We continue this tale of Van-Related Hosiery with building out the intake and exhaust paths. At this point, I’ve statically tested the oil feed and return system (running the engine and making hehe snail sounds) but to actually go anywhere I have to make sure the charge air can get into the engine.

As usual, the choice was between make or buy. I was able to find inexpensive (ish) “intake hats” sized for common carburetor air cleaners. These would have fit, since the IDI also has a circular ~5 inch ring to seat the air filter.

The other choice was bespoke IDI-specific products such as the welded intake adapter from Classic Diesel. Either option meant I had to break out the single tube into a dual configuration using one of those fancy silicone tees/elbows. I mean, both seemed like perfectly viable paths forward.

That, my friends, is why I’m not buying one of those. Remember the whole point of this project is to be unreasonable. With most of a spool of Markforged Onyx left over, you probably see what’s coming.

Yup, here we go! Time to whip together a design for a dual-intake turbo hat for my 2 inch Slinkyhose. The upside of doing this is I could put the inlets anywhere I wanted, corresponding to the clearest path upward from under the floor.

The design isn’t complex. First I modeled a large dome that’s the size of the air intake adapter ring, then made two tangential cylinders outwards at the diameter I needed. I used a Shell operation to make a constant 5mm wall thickness, then made a revolution feature for the “bead” to capture the Slinkyhose.

More interesting was making a spot that will eventually house the pressure take-off points for wastegates and boost readouts. I wanted to make sure to model it in, since you can’t really drill a hole in it when done.

On top of that, I wanted it to not compromise the top surface (it’s not a perfect dome) and to span many layers at different angles for strength. The area would have multiple perimeters being laid down, and if I threaded it afterwards, the threads will grab many of those perimeters across layers.

So putting it at an angle, tangent to the dome, was the choice here. This required a bit of setup geometry, such as making a cross-section sketch to reference an extrusion plane from.

Once the plane was defined using the angled tangent line, then I could make the feature itself

The hole and its flat boss were made very large because I was originally intending to find an orientation where I could print this thing using it as the bottom, using no support lattices. If I really had it my way, it would allow the overhanging round beads at the inlets to be printed supportless as well.

The Markforged printers are basically the only printers I trust to pull these kinds of shenanigans off. A little bit of it I review in the Dumpster Miku post – it usually relies on trusting your printer to hang the whole part off one comparatively small surface, maybe with some support lattices at the very end to give you some reprieve.

Unfortunately with the inlets positioned the way they are, there was not a good solution to this. In retrospect, there is another geometric solution for the charge air hose in the engine bay that I didn’t see right away. So maybe a future revision will move these to a different angle of orientation.

I continued the extrusion inside as well to give the thru-hole area a little more meat. Remember, 15 PSI doesn’t sound like all that much, but there’s a lot of square inches pushing upwards and outwards here. At just over 19 square inches of circular area, that means about 300 pounds is going to be making the intake hat trying to explode off if I really go ham.

There was another slight modeling oopsie that I should have taken into account. Adding the circular beads would have made the uppermost point of the model not coincide with the flat circular face. Maybe I could have printed it open side down, but that was going to be a 70 hour print using almost as much material for support as the model.

So for now, I got rid of the beads. I’ll just… dunno, tighten the hose clamps more or something. That way, the entire thing can be printed “open side up”.

Print in progress! This was going to be about a day. If I were a crafty, well-equipped fabricator, I could probably bang out a welded aluminum intake hat in a few hours. But alas, I am not, and I also have other stuff to work on while this is finishing.

Finished without any issues!

There was a last-second feature I added which didn’t make it to the CAD screenshots. I added a ridge to the bottom-facing side to avoid printing severe overhang angles as it began the inlet circle profile. I figured I could just belt sand the ridges off afterwards, which is what’s shown above.

To make the 1/8″ NPT threads, I heated up a fitting with a heat gun to the point where I saw the plastic beginning to swell up. Then just cranked the fitting in all the way to heat-set the threads. This leaves a stronger hole than using a cutting tap to cut the threads into the plastic. The same concept is used in metals by using forming taps, which is common in soft metals like aluminum.

The heat-forming fitting was replaced by a haphazard Tee splitter made of a tee block and two right angle fittings. They sell the correct thing, I just had these on hand and burnouts now good ideas later, etc.

Test fit! A big fender washer holds the fort down from above using the OEM air cleaner bolt location. Remember: 300 something pounds.

If I wanted to be more legitimate, there would be a larger diameter thicker steel disc in place of that washer, backed up by stacked Bellevlle springs to achieve the level of tension I designed for.

> implies I designed any of this

Here’s what the slinkyhose fitup looks like! Notice that I’ve also adhered the intake hat to the manifold with plenty of orange silicone.

The left charge hose follows the auxiliary (rear) heater hoses downwards and meets the turbo compressor outlet very cleanly. Vantruck doesn’t have these aux heater hoses since it never had a rear section to begin with, so I’ll need to extend a small bracket out for the charge hose.

The right hose is a little weirder. It winds downwards using the valley between the heads and follows the transmission dipstick most of the way.

I then divert it away from the downpipe that feeds the right turbo. It looks really close from this perspective, but there’s about 1.5″ of minimum separation – good enough for now. The finished product will be heat-wrapped, too, for protection.

So that does it for the intake. As of this point, I could freely make hehe snail sounds to my heart’s content… and it really could be driveable, but I was sitting in a cloud of diesel smoke whenever it ran. That’s because I still need to route the exhaust path.

The Exhaust

Running the exhaust was to be a fairly simple exercise on the right side – the turbine outlet points straight backwards. The left side was going to be the problem here, because in my infinite wisdom I forgot the oil filter existed and therefore the left turbo had to (for now) exit forwards.

Hood stack? Maybe, but Vantruck isn’t going to have one of those, and I’d need to solve that geometry fitting issue later. For now, I needed to make a tight U-turn to get the left side exhaust to face backwards.

As I found out, most mandrel-bent exhaust pipe have a minimum bend diameter of about 3-4x diameter, so a 2.5″ pipe’s U-turn part would end up about 10+ inches across. This was too much to fit in the area I had between the engine mounting crossmember and the frame rail.

They do sell some really tight “turn stock” that seems to be made by hydroforming or stamping-then-welding or similar. I considered picking one of these up, and I will if Vantruck ends up having no other geometric solution.

But in the mean time, here is the content we all stay for:

Exhaust tips welded back to back. How’s THAT for “exhaust restriction”?!

One end gets cut off and the 2.5″ V-band flange is appended to it.

Ironically, this was actually just too tight, and I couldn’t get the flange to seat. Doing this at least let me see which way I can expand.

Alright, out comes the bandsaw again… I cut the weld apart and added a roughly 1.25″ wide chunk of 2.5″ exhaust pipe which I squished in the vise to emulate the oval cross section of the cut.

Don’t even start with me. I am above the law.

This setup does come a bit close to the radius arm bushing (on the very right), so I really want to make sure the final product can exfiltrate facing backwards. There’s a potential solution that involves rolling the turbo (with compressor inlet facing forward) around 45 degrees to clear the oil filter.

About this time, I got a Snail Snuggie in the mail. These kits come with a woven something or other (claimed to be fiberglass or other mineral cloth), some stainless steel ties and springs, and a big roll of exhaust pipe wrap. I’m not going to install this for now, but it’s a good look ahead. I do want Vantruck’s turbos wrapped up to avoid sudden heat shock like from standing water hitting a very hot turbine housing.

I didn’t want the turbos to be purely hanging off the relatively skinny-walled downpipes, but I also can’t rigid-mount them either. At least, not this driver’s side one. I cut a universal rubber hanger to the right length such that the clamps pull up on the pipe just a little. Enough to relieve the weight of the pipe section after it.

The right turbo could be rigid mounted to the transmission, it turns out. The transmission has a mounting ear or service stand hole that I could hang a quick bracket off.

Perhaps if I can find the other geometric solution for the left one, it can be supported by the transmission as well. There’s another one of these tabs on the forward left side.

This bracket was made from a section of 1 inch square steel tubing with two skew-drilled holes.

I think this mount will make it into “final production”. The job of this mount is also to relieve the weight of the turbo more than anything. Behind the respective mounting points, I’m going to use a segment of that flexible coil pipe before any other segments.

However, I didn’t have any on hand. At least not in 2.5 inch diameter. And so, with everything ELSE already hooked up and statically run a few times…

Oh, why the hell not. With the exhaust path at least vaguely pointing backwards, it was time to go to Autozone to buy your own parts!

Keep in mind the state of things right now: No increased fuel, wastegates left as they came (8 PSI – unverified), charge air hooked up, no exhaust path. It’s still just a van that makes hehe snail sounds. I strapped a camera to a tripod and recorded this POV drive first.

I did it with the interior doghouse off in order to keep the slinkyhose in my field of view. I could see the little segments inflating or stiffening up ever so slightly, but the fiberglass winding keeps it all in place. The Slinkyhose did not fly off the intake adapter, but that’s going to happen eventually as I step things up. The smoke filling the cabin was due to unfavorable winds pushing the exhaust right back in my face.

This was not a pleasant test drive.

Whatever, it works! Time to make it work in a little more civilized (just barely more) fashion. Using the Autozone’d exhaust parts, I cooked up some low production value Lake Pipes. On the left, a segment of slinky-pipe (as opposed to slinky-hose…. so many slinkies in this whole build!) makes the frame jump immediately aft of the radius arm bushings, from the U-turn.

On the right, just a short extension to bring the two exhausts roughly to the same distance along the frame.

Then a set of somewhat-matching 90 degree turns. On the right side, I do the flex-pipe frame jump after the extension; on the left, it’s already outside, so it’s rigid pipe all the way back. This was all just beat in with exhaust clamps.

I’ve gotten Snekvan to a stage where I could actually drive it places, so I did just to shake everything a few times. With the oil feed/return system, intake hosiery, and exhaust all seemingly solid (with completely OEM fueling levels), it was time to put some instruments on it. I ordered some cheap boost gauges and EGT probes from Amazon.

Without this information, I don’t know when it’ll explode, but with it, I’d be satisfied with bringing it to the very edge of explosion or slightly past it. Look, if it explodes, I’d at least want to know why… so the next try can back down just a little bit.

So one of the final big integration jobs to finish before I can go take Snekvan on a joyride is the oil return system coming from the two turbos. This is a more complex system than the usual setup of one turbo mounted up high near the exhaust manifold, because these both sit well below the engine oil sump level. They therefore can’t just gravity drain with a simple tube or riser/pedestal.

Instead, I picked up a small self-priming solenoid pump and will have it sucking on the oil drain ports of the turbos, returning the oil up to the engine somewhere. Before I get there, though, I had to route the oil lines themselves.

In that “So What Now!?” post you can see some of the parts I sampled off the finest discarded leftovers from eBay Motorsports™ such as oil fittings and whatnot. I found that #4 AN fittings were the most common plug n’ play system for oil feed lines, and so I ordered a few different lengths of pre-made braided lines.

The jumping off point for oil pressure is this cross-drilled gallery plug on the lower left (driver’s) side of the engine, right in front of the transmission adapter plate. Now, Nick Pisca is a little critical of the Banks style turbo kits which use this location for the oil feed, but I think in my application having the feed line as low as possible will minimize the amount of oil that has to be gravitationally drained after shutdown.

Notice here that i used a three-way tee fitting, a 1/8″-NPT male to two #4AN. In retrospect, now that all this is over, I should have routed the right-hand side turbo’s oil feed not up and over the transmission (as it creates a long path that has to be cleared by the bilge pump after shutdown). However, in November of last year, I didn’t know this yet. Up and over the transmission instead of tucking this line under the bell housing made more sense.

I formulated what hoses and fittings I needed for the return lines and ordered them from Amazon, the universal provider of almost any strange tube/hose fitting you can imagine.

Here’s the gist of the setup for doing the oil return. From right side to left side:

• The #10 AN right-angle swivel couplers with 3/8″ barb fittings will attach to the outlet fitting on the turbo center cartridge
• The lines will join at the tee joint made of 3/8″ barb fittings
• They’ll go to the inlet of the Facet clickypump
• The outlet of the Facet clicky pump is a long hose that goes up and over the engine and into the timing gear screw cover on the front.
• A modified bulkhead barb fitting will be drilled and mounted into said timing gear screw cover.

I had to generate a Bracketry to mount the Facet bilge pump so the rest of the hose lengths could be determined. This was to mount by the transmission at one of several convenient bolt hole locations offered by the shift linkage mounting bracket.

Probably the nicest Bracketry I’ve ever made by hand, honestly. It juuuuuuuuuuuuuuuuuuust about looks manufactured. I finished all the edges with a bit of belt sanding and then used a hand orbital sander to stir up the flat faces, giving them a bit of a abrasive-tumbled finish. All for nothing, of course, as this thing will just sit below everything else getting shat on by weather and van droppings.

This is the mounting location. Awfully close to the shift linkage, right!? This is shown in the farthest travel (1st manual gear). Remember, every part of a Ford Econoline is located no more than 1/4″ away from every other part. Literally my design guideline for making the Bracketry.

Experienced low-mount/remote mount turbo installers will instantly see the problem with my setup here. I mean, beyond the Teflon hose I bought. I really began hating this hose – what’s called “Flexible” in industrial land is probably not very flexible at all in the common sense. It might be flexible enough to bend around inside a giant machine.

The unreinforced Teflon hose also kinked and crimped if I looked at it. You can see that I’m trying to use a heat gun to soften it so I could actually make it turn and align with the fittings. This ended up being kind of a wash, and I decided that crinkled tubing was still fine for carrying fluids.

Up front, I’ve removed the timing gear screw cover and will drill a large hole in it for attaching the panel-mount hose barb fitting, which…

…has to have one side cut off and shaved down so it won’t hit the bolts spinning next to it.

The hex part was trimmed down to 3mm thick and then countersunk just a little – first to take the edge off, then I accidentally went too deep with the countersink and decided that maybe the oil could use a little more space.

The return fitting installed onto the timing gear screw cover.

Here’s what it looks like sticking out once installed.

The terrible Teflon hose just didn’t want to make the bend at all. Well, it is what it is.

A final step before firing everything up was to run power to the bilge pump. I grounded the pump locally on the Bracketry for the time being.

Power to the bilge pump was derived from the fuel filter heater element, which is commonly bypassed or deleted by modders. In Vantruck’s integration, similar to Spool Bus, this filter head will not be present at all. This heater is constantly on if the vehicle key switch is in the Run position, so it’s fine to use as the power source.

Except… well, Snekvan’s ignition switch was long broken off inside. So I just wired it to a random on/off switch instead.

Here’s a better look at the routing of that oil return hose, also showing the CDR Turnaround Bracket. Nothing’s hooked up otherwise at all: no exhaust path, no intake/charge hose, and no CDR hose. This first light-off is just going to test the viability of the oil feed and return.

And what a massive cloud of shame it made. Again, if you’ve installled remote/low mount turbos, you know exactly what happened.

The translucent Teflon hose was at least useful to confirm that, under steady-state operation, the oil was indeed flowing and being expelled by the bilge pump and returned to the top side of the engine. But I had to get rid of it right away. Besides just failing at everything and requiring a heat gun to form and get over the fitting barbs, it simply began cracking around those fittings too.

The revision used fuel hose and a more compact routing, including a relocation of the bilge pump. Why?

Well, it’s that “If you’ve done this before, you probably see what I fucked up” allusion: The initial pump placement was higher than the turbo bearings. As a result, when I shut everything off, a static head of oil above the bearing level was still present. This slowly seeped out of the bearings and into the exhaust turbine, making the massive clouds of white oil vape whenever it next ran.

The fix is placing the bilge pump lower than the turbo bearings, ideally the lowest possible point. There’s not much lower I can really go, so I might investigate later on using two of these small clickypumps together – besides for redundancy matters, it would allow me to have a much shorter flow path between the return fittings and the pump.

I also gave some thought here into figuring out a lower profile drain fitting. The #10 AN flange mount and right angle adapter were convenient, but added like 2+ inches of drop to the oil drain. I want to run a smaller tube fitting size here so the clickypump has more suction leverage on the oil in general.

But that’s for another day. At this point, I had a van with two whistles attached to it. I still needed to figure out a charge air routing solution and exhaust solution.