engine but it will also assure the turbo is drawing in the coolest air it can. Since I was in an aluminium fabbing mood after the airbox, I also continue on and build an aluminium coolant recovery bottle. Fitting perfectly in the little space between the radiator support and relay panel, made out of square aluminium tubing, it provides a hidden and elegant solution while not taking up any engine bay space. Included in this episode: making cardboard templates, cutting aluminium, bending/shaping aluminium, loads of TIG welding, nutserts, cutting tubing, fabbing a tank, welding bungs.

 

Curious question after watching your latest vid Aaron: Do you plan on adding some way to monitor fluid levels in the overflow tank you've made?

 

I haven't done anything about monitoring the level in the recovery bottle. If I have to check, just a quick removal of the cap and a peak inside will do the job.

Now I did forget to include a low coolant sensor when I installed the radiator. It's on my list to pick up an FC low coolant sensor and weld a bung onto the rad for it on the passenger side.

 

Another great video, Aaron, love this thread!

Couple questions:

1. How do you get your camera to fade to black just before you start to weld?

2. Why didn't you use some sort of weather stripping or sealant on the air box lid.

3. Why did you go with the $80 silicone L rather than an aluminum L and two straight silicon couplers? Wouldn't it be cheaper and easier to install/remove?

3. I love the engine bay fabbing, but when do you plan to get to suspension and brakes?

Once again, fantastic build!

Devan

 

It's all in the editing. I start the camera to get a few seconds of the area to be welded. Then with the camera still running I slip the welding lens over it. This may take several attempts as the rig which hold the lens may press a button or two on the camera. Then I begin to weld.

In editing, I just cut in a few seconds of footage of the weld area, then fade out the video, and cut it so the welding under the lens starts a second after.

I didn't much care about it being 100% sealed at the top. Any engine bay air being sucked in from the top is going to be tiny compared to what the filter draws in from the bottom. However upon final assembly I may stick a rubber strip to the lid to assure a better seal. Oh, and to prevent rattles.

An aluminium bend wouldn't have enough flex to allow the engine to move on the mounts. I'd expect an eventual failure due to cracking at the airbox or the silicone couplers to tear. Hump hose couplers would solve that issue but probably cost about the same as the big silicone bend.

That's the second question numbered "3".

It will soon come the time when I must stop putting off the suspension/brakes and actually do it. I have been putting it off, mainly because it's the only area of the build where I am still trying to figure out what to do. My original plan was to use a 2nd gen subframe but there is interference everywhere. I won't be able to mount the steering rack in front of the subframe like the 2nd gen. So it may be a mixture of 2nd gen parts and Cosmo subframe. Then again, maybe there is a generic hotrod suspension which can be adapted? Many questions still up in the air.

 

Haha, I guess not. Clearly a difference in geography affects what we call "major" rust. There's a bit more pitting than I would like to see, so I'm going to pull up the tar and clean the whole section before I POR-15.

As usual, another great video. I love the stealth, out of the way placement of the coolant overflow bottle.

 

Oops, my bad.

 

Part 33 of my '76 Mazda Cosmo restoration deals with what I would consider to be two important, though miscellaneous, tasks. While waiting for the intercooler parts to arrive I tackled what I thought would be a quick and easy job; building a turbine heat shield. I won't admit how long it took but suffice it to say that the intercooler supplies not only did arrive during the heat shield build, but were also packed away under the car and began to grow shop dust. Regardless of the time it took I must say I'm quite happy with the heat shield as I've seen very few like it. So many of the turbine heat shields on the market are nothing but a bit of bent sheet metal and a mounting bracket. At that point I decided I may as well deal with another small job so I took the time to remove excess OEM equipment from the throttle body and eliminate all the unnecessary vacuum nipples on the upper intake manifold. Included in this episode: turbo turbine heat shield fabrication, turbo assembly/disassembly, template making, stainless steel sheet metal cutting/drilling/grinding/bending, TIG welding stainless, OEM intake manifold extra nipple removal, TIG welding aluminium, FD throttle body simplification

 

Another great video, Aaron. Have you considered adding insulation to the inside of the shield?
This stuff is pretty amazing and for the price worth a shot.

McMaster Ceramic Insulation

 

Awesome video man! Cant wait for more aye

 

Need something to watch while I work, Post another vid. Thanks

 

It's time for part 34 of my '76 Mazda RX-5 Cosmo restoration. This time, I'm installing the water to air intercooler. I've installed and fabricated plenty of air to air intercoolers in my time but never a water to air unit. I chose to use water to air on the Cosmo because it meant that I could keep the piping as short as possible for the best boost response and because of the limited amount of room to run charge piping out to the front of the car due to the large rad and A/C condenser. It was definitely a learning experience for me as I underestimated the amount of time needed to fabricate all of the components. Thus, I have split the episode into two parts. In part 1 of the installation, I fabricate a throttle inlet adapter to fit the FD throttle body, position and mount the intercooler, build charge piping, weld on a BOV flange and IAT bung, fabricate an aluminium water tank with inlet/outlet/fill bungs and mount the heat front heat exchanger.

 

love watching your video's don't forget safety glasses.

 

Did I not wear glasses?

I usually don't when sawing or drilling aluminium.

 

Always so much entertainment watching your videos. I don't watch tv only movie night with the fam and most of the time checking your videos out and others.
Thanks

 

In the last episode of my '76 Mazda Cosmo restoration, the basic components of the water to air intercooler system were laid out along with the considerable amount of fabrication needed to build the throttle body inlet, intercooler piping and water tank. As well as mount the heat exchanger and BOV. In part 35, we finish up the water to air intercooler installation by taking care of mounting the pump, plumbing all the water lines and wiring up the system. Additionally support brackets are built to support the piping. Lack of space meant I had to get creative with pump position after accidentally creating a clearance issue with the water fittings. However once mounted I was very happy with pump position and the plumbing was straightforward. Included in this episode: Cutting/grinding/drilling aluminium, making aluminium brackets, assembling AN house and fittings, wiring relay to spare Megasquirt output, adding temperature sensor to Megasquirt analog input, plumbing air to water intercooler with tank and pump, TIG welding brackets.

 

Sweet birthday present for me, a fresh new video for me to enjoy! Loving the build, Aaron.

 

Holy ****! It worked!"

 

I was surprised that you couldn't open up the MS3 pro case and install a bias resistor like you can on an MS3x card. I actually removed the auxiliary guages I was running in my FC and put in two pressure transducers for oil and fuel pressure and a GM temperature sensor for oil temperature.

I'm currently using a Nexus 7 tablet running Shadow Dash MS with a matte screen protector and a removeable car mount. The datalink is bluetooth, but it'll work with a USB-to-RS-232 serial adapter connected to its OTG port (stock kernels don't support OTG and charging at the same time). The only downside is that on sunny day, the display is unreadable if you're wearing sunglasses.

But, for $25/sensor and $170 for a refurbished tablet and a few accessories, it's a pretty decent customizeable dashboard display/datalogger. I'm still running the stock instrumentation (actually, I'm switching back to astock instrument and warning cluster) and plan to keep the tablet removable. It's a lot more convenient to use the tablet to log data than the MS3's onboard datalogger.

 

It struck me as a bit odd as well that the MS3-Pro didn't have pads for a bias resistor or a jumper selectable bias resistor. It's not exactly elegant to just stick a resistor into the harness but there are few options.

With the newest MS3/MS3-Pro firmware having the actual gauges is less important as there are now settings for low oil pressure actions, etc. I have one analog input left which will go to an oil pressure sensor for this purpose.

 

With any rotary, a robust fuel system is a critical component in reliability. This is what will be covered in part 36 of my '76 Mazda Cosmo restoration. In this episode I set up the engine bay section of the fuel system. This includes the regulator, fuel Y block, and all the fuel hoses using braided line and AN fittings. I also bend up a set of stainless fuel lines for underneath the car. The fuel tank also needed some attention so I begin the process of getting it cleand out and ready for modification to handle an in-tank EFI pump.

 

Awesome video man, funny as he'll too . Thanks for this video since I'll be doing this to my RX7 first gen . It has a Carb turbo set up , and previous owner my cousin did kinda a half job and never finished. I got a fuel line I believe 3/8 a Bosch .044 fuel pump , got a relay for pump since he didn't have one before And fried aeromotive a1000 pump. I got a fuse , toggle switch , full regulator but will I need a fuel y block ? Or just single do ? I been researching a lot and it confuses me .
Thanks sorry for confusing reply

 

The fuel pump should always be run from the EMS fuel pump trigger wire, never a toggle switch. The switch is deeply unsafe should you be in a collision.

You don't need the Y block if you run the fuel rails in series like Mazda did. The Y block is just for us who convert to a parallel rail system.