Vee Dub Nut's 74 Bay Transporter (& Subaru EJ25 Swap)

[skills@eurocarsplus]

[Vee Dub Nut]

[vwwestyman]

For my Bus' heat, I currently have two Vanagon rear heater core setups. One is under the back seat, and one is attached to the splash pan up front, blowing into the heater "tree." At some point, I may flip it so it's mounted to the underside of the floor rather than the splash pan.

To control the temp/cut off the heat completely, I put an inline heater valve in the feed hose. It is at the back, close to where one of the heat exchanger cables exits it's tube. I modified the end of that cable to work with the valve. I also used an assist spring to pull it into the closed position. Now I can turn the heat on or off via the lever on the dash! I don't remember what exact valve I used; I just picked it out of the catalog at the FLAPS based on inlet/outlet size and how the open/closed arm was arranged.

I'm pretty sure there is info on this in my TDI build thread. I think I did all that in the summer of 2016.

You'll want to make sure that this setup will work with the thermostat's requirements if you go that route.

I haven't had any issues with bleeding either core with this setup.

I have gone to using a vacuum bleeder-you draw a vacuum in the system, then put a hose in your jug of coolant and open a valve, and the coolant is drawn into the system. Works really well! There have been times I've opened the air bleeders on the heaters and times I haven't and it seems that all the air gets pushed out of them just fine pretty quickly. My SOP is vacuum, fill the system, vacuum one more time to just make sure, draw in a little more coolant, top it off, drive, top off again, done.
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[Vee Dub Nut]

Thanks for the input Dave!

I've got several different options/directions I'm now considering. Hoping to narrow it down and start ordering some pieces. Don't need to have the AC side figured out any time soon, but certainly need to get going on heat (and defrost).

And noted regarding the thermostat compatibility part. I'm probably going to get Tom Sheils thermostat housing spacer do-dad which moves the t-stat down lower out of the return flow from the heater, and adds a small return line from the Subaru cross over to provide heated flow directly to the t-stat for control. Seems like a good way to crack that nut.
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Fightin' Texas Aggie Class of 2006

67 Beetle (TBD)

74 Transporter (EJ25 Swapped) - Build Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

See all my VW pics on Instagram @ vee_dub_nut

[Vee Dub Nut]

Time for another update...

Finally made some decisions about how to handle heat in the Bus. I explored the combined heat/evap/defrost units pretty extensively, but ultimately opted to go with a separate heat unit. The primary issue was, when I found a combined unit that actually stated it had a decent enough capacity to take on the interior volume size of the Bus, the unit was WAY to big to get behind the dash. Well, get behind the dash without essentially redoing/removing everything behind the dash from about mid way all the way over to the passenger side (i.e. radio, existing ducting, e-brake assembly, etc). It was just going to snowball into more modification/non stock custom stuff than I wanted, so instead I opted to separate the heat and air functions and picked a more traditional marine style heater used by a lot of other swappers (AC will come later using an OG underdash evaporator setup I have).

As for my heat I picked up a 40k BTU marine heater labeled by Summit. Its a Summit rebranded deal, and has a Maradyne sticker right on it. It is a complete heater core and enclosure, with 3ea 3" outlets and a 3 speed fan. To hook it up I grabbed a 20' box of 5/8 silicon heater hose from Vibrant Performance, and a cable operated bypassing heater control valve from Old Air Products.

Looking at mounting location for the heater itself, with the physical size of the larger 40k BTU heater compared to the smaller 2 outlet unit, mounting it up front under the front floor in the belly pan area was not possible. So for interior mounting my two real options were under the rear seat, or the middle one (didn't want it under the dash). A lot of folks go with under the rear seat mounting and I can certainly see why, but after considering the two options, I opted to go with putting it under the middle seat. My Bus being a transporter and used primarily for hauling the family around, I have the middle seat installed ALL THE TIME. It hasn't been removed from the Bus since I installed it 2 years ago. Secondly, the area under my rear seat is already crowded with the swap stuff. I could condense that down and make room, but I like the way its all laid out right now, everything can be easily gotten to without having to remove the seat. Thirdly, I hope that by putting the heater under the middle seat, right in the mid section of the Bus, that I will get the best chance at evenly heating the interior. That's my justification anyways, ymmv.

Here are a few pics of my mocking up the location. Reminds me of those old school Bus heaters under the seat in the back of the Bus as a kid I'm going to make a trim/kick panel for the seat stand legs like it had originally, which will essentially keep all of the heater out of sight when the slider door is opened.

Happy with that location, I went ahead and removed all the middle seat, belts, and floor mat to start working on mounting. The heater itself comes with some pretty decent brackets for mounting. Instead of using the supplied sheet metal screws however, I opted to use nut-serts in the floor instead and bolt it down with a small M6 bolt.

For getting the heater core lines up to it, I had originally hoped to use the large OG center duct hole to route the lines up, but unfortunately its just plain in the wrong spot to be useful. Oh well, instead I picked up some grommets, and popped a couple of holes in the floor for the lines to pass through. Easily patchable in the future if I desire, and the most compact/simple way to get the lines through the floor (I had also looked at some bulkheads for the lines, but they added a lot of complexity, weight, and potential leak points). Upwards and onwards, like a hot knife through butter!

That pretty well brings us up to current time. Been braving the cold shop each night making small progress each day. Hope to have it wrapped up this weekend. I'll post more as I continue.
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Fightin' Texas Aggie Class of 2006

67 Beetle (TBD)

74 Transporter (EJ25 Swapped) - Build Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

See all my VW pics on Instagram @ vee_dub_nut

[Vee Dub Nut]

Now for a non hvac update, I also recently splurged on a new shifter I've been lusting after. Sure its completely impractical and unnecessary, but I've been wanting one for a while, so I finally bit the bullet. Hey, lets be honest, this whole Bus isn't exactly practical

What I picked up was the Bug-Tech Bus shifter out of the UK. Its all CNC machined aluminum and hand assembled. Its VERY well built. Overall it has a nice substantial feel in the hand and through shifts, and of course shortens the throw quite a bit. Took a bit of time between order and delivery being built to order, but I finally got it and I love it. Obviously a pretty straight forward install (it's just a shifter).

A few pics. Yes you have to cut the mat for the large base, but no deal breaker for me.

Certainly not a modification/part that is for everyone, but if you've been interested in one, I'd recommend it. Its a real nice piece, and sort of icing on top of the cake for how well the Bus has come together
_________________
Fightin' Texas Aggie Class of 2006

67 Beetle (TBD)

74 Transporter (EJ25 Swapped) - Build Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

See all my VW pics on Instagram @ vee_dub_nut

[skills@eurocarsplus]

it's a long story, and when I have time i'll add more....

I put a front heater in dumpy bus a week or 2 ago. long story short is the juice wasn't worth the squeeze. best could muster is about 120* at the dash. the super long run(s) cooled the coolant down too much.

rear (under seat) heater was still toasty hot. I have come to the conclusion without some serious $$ spent, heating these to todays standards is going to be an expensive challenge

I was so disappointed, I bought one of those chinka china diesel heaters. 220* at the dash vent.

I loosely mounted it (ahem, zip ties) just behind the beam and used the factory duct + routing. the challenge with those is the exhaust...they can't be too long...but vw stuck their belly heater exhaust by the l/r 1/4 window....so i'm torn about how to make good heat up front using the defrost.

I an going to assume the billion dollar vintage air would have performed poorly as well...my inlet coolant temp was 150* on a warmed up (185-90*) engine. it's just too long of a run...
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[danfromsyr]

how would a that differ than how a vanagon has the long run to the dash.
plenty of them have plenty of heat, with front & rear heaters.

in my 1980 with a 1.8t swap. so we know it's not the same.. but I can't hold my hand over the dash vents while traveling for more than 20seconds.. and I'm no temp lightweight.

the thermostat controls and maintains a system temperature. with what coolant it has control over.either you have too cool of a T-stat or you are allowing too much return flow uncontrolled (by the t-stat) from the radiator.

iirc and in my opinion your systems run cool. which is fine in summer. but these aren't really frigid temps.. even in the teens. should be plenty of heat..
might want to look at the cooling flow diagram closer something isn't right.

put pipe insulation on the heater core supply line.. then there will be negligible heat loss.

the heat forced chinese heater isn't a bad option in a large bus either.. even gasoline H2o vanagons had them as options. though the Eberspacher option was $$$$ and less popular towards the end.

edit: I agree I don't wish to muddy his thread either, I just don't think it's insurmountable. even if you don't wish to continue it.. love what ya do for these guys.

[skills@eurocarsplus]

i'm not going to muddy his thread....

I put a feedback loop like the Subaru needs. it for sure stabilized cold weather temps...a solid 185-190. stock (dealer) t stat.

I can trace the heater output line to the point it just cools down...

pinching off the rear core helped...but not much. burn your hand at the rear core...front is like a warm beer fart. best temp at front ducts was about 150*

it is what it is....I just don't have time to sort a better solution...99% of my clients park them as soon as the salt truck is out.

my cooling system is huge...3.5 gallons (from dead empty) probably closer to 4 with a front core. that is a LOT of coolant to warm up.

in the end, it does seem to help 'equalize' the bus in terms of heat...meaning it's a bit more even if you will, but the rear core is like I tell people...it's like central air in your house...not hot in any one area, just comfortable.

don't get me wrong, the rear heat only works well for most. dumpy buses owners were happy...but I wanted better.

until I see someone with a swap and 190* out of the dash...I call this "myth busted" I did not insulate the hoses...that may have helped a tiny bit.
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[Abscate]

[vwwestyman]

I don't know how Skills tried the front heater, but I'm pretty sure that the Vanagon rear heater I'm using in the front of my Bus is smaller than a Vanagon front heater. I'm sure that is a good chunk of the difference you're reporting.

I have insulated my pipes which I think does help at least a little.

I've considered adding a pump to pull water through the cores, but haven't done it. If I would, I'd have it be triggered by the switch under the heater lever.

I also noticed this week I need to swap the thermostat; it is apparently keeping the engine too cool... Saw temps around 165-170 this week tops. No bueno in the winter!
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Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[Vee Dub Nut]

Interesting info Skills, thanks for sharing! No worries about muddying up the thread, it's all good info.

I do think it's probably possible to get a combined ac/heat/defrost unit to work, but I'd bet you'd essentially have to gut most of the stuff behind the dash and redo everything one-off. For me, the juice just isn't worth the squeeze. I'm trying to leave most everything EXCEPT the powertrain stock bay Bus. Same reason I haven't done any crazy gauge cluster swap, or some giant double DIN radio, etc (although I do like the skillz subi gauge setup).

Anyways, back to my project. Been continuing to plug away at the heater install. Last night I got all the plumbing completed, and tonight I wrapped up re-installing/re-routing some electrical stuff I had over on the right hand side of the trans where the heater control valve now resides. That's really my only real complaint, is that the right side of the trans is getting busy. I have the starter, stock Bus wiring, fuel pump, pre-filter, main subi-wiring power feed/breaker, coolant suction line, and now heater core lines all in that spot. Its getting tight. Still reasonably OK to work on, but you'd certainly have to work around stuff. Thing is, that's just the natural spot for all those things given the subi engine and stock bus layout. Cest la vie...

Here are a few shots of the heater core fully plumbed from the top side

Coolant lines themselves routed well. I don't intend to insulate them at this point. Hopefully that doesn't come back to bite me. (PS, I'm a zip tie master )

Here is the heater control valve I've been referring to. It's a bypassing type valve, meaning when its closed it's "bypassing" the heater core with coolant just returning straight back to the engine (i.e. it flows coolant all the time). However as the valve is opened, coolant will then be diverted up through the core before making its way back to the engine. Its a mixing type valve, meaning I can vary heater core fluid flow from 0 to 100% of the valve. This combined with fan speed on the blower should give me pretty decent control over volume and temperature of the heater air discharge. I picked the valve up from Old Air Products. Its actually just a GM vacuum operated valve with the vacuum pot removed, and this cable bracket attached. Should be on par with OEM level quality parts.

As for the cable, I just nipped off the last ~12" or so of the heater control tube on that side, and then clamped the factory inner cable to the bracket on the valve. Pretty quick fit up overall. With the stock pull on the cable, I'm only getting about 75% of the valve action. I'll need to tweak the cable attachment to pivot point on either the valve end or the lever under the dash to get a touch more stroke out of it. For now I just split the difference and moved on. Here is a quick video of the valve in action.


Link

That brings us back up to current time. All I have left is to wire up the fan on the heater, pop the radiator back in and fill with coolant, and get the rear mat and seat reinstalled. Hopefully I can knock that stuff out tomorrow and be back back in business.
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Fightin' Texas Aggie Class of 2006

67 Beetle (TBD)

74 Transporter (EJ25 Swapped) - Build Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

See all my VW pics on Instagram @ vee_dub_nut

[vwwestyman]

That valve looks like a pretty smooth operator.

I found mine worked much better with a helper spring pulling it back toward the closed position.
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[skills@eurocarsplus]

i'm interested to see what that heater puts out. I think the run to the front is won't work well, not the VA setup itself.

by the time I pushed 180* coolant to the front of the bus, it was about 150* at the front core's inlet. rear core was about operating temp.

that said ...to danfronsyr….the vanagon guys have an issue with the front heater core design...new ones are in/out without a baffle...so big difference to the maradyne's we run...which I assume are in/out for all intents and purposes.

I feel there is too much heat loss running to the front of the bus...by the time you run the 12' of hose to the front, that leaves a lot of surface to dissipate the heat...in a 'questionable' core.

like I said...it worked...just not epic heat like the rear core. it for sure evened out the heat if you will.

and again, most of my work gets parked come winter but I would like a better solution to a front heater. again, insulating the lines may help a bit, i'm not sure
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[Vee Dub Nut]

[Vee Dub Nut]

[skills@eurocarsplus]

i'm sure you know...

the 9" heaters don't have a bias, but the bigger ones (like yours) do have an inlet/outlet on the core. be sure to hook it up right.

your runs are longer than a under seat unit for sure, but not by too much. i'm willing to bet you'll be happy with the heat output of that unit
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[Vee Dub Nut]

[Vee Dub Nut]

Did get my install wrapped up this weekend. Took longer than I had expected, but that always seems to be the case with anything in the shop. Every time I get into a project like this, it seems 3 or 4 other little small projects crop up. Its always a "while I'm in here" sort of thing.

I did add a little insulation to my heater core lines before reinstalling the radiator. Will it make any difference? Who knows... But I figure it was only a couple of bucks to do, so it seemed like a no brainer. I only added it on the section of lines over the top of the radiator itself, as I figured I am purposely trying to get air flowing through that area to feed the radiator, so I should at least try and shield that portion of the heater core lines.

Didn't get any real pics of the wiring, but I ran an 8awg feed through a 30amp circuit breaker from the battery to a small fuse panel mounted under the dash. My intentions were to go ahead and run this now, as I will use it later when I go to power up all the under dash AC stuff next year. I mounted the heaters blower switch to the right of the emergency flasher using one of the factory holes in the dash. It fit up pretty nice, and is easy to reach.

With the install "done", I went about getting the interior all back in it. Had to trim the cargo mat under the seat, but it all fits well. Here you can see how well it tucks up under the seat.

And for the pièce de résistance... my newly crafted kick panel that hides everything from sight though the open slider. Can't beat that!

Pretty happy with how that all came together.

After I was done I popped the coolant back in, cracked the bleeders to vent any trapped air, and then fired it up. I always like to leave the system open (i.e. the coolant ball) and get one full heat cycle on the engine to let the t-stat open before I top off the reservoir and cap it all back up. After getting it up to temp I was able to do some tests with the heater. The blower itself is audible, but not terribly loud or annoying. Heater output seems pretty good, at least it feels nice and warm. Oddly, the center duct feels a little hotter than the two outer ones. Not sure why that is.

To try and put some "science" to it, I did some google searching to see what sort of temps it should be putting out. It seems that "normal" acceptable outlet temps at the duct with full heat is 115-120F, with some systems hitting 135-155F. Saw those temperatures referenced on a few pages (including popular mechanics). Right? Wrong? Dunno... I did some measurements on mine just to see, but it's hard to really boil the output down to a single temp, as it is HIGHLY dependent on a lot of factors. From my measurements I saw temps anywhere from ~110-145 just playing around with it in the shop. In general:

**Outlet temp with the fan on low speed is higher than the temp with the fan on high. Makes sense I guess, as coolant flow remains constant, putting more air across the core will reduce the dT of the air

**Outlet temp on all speed settings comes up pretty significantly (~15-20%) with increasing the engine speed off idle. Also makes sense, as this should have a pretty large impact in coolant flow through the core

**Outlet temp of the heater tends to drop off some after the engine is fully warmed and the tstat opens up. My assumption is that you essentially loose some flow through the heater core, as the water pump output now has two paths to flow through, and presumably flow through the radiator shouldn't provide a lot of resistance.

So are my temps lower than it should be??... dunno. Skills seemed to suggest higher temps from some of his work. I'm curious to measure mine further under more "real world" conditions than just sitting idling in the shop. This would probably give me a better idea of what its really capable of. I do think that the current linkage for the heater valve isn't opening it quite all the way, although I did bias it more towards to open end of the valve than the closed end. I also don't know if that valve might be a bit of a restriction too. Not sure what short of cv it actually might have.

Regardless of all that, driving it around today it seems to put out more than enough heat. The control valve is nice too, as I can trim back the coolant flow and knock some heat out of the output. This will help keep us from cooking after knocking the cold out of the Bus. Time will tell I guess...
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Fightin' Texas Aggie Class of 2006

67 Beetle (TBD)

74 Transporter (EJ25 Swapped) - Build Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

See all my VW pics on Instagram @ vee_dub_nut

[panel]

What's next for this thing.......power windows . I love this thing and your updates!
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My '65-Subaru EJ20 Turbo conversion