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914World.com _ 914World Garage _ Best way to add heat to a Subaru conversion?
Posted by: CptTripps Dec 16 2013, 08:30 PM
I would like to add heat and defrost to my Subaru conversion, but I'm not sure the best way to do it. Now, I'm no expert on the ventalation system of these cars, but I was hoping to have something simple like 2 discrete motors. One for the vents on the dash, and another for the defrost.
The stock heat blowers are intact on the car, but I don't believe they're hooked up at all, since the PO had a SB350 installed. That motor is going bye-bye, and I'm not sure the best way to add something to replace it. I don't need fire shooting out of the vents like my Land Rover, just enough to get the windscreen clear and take the edge off of a cool night.
I see a few aftermarket blowers that I can put in-line with the heat tubes, but how should I GET the heat? Is thee a way to do it from the water in the radiator?
Posted by: bfrymire Dec 16 2013, 08:47 PM
I would like to add heat and defrost to my Subaru conversion, but I'm not sure the best way to do it. Now, I'm no expert on the ventalation system of these cars, but I was hoping to have something simple like 2 discrete motors. One for the vents on the dash, and another for the defrost.
The stock heat blowers are intact on the car, but I don't believe they're hooked up at all, since the PO had a SB350 installed. That motor is going bye-bye, and I'm not sure the best way to add something to replace it. I don't need fire shooting out of the vents like my Land Rover, just enough to get the windscreen clear and take the edge off of a cool night.
I see a few aftermarket blowers that I can put in-line with the heat tubes, but how should I GET the heat? Is thee a way to do it from the water in the radiator?
How about a hot rod heater? Speedway motors has one...
--brett
Posted by: bulitt Dec 16 2013, 08:59 PM
Do a search under Marks914. He put an oil cooler in the fan blower box and ran coolant through it via a valve.
Posted by: McMark Dec 16 2013, 09:30 PM
I'd look at a motorcycle oil cooler, mounted in front of the tubes in the engine bay and plumbed in the water system. Fabricate a shroud to connect the cooler to the round pipe and put a fan on it. One on each side probably. Wouldn't need a valve in them, IMHO. Just control the fans. And use the stock diverter valves to control direction.
Posted by: Mike Bellis Dec 16 2013, 09:34 PM
I did an oil cooler in the fresh air box. I did a how to here somewhere. I use the stock fav and control the water valve with the dash controls.
Posted by: Tilly74 Dec 16 2013, 10:06 PM
For my subie swap I plan to modify my fresh air box and install an a/c evaporator and ...haven't worked out the details yet, but I think my next step is a long day of digging through small vehicle dashboards at a pick-n-pull. The ultimate goal would be functioning heat and a/c through the fresh air box controls. For heat I want to use something like http://http://m.ebay.com/itm/331082538313?nav=SEARCH&sbk=1 and direct the heated air into the fresh air box where the factory heat came in from heat exchangers.
Posted by: BIGKAT_83 Dec 16 2013, 10:22 PM
Like mine here. Both heat and AC.
Still have to finsh this before next summer
Bob
Posted by: Mike Bellis Dec 16 2013, 10:23 PM
Here's my heater thread...
http://www.914world.com/bbs2/index.php?showtopic=105071&hl=watercooled+guys+bellis
Here's marks914...
http://www.914world.com/bbs2/index.php?showtopic=70317&hl=
Posted by: gryphon68 Dec 17 2013, 08:03 AM
Considering this myself.
This is where I'm leaning. Please feel free to shoot holes in my theory.
Using a expansion tank with radiator cap as the highest point in my coolant system. With the addition of a couple more inlets and outlets or some fitting tee's you can have a small electric pump circulate water through the heater core branch and return it to the tank.
Heater core and heater core branch lines need to be kept lower than the top of this tank.
Ideally this would probably be mounted on the rear wall of the front trunk.
You could either run one leg of the engine-to-radiator coolant lines through the tank, or what would probably be cleaner would be a large tee in one of the engine-to-radiator coolant lines running to the expansion tank.
Posted by: DBCooper Dec 17 2013, 08:22 AM
Wow, Bob, EXTREMELY sanitary! And you actually carry that broom around? Wow, that's above and beyond. 
Seriously, that's excellent, are there parts details in one of your threads?
Posted by: mepstein Dec 17 2013, 08:57 AM
Like mine here. Both heat and AC.
Still have to finsh this before next summer
BobExactly what I want to do when I build my subie conversion. factory appearance. Looks awesome!
Posted by: nsyr Dec 17 2013, 12:41 PM
Like mine here. Both heat and AC.
Still have to finsh this before next summer
BobWhat are you using in there??????
Posted by: CptTripps Dec 17 2013, 01:35 PM
Yeah, I'm waiting for that explanation too! That looks like a hot setup.
Posted by: Chris H. Dec 17 2013, 01:48 PM
Is this what you used Bob?
Posted by: mikesmith Dec 17 2013, 01:54 PM
The unit you linked is one of the Vintage Air under-dash units; very different from the one in Bob's pic. The VA guys believe very strongly in recirculate-only setups, none of their units are set up to pull fresh air.
I think we all want to know what he's done there. 8)
Posted by: Chris H. Dec 17 2013, 02:05 PM
Ah OK. I was trolling all his old threads...we'll just wait then!
Posted by: gryphon68 Dec 17 2013, 02:14 PM
The unit you linked is one of the Vintage Air under-dash units; very different from the one in Bob's pic. The VA guys believe very strongly in recirculate-only setups, none of their units are set up to pull fresh air.
I think we all want to know what he's done there. 8)
That is the picture/link Bob originally posted http://www.914world.com/bbs2/index.php?showtopic=110974&st=52#.
Posted by: CptTripps Dec 17 2013, 02:17 PM
I'm looking at this, thinking it may work well.
http://www.summitracing.com/parts/vta-506101?seid=srese1&gclid=CNi57s-JuLsCFYlDMgodzAYASA
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Posted by: badmiata Dec 17 2013, 02:34 PM
I have seen the under dash ones. Renagade, Pelican and what not sell them but its a whole kit compressor and all. I would be happy with something like that if I could use the compressor from the subaru enigine.
Posted by: ThePaintedMan Dec 17 2013, 02:40 PM
Bob's setup is really cool. Would love to find out what it is exactly, but also how he figured out what would work there.
On another note, someone with CAD experience and a 3D printer could probably design something similar, once the proper heater core and fan were identified. 
Posted by: BIGKAT_83 Dec 17 2013, 03:27 PM
Is this what you used Bob?
I was going to use that one in the Subaru car but it ended up that Im going to use it in my LS1 car.
The unit I have in the blue subaru car is a aftermarket evaperator for a Mustang II
I got it brand new at a Hot rod swap meet a few years ago. It was a hell of a buy less than $50 bucks IIRC.
Trust me this is not a bolt in job....
Bob
Posted by: andys Dec 17 2013, 04:08 PM
I have seen the under dash ones. Renagade, Pelican and what not sell them but its a whole kit compressor and all. I would be happy with something like that if I could use the compressor from the subaru enigine.
I got my under dash unit from Hot Rod Air (now defunct) and didn't have to buy a "kit." My under dash has heat as well.
Andys
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Posted by: 914skraper Dec 17 2013, 04:18 PM
So, challenging one of the basic assumptions, it occurred to me that one could surround your Subie exhaust with some stainless sheetmetal, add the heater valve box thing from the 914 heat exchangers, and blow exhaust-heated air through your stock heater system.
Goofy idea? Sure, but it saves running coolant hoses to and fro... 
Posted by: mikesmith Dec 17 2013, 05:11 PM
I have seen the under dash ones. Renagade, Pelican and what not sell them but its a whole kit compressor and all. I would be happy with something like that if I could use the compressor from the subaru enigine.
Vintage Air will happily sell you all manner of individual bits and pieces. There are a number of other similarly-sized under-dash units with every combination of heat, cooling and defrost.
Posted by: Chris H. Dec 18 2013, 09:47 AM
I saved all of the SVX hvac system hoping to use it and the wiring harness. Even the dash vents and dash top and stuff just to understand how it worked before....would take a lot of work to integrate into the 914 but will try to figure it out someday. I'd hide the control panel somewhere so you can't see it...under the center console I have to build or the drivers side arm rest....
It's just this part....
Posted by: ruby914 Dec 18 2013, 10:47 AM
So, challenging one of the basic assumptions, it occurred to me that one could surround your Subie exhaust with some stainless sheetmetal, add the heater valve box thing from the 914 heat exchangers, and blow exhaust-heated air through your stock heater system.
Goofy idea? Sure, but it saves running coolant hoses to and fro...
I tried that and didn't come up with enough useable exhaust. I still think it is a good way to preheat the air like JRust did. For more goofy ideas see my signature.
CptTripps, the Vintage Air Gen ii looks like what I wound up fabricating and put to the FWD left of the motor compartment. It looks like a great unit but the outlet holes look a little small. I used a 3 speed 944 blower and it is working great. It could be a bit more compact.
BIGKAT_83's got
for clean. I want to know more...
Posted by: JRust Dec 18 2013, 11:29 AM
I have a unit that came in a Rotary conversion. I think it's similar to the fresh air vent Mark is making. Except it had oil & water filtering through it. It also used the stock fan. Kind of fugly but very functional. Also pretty easy routing as it sits in the engine bay. So short lines going to your motor.
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Posted by: jaxdream Dec 18 2013, 01:05 PM
I have a unit that came in a Rotary conversion. I think it's similar to the fresh air vent Mark is making. Except it had oil & water filtering through it. It also used the stock fan. Kind of fugly but very functional. Also pretty easy routing as it sits in the engine bay. So short lines going to your motor.
With this setup , you are pulling air from the engine compartment , not exactly non-ordorus . Getting fresh air to the inlet would be a little less smelly perhaps , but a easily doable system as it appears .
My $0.02 .....
Jack
Posted by: andys Dec 18 2013, 01:16 PM
Just an opinion on drawing fresh air from the engine compartment on a conversion car. Unlike the stock 914, where fresh air is drawn from the top side of the motor/engine tin through the engine grill (fresh, un-contaminated source with constant flow), drawing air from the engine compartment on a conversion car (non-Porsche) and blowing it into the cabin is potentially dangerous. I'd be mostly concerned with CO, aside from oil fumes, or fuel vapor.
Andys
Posted by: JRust Dec 18 2013, 05:56 PM
Just an opinion on drawing fresh air from the engine compartment on a conversion car. Unlike the stock 914, where fresh air is drawn from the top side of the motor/engine tin through the engine grill (fresh, un-contaminated source with constant flow), drawing air from the engine compartment on a conversion car (non-Porsche) and blowing it into the cabin is potentially dangerous. I'd be mostly concerned with CO, aside from oil fumes, or fuel vapor.
Andys
Sorry there is a tube missing in the pics. It attached to the fan & pulled air from a vent in the side of the car. So no engine fumes. Having said that I did not ever use this system. Just liked it's overall concept
Posted by: mgp4591 Dec 18 2013, 10:24 PM
I saved all of the SVX hvac system hoping to use it and the wiring harness. Even the dash vents and dash top and stuff just to understand how it worked before....would take a lot of work to integrate into the 914 but will try to figure it out someday. I'd hide the control panel somewhere so you can't see it...under the center console I have to build or the drivers side arm rest....
It's just this part....
I'm thinking that's the way to go also since I've picked up a low mileage, working in every respect SVX. It would require alot of under dash welding of tabs, etc. for mounting and such but certainly doable. The SVX has quite the alluring dash setup- not the traditional 914 look by any means but I'm not looking for a restoration- I'm looking for a comfy, full functioning coast to coast cruiser. Mid engine, water cooled 300 hp GT car...
Posted by: nsyr Dec 19 2013, 07:28 AM
The svx evaporator and fan assemblies are too big to fit under a 914 dash.
Posted by: partwerks Dec 19 2013, 07:47 AM
I have the under dash unit from Renegade.
I'm wondering if it loses some heat running the lines under the car, as it is not real hot. I did wrap the lines with some insulation from Menards to help out.
Posted by: Chris H. Dec 19 2013, 08:03 AM
Re: the stock SVX unit: They are BIG that's for sure. It's a big cube in stock form and could definitely not sit under the dash comfortably without modifications. My dash will be empty in the middle since I took all the manual heater and fresh air stuff out so there may be room for it (or some other system) to reside partially up inside the dash. I'm so far from doing this though...really just speculating with no actual knowledge at all 
.
Posted by: nsyr Dec 19 2013, 10:01 AM
I hear you. I saved all the hvac stuff from my svx, that's how I know. What would be ideal is a unit that could fit in the existing fresh air blower area. That way all the original vents and defroster vents could be used.
Posted by: Chris H. Dec 19 2013, 01:07 PM
I hear you. I saved all the hvac stuff from my svx, that's how I know. What would be ideal is a unit that could fit in the existing fresh air blower area. That way all the original vents and defroster vents could be used.
I figured you were ahead of me on this one Andrew. Yeah IDEAL for me would be something you could stuff behind the dash so you couldn't see it and the car just appeared fairly stock using the stock vents as you said. Once you remove the stock fan controls and radio there is quite a bit of room back there (under there...?). Then use electronic controls like the SVX has so it could be controlled somewhat remotely. Easy to say...hard to do.
Posted by: okieflyr Dec 19 2013, 09:58 PM
I've used McMark's system for 7+ years now and have found it to be very effective.
I also installed a "T" on one side of it to aid in bleeding the air out of the cooling system.
Modern heat without the burnt oil aroma...
Posted by: CptTripps Mar 6 2014, 01:01 PM
I ordered this one today. I'll let you all know what happens when it shows up and I try to fit it in there.
http://www.summitracing.com/parts/sum-991102-1/overview/
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Posted by: sixnotfour Jun 25 2014, 12:25 PM
the other benefit to AC is that it dehumidifies in the wet months
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