Waterpumper/Swap Guys - Heater Core up Front

[Vee Dub Nut]

For all you swapped water pumper guys, got a question about heat. There has been some chatter in my Buses build thread about various heating options, and I thought I'd throw this question out in its own thread for a broader exposure and input.  

-Are any of you guys running heater cores all the way up front in your Bus? If so, are they mounted at floor level, or elevated behind the dash? 

-Any issues with flow from the water pump pushing coolant all the way up there and back (particularly Subaru guys)?

My original plans for heat were targeted around running a rear mounted under seat heater core, which keeps the core relatively close to the engine and limits how much hose length/etc the engine has to circulate its coolant through. BUT, I have also been planning all along on running AC in the future, and I also want to make the defrost work in some capacity so that the Bus is truly usable in a variety of weather conditions. Pretty quickly this turns into having three separate systems for each function (heat, ac, and defrost), and this gets sort of clunky. I don't really want three sets of fans/controls to manage all three functions.

Soooooo... to maybe implement a more polished solution, I've also been toying with the idea of building in a full modern type HVAC unit behind the dash that incorporates the AC evaporator, heater core, and dampers for defrost all from a single unit. These universal hvac assemblies can be purchased from a few different sources, and would obviously require a fair amount of fabrication to make work. My primary concern however, is that the heater core would be on the complete other end of the Bus and elevated above the engine a good ways being tucked up under the dash. I understand I would have to bleed air from from the heater core when filling the system which is not a big issue, but I'm a bit concerned about having too much head loss and not getting good coolant flow through the core/heater loop. This would obviously limit how well the heater would work.  

Anyone have any first hand/practical experience with this? Am I over thinking this?

Also, for those that don't know, the Subaru heater core loop was originally designed in a way that it MUST flow coolant all the time to get proper thermostat operation. If you block off the heater core lines, or overcool the heater core flow loop, the engine will not properly regulate temp and can actually overheat in cold weather. There are some modifications that can be done to the cooling system to overcome this. I think for a rear mounted heater core its likely not really needed, but for a front mounted core, probably a good idea. Not really worried about this aspect at all, and am more wanting to discuss any potential flow and heat issues with the core being so far from the engine.
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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

[skills@eurocarsplus]

camp out in the vanagon forms a bit. the Subaru pump is just fine in a vanagon, and they are pushing a hell of a lot more coolant than we could ever throw at a bay.

there are 2 style Subaru pumps (well, more if you add WRX etc) but the 2111 AA 007 is the "riverboat" style, closed impeller and the 21111 AA 110 is the "pinwheel" or open impeller style.

honestly, I think it's 6 of 1, 1/2 dozen of the other. the closed style reportedly flows more. until I see real GPM, i'm not convinced
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[KrisBalfe]

This is what I used. Happy with it.
Vintage air

[alaskadan]

Ive done 2 bay/suby conversions and both got Maradyne brand marine heaters. One under the rear bench and one under the front floor with a custom plenum connected to the original duct work. The advantage of KrisBalfe's one in the glove box is it recirculates the warm air vs the ones I installed under the front draw in fresh air only. Never noticed much issue with a rainy day pumping steam in per se. As well these 2 vans get parked when it gets really cold.

[Vee Dub Nut]

[Vee Dub Nut]

[Vee Dub Nut]

[tristessa]

I've got the 26000btu/200cfm Maradyne up front in my '75. Originally it was just below the dash on the glovebox side, and I had to add an expansion bottle up there because the cooling system wouldn't bleed properly.

I moved it to under the floor just ahead of the parking brake mechanism and ducted it into the stock "tree" from there last year fallin preparation for an A/C evaporator in the under-glovebox location. Heat output with it drawing fresh air from above the belly pan seems about the same as before when it was recirculating...

[skills@eurocarsplus]

[KrisBalfe]

[/quote]

Thanks for chiming in. This is the EXACT unit I've been looking at too. Glad to see that it fits like I thought it would.

No issues with the heater core being so far away?[/quote]

I may have had to modify a few things to get it to sit in there like that, I will see if I have pictures. It is set up like a vanagon essentially so no problems.

[tristessa]

[notchboy]

[Abscate]

Deserts are the Creators way of saying, scorpions live here, the rest of you live somewhere else.
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.ssS!

[Vee Dub Nut]

[Vee Dub Nut]

[vwwestyman]

I don't think I have any pics of the Vanagon heater core setup I currently have there, but here is the marine heater I originally had in the front. It didn't put out as much heat as the Vanagon rear heater, so that's why I swapped it.

But the setup is essentially the same.

Like I said in another thread, I plan to eventually flip it and mount to the underside of the floor so I can remove the splash pan without dropping the heater.

I have considered getting a bigger heater and mounting it, which would require cutting a part of the splash pan and re-boxing it in to contain/protect the heater. Who knows if/when I'll ever get to that.

I have also drilled out the screw holes and installed nut-serts to mount the pan a bit more securely.
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Dave Cook

President, Wild Westerner Club

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

[vwwestyman]

From your other thread, for the benefit of this one:

[notchboy]

So if I was able to run my stock heat and my eberspacher and obtain a nice low 80's temp inside with outside temps around or slightly below freezing in Seattle. Id think that these set ups should be well above adequate for heating your bus.

I thinks Skills already said his rear heat was sufficient. I like this up front type you have Dave and would for sure want something like this if I ran a WC motor. I mean why not have a dedicated windshield/front occupant heating source as you'd want to use it 90% of the time to heat yourself.
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[tristessa]

Well, yeah. The Airtronic clone I've got installed is really more for heat when I'm camping .. though being able to preheat the interior by pushing a button on the remote while I'm sitting in the house finishing coffee is nice. =D

[vwwestyman]

Because the thread title is "up front" I didn't mention I also have rear heat!

I, more or less, attempted to copy and Busify the Vanagon heating system with my TDI bus.

As Tristessa said, the Espar heater is best used as a camping heater and as auxillary heating in combination with the heater core(s).
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Dave Cook

President, Wild Westerner Club

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