Build Another Prado in Montana

[AirheadNut]

After some late night research last night I think I have a solution for the heat exchanger problem. Came across a post on a Honda forum where someone mentioned using the radiator from a Smart car in a custom w2a setup. They use crossflow radiators a little bigger than 16"x16", with a 7/8" thick core and 1-1/4" inlet/outlet. If it can cool a 1000cc engine it ought to be sufficient for my application.

 

[svsisu]

After some late night research last night I think I have a solution for the heat exchanger problem. Came across a post on a Honda forum where someone mentioned using the radiator from a Smart car in a custom w2a setup. They use crossflow radiators a little bigger than 16"x16", with a 7/8" thick core and 1-1/4" inlet/outlet. If it can cool a 1000cc engine it ought to be sufficient for my application.
View attachment 4146087

So freaking cool, outside the box thinking. Hope it works out!

 

[AirheadNut]

Had to make a modification to my ECU mount, added a fourth mounting tab to take some wobble out of it.

Got everything painted up and installed, pretty happy with how things are fitting. I put some adhesive backed foam on the ECU mount plate and the aluminum bracket to both cushion the ECU and provide some grip so it can't move once the bolts are tightened down.

Toward the end of the evening I started laying out the wiring harness in the engine bay to get an idea of how it will all fit. Most of it looks pretty good but I'll have to take a fair bit of length out of the main harness coming out of the ECU, it is about 8-12" too long in stock form.

 

[AirheadNut]

More work on the wiring this evening, though not a lot got done since I kept getting rained on. I sourced a couple of harness connectors from Corsa-Technic that will allow me to connect to the throttle pedal and OBD harness left over from the last swap. The Passat this engine came from used a CAN-Bus system to communicate between the ECU and gauge cluster, so if I want to get usable signals from it for the glow indicator, tachometer and other gauges I'll need to get a signal converter. Fortunately Fast Forward Automotive in BC builds a unit that does just that specifically for TDI swaps.

I also talked to a EE at work and he said it shouldn't be too difficult to build a signal converter to run my tachometer. All the converters I've seen go from the stock style signal (variable voltage zero crossing sine wave) to square wave. I need to go the opposite way to run my stock tach.

 

[AirheadNut]

Made some good progress on the harness this evening. I discovered that if I put a sort of zigzag loop in the main harness I can get it to fit nicely without having to shorten the whole thing. It should all tuck away cleanly under the coolant reservoir and be pretty much out of sight.

There were some damaged wires in the harness, it lived a rather hard life in the junkyard apparently. Two were broken and two smashed, so I spliced them together.

I capped off all the cut wires from the ECU plugs to make sure they're all weathertight. Heat shrink crimped with pliers while still hot works pretty well.

3M Temflex 1755 friction tape is a pretty good replacement for the stuff VW used on their harnesses, it is quite sticky and a bit of a pain to work with but the results are worth it. Got the ECU plugs all buttoned up, unfortunately the tabs that hold the cover on the smaller one are broken off one side, so it isn't as secure I'd like it to be.

With the ECU installed facing the opposite direction I had it at first the harness routing is much better.

 

[AirheadNut]

The ALH harness had a connector and separate loom for the OBD and throttle pedal, after some digging I identified it as a Molex MX150-series 16-conductor connector. I bought both a male and female connector with an assortment of pins for different wire sizes, that way I'll have the male connector for the ALH harness when I end up installing it in the snowcat someday.

 

[svsisu]

Nice work!

If you are not familiar with it- Tesa tape makes a good wire harness tape that is pretty user friendly, affordable and available at many online outlets.

tesa® 51608 PV0

PET fleece tape for flexibility and noise damping

www.tesa.com

 

[AirheadNut]

Nice work!

If you are not familiar with it- Tesa tape makes a good wire harness tape that is pretty user friendly, affordable and available at many online outlets.

tesa® 51608 PV0

PET fleece tape for flexibility and noise damping

www.tesa.com

Yeah, it turns out that is likely what VW used on their harnesses. I'd heard of it before but didn't remember the name when I was looking for that kind of tape, and for some reason it never turned up in my searches. The 3M stuff is more expensive, but it is pretty nice and should do the trick.

 

[AirheadNut]

More intercooler and charge pipe stuff arrived, as seems to be normal with this swap things didn't fit like I expected. The current plan is to put the intercooler between the fan shroud and timing cover, leaving good access to the fuel filter.

The turbo outlet sits at an odd angle, I couldn't find any silicone elbows that would work so a pie cut pipe was the only alternative. I sliced up some of the excess length on some of the other aluminum tubing I ordered.

Next up is figuring out a way to get around the battery and connect up to the 45º pipe going around the side of the engine. I think some more pie cuts are going to be the ticket.

 

[AirheadNut]

Made up a rail to mount all the necessary relays for the engine: starter, glow plugs, ECU power, injectors, lift pump, radiator fan and intercooler pump.

It started to rain pretty heavily this afternoon, so I shifted to indoor work. Using 2.75" tubing for the inlet and outlet on the air filter housing, had to get a little creative with the fixture plates to get everything in position and tack it together.

I took the opportunity to fill a few holes and clean up a couple of the welds on the air box lid while I was at it.

 

[AirheadNut]

Yet more delays on parts. The Smart car radiator arrived damaged, both inlet and outlet mildly crushed and the whole radiator bent out of square. I sent it back but it will probably be at least a week before the replacement arrives.

This evening I worked on mounts for the intercooler, there is not much for solid mounting points in the area in front of the engine. I'm planning to put a couple of brackets on the back of the fan shroud with a sort of cradle setup to hold the body of the intercooler and large hose clamps to secure it. Got to try out my shrinker-stretcher making the cradles.

Made a little modification to my tube beading die for the bead roller, the outer die had very sharp edges which formed a nasty burr on the bead. I put a slight chamfer on the die with a Dremel, it is better now but needs more of a fillet with a larger radius.

 

[AirheadNut]

Work continues on the intercooler mount. After looking around at the engine some more I figured out a way to cantilever the mounts off the engine rather than the fan shroud. It should be much sturdier than mounting to the fan shroud.

Clamps have been added to the air filter housing, they seem to work pretty well but I have yet to test the effectiveness of the seal. One of them interfered with the windshield washer reservoir, so I had to drill out the rivets and move it slightly.

 

[AirheadNut]

While I had the air filter housing all apart I hit some of the welds with a dremel to smooth out the sealing surface on the lid.

Progress was made this evening on some of the charge pipes, I'm still waiting on more aluminum tubing to finish connecting the intercooler outlet to the intake manifold.

The modification I made to the tube beading die really seems to have helped, the beads are turning out smoother and more consistent now.

 

[AirheadNut]

I wasn't happy with how rigid the intake from the air filter to the turbo inlet was, so I shortened the air filter outlet tube and added in a hump connector. Not sure it made much difference but hopefully there isn't a ton of movement between the engine and body.

In an attempt to determine if my home-brew air filter housing flows well enough for the engine I picked up a Donaldson Informer, I'll have to hunt up a 1/8 NPT aluminum bung to weld on to the filter housing to attach it.

Threw a few coats of paint on the intercooler mounts and installed them. I have a sheet of adhesive backed foam left over from a project years back so I used some of that to provide a cushion and some grip on the intercooler body.

 

[AirheadNut]

The intercooler fits nicely, not sure if I want to keep with the worm drive clamps or use something a little more elegant.

I had planned on wrapping up the intake tract this weekend, but the postal service was 4 days late with my aluminum tubing (so far!). I pivoted to working on the engine electrical harness. I started by putting together the engine relay harness: ECU power, fuel pump, intercooler pump, glow plugs, radiator fan.

Next up was the throttle pedal, CAN-Bus and OBD harness, I was able to get it fished through the firewall grommet.

Things are somewhat tidied up, just need to get some 8ga cable and a few other terminals so I can hook up the glow plug power and then I'll be able to wrap everything up.

 

[AirheadNut]

Progress on the charge pipes this evening, I finally got another piece of aluminum tubing to arrive in the mail (the first is still lost in the USPS sorting office in the next town over). Originally the transition from the intercooler to the main charge pipe along the LH side of the engine was going to be pie cuts, but I had two 90º bends left over and discovered that they were just right when trimmed back a bit.

As usual it took a lot of fiddling around to get everything lined up and oriented the way I wanted but in the end it all fits nicely. Adding the MAP sensor port was more difficult than I anticipated, it really didn't want to weld nicely.

The only thing left to do is add some mounting tabs and put a bead on the MAP sensor end of the tubing. Unfortunately I got carried away when welding everything up and forgot to bead that part by itself, it will probably be a two person job now.

 

[AirheadNut]

Some cool stuff happening! I recently learned how affordable metal 3D printing has become, so decided to explore some options for making coolant adapters and fittings. My radiator has 1.5" inlet/outlet ports, and the VW coolant pipes are basically 1.25", so I'll need some adapters. For the upper hose a sharp 90º down to go under the intercooler would be ideal, as well as incorporating a bleeder nipple near the top of the system to help pull any air out of the system into the coolant reservoir. I drew up a quick and dirty CAD model with the basic size and dimensions and got a quote to have the part printed in 316L stainless steel: $73.48 delivered to my doorstep. This opens up way more possibilities for oddly shaped hose adapters and manifolds, I am going to have to reevaluate my cooling system to see what else could be streamlined with this process.

 

[svsisu]

Some cool stuff happening! I recently learned how affordable metal 3D printing has become, so decided to explore some options for making coolant adapters and fittings. My radiator has 1.5" inlet/outlet ports, and the VW coolant pipes are basically 1.25", so I'll need some adapters. For the upper hose a sharp 90º down to go under the intercooler would be ideal, as well as incorporating a bleeder nipple near the top of the system to help pull any air out of the system into the coolant reservoir. I drew up a quick and dirty CAD model with the basic size and dimensions and got a quote to have the part printed in 316L stainless steel: $73.48 delivered to my doorstep. This opens up way more possibilities for oddly shaped hose adapters and manifolds, I am going to have to reevaluate my cooling system to see what else could be streamlined with this process.
View attachment 4165353

I don't know anything about metal 3D printing, but that seems crazy cheap. A 3" CT 26 turbo down pipe would be a great thing to CAD and have printed.

 

[AirheadNut]

I don't know anything about metal 3D printing, but that seems crazy cheap. A 3" CT 26 turbo down pipe would be a great thing to CAD and have printed.

Same, I was surprised how relatively inexpensive it was. Not that far off the price of some of VW's plastic hose connectors. Apparently the stainless prints have excellent weldability, too, so one could print a downpipe and weld on a v-band flange.