Gas heater install in a late squareback

[Piledriver]

(placehholder, still fabbing, no pics yet etc)

Started installing my gas heater in the T3, as the downside of a decent T4 exhaust is complete lack of heat, and it does tend to get cold in Texas at times.
(Might be 20 at night/75 in the afternoon, but averaging it out doesn't work at 6 AM)

I picked up a lovely NOS BN2 from Germansupply, it's very, very nice, and the price was great.

I also have had a BN4 I yanked working out of my trusty 73 bay when I had to put her down due to rust 20 years ago...

My original evil plan was to simply score soem 411/412 ductwork and install it over the trans... but that seems to be all in poor shape or all in use, and the "in the trunk" install blowing hot air on your cold toes is a slam dunk from all appearances, so the holesaws came out today.

As I was eyeballing the installation of the BN2, on a whim I tried the BN4 in the same orientation...
Much to my amusement the Bay bus BN4 fits FAR better than the correct part, and needs almost zero additional weird hardware//easy fabrication to install. (doesn't even need an exhaust pipe extension with a hole in the right place, and bolts ~direct to the inner fender)

The BN4 also is set up to run off a mechanical thermostat w/push/pull cable, and can do 1080-4000 Kcal/hr, the BN2 is pretty much on/off at 2000 cal/hr.(likely moot with the correct tstat/control box)
It will end up in the 914 most likely, the BN4 woudl be rediculous for a 914... and the BN2 is more likely to fit.

One handy thing I discovered today is that large coffee cans are the PERFECT size to fab the outlet/inlet ducts from, perfect slip-over fit on a BN4. (useful as the original plastic recirc duct is brittle as eggshells, and I don't want to hack up a perfectly good output piece for a Bus that goes by the tank)
(pics etc to follow)

[fusername]

looking forward to this as i will likely do the same soon. first i just need to get a square

[itawolf]

hhhmmm A/C would be great in Texas

but I would like to see this tooo

[Piledriver]

I bolted the BN4 in and started drilling many_little_holes for the air ducts, then had to go to work .(nights)
No pics yet.
I'm still considering swapping to 4" duct instead of 3" before I can't return it... The 3" might potentially be a tad small.

hhhmmm A/C would be great in Texas

but I would like to see this tooo

Oh that's coming later if I can find a small enough compressor...
The car HAD AC in it at some point, unfortunately it's all gone except the telltale holes...

With a stock motor I can understand removing it, but I think a T4 could deal with it just fine, esp with modern compressors.

I DO have a swamp cooler at hand, but those really are for looks around here, too much humidity most of the time.

[Piledriver]

Had to use search to find my own thread

OK, lived without heat last winter, lived w/o AC this summer, decided I needed to get cracking and git this sucker in/working before the weather turns yet again...

Picked up a NOS BN2 awhile back, cut the holes out from the late model install manual pattern, and was stymied trying to find factory ductwork w/o buying a complete system, as it seems most folks who yank these just grab the heater, and leave most of the essential goodies required to install it.

Bought some flex hose--- IMHO too delicate for survival in the trunk with other junk, and doesn't flow well.

Notes on the install add some things I figured out...
Install is still a work in progress, but it's working.

Exhaust is extended with a tapered 1 5/8" tube, sealed and clamped with many layers of Tiger seal and a couple hose clamps.
intake is 3/4" heater hose.

The exhaust holes were originally drilled for the BN4, and it is still an option If I go with larger 5" ductwork.
BTW---Coffee cans (metal ones) are ~perfect size for the inlet and outlet on a BN4 for fabbing custom ductwork.

A BN4 has the advantage of having spark ignition and being "throttleable" via an adjustable exhaust thermostat from 1000-4000 kcal/hr.
A BN2 only has a glow plug for ignition and is 2000 kcal/hr., fixed heat output, cannot be cycled on/off gracefully.
The glow plug is only "on" until the unit lights off fully, then the flame is self sustaining.

If a BN2 flames out, it will restart the glow plug and try to do a hot start, but you may get some "bangs" if you don't allow it to cool down/purge first.
A BN4 has a spark plug with integral glow wire, and has no problems cycling on/off to vary heat output.

Did some more browsing and ended up with this for duct:
It does NOT hit the car/gas tank no rattles etc. Fits ~like factory, clears the little kickout in the front for the factory heater duct.
Note:The intake air and hot air connection points to the car are reversed since I have an under dash AC unit to blow the heat around.
(AC now done yet, but works for this for now)

T3-BN2--ductwork.jpg

Making a cover for the rig out of some scrap electronic enclosures:
(only the front part so far cut out, U shaped, slides under the duct/heater with cutouts for the ex pipe intake fuel pump etc)

T3-bn2-cover.jpg

[Piledriver]

This works great, but I get flameouts once i go below ~1/4 tank of fuel.

I put the T in at the fuel tank>feeder pump location, and the heater pump is on the bottom of the heater on my unit.
I suspect I need to move the "T" to the FI return loop, or move the pump lower.

[David, Lule]

Hi.
The BN2 i have as factory installed in my -67 fastback have the box that covering the glowplug etc, mounted in a more upward position. The data-tag is also in the opposite direction.
Is your from a later typ3 t setup (wich I'm not as familiar with) or is your BN2 originally made to fit a '70s bug, 1302 or 1303?

[Piledriver]

I honestly don't know.

As I couldn't source the factory ductwork, I installed it with the exhaust pointed straight down and for my convenience otherwise, as the ductwork was made-to-fit. The "through firewall" holes were cut per the factory pattern in the manual.

Once I "got over" using the factory ductwork, it went pretty quickly.

The way it's set up I can drop in a BN4 as that's what I originally was going to install.
IIRC it wants 5" ductwork.

[David, Lule]

ok.
I didn't have any pics on the heater itself. But on this you can see the exhaust hole in the inner fender It is nor really straight down. (the pipe is missing) and on the other pic a little of the heater (for the mounting angel)





It seems like the one you got is made for an other instalation angle. I doesn't matter, I was just curious what kind of BN2 wich had those differenses.

[aircooledtechguy]

I'm installing a BA4 heater from a 411 into my shop car '67 Square. I've mounted it above the tranny just like in the T-4 and am plumbing it in line with the H/Es like a stock T-4 installation. That way I can have good defrost and good heat where I want it and not just a hot blast at my legs down at the front floor. I'm hoping it works really nice.

[Steve Arndt]

Has anyone used the aircooled vanagon gas heater? I have a couple of those.

In my baja I have a Stewart Warner type 2 heater. It really heats up the car fast. My points for the spark ignition went south once, so back in the day I parallel wired the heaters coil with my engines coil, both triggered by an MSD CDI. You could only run the heater with the engine on, but it worked.

[Piledriver]

I considered putting my BN2 over the trans with recirc via boost fan from a T4 (no heater boxes/engine air)

It would have been better in may ways, but I have plans for that particular space.

The under dash AC unit does a nice job recirculating the hot air, but I need to devise a solution for the defrost.

[Steve Arndt]

Speaking of defrost Pyle, I made a manifold for the outlet of my heater and have four hoses leading up to the previous "fresh air" vents on my car. A fifth larger hose leads do the floor. I built the manifold out of ABS and JB weld and it is holding up just fine. It looks like a dead octopus.
s

[Piledriver]

Speaking of defrost Pyle, I made a manifold for the outlet of my heater and have four hoses leading up to the previous "fresh air" vents on my car. A fifth larger hose leads do the floor. I built the manifold out of ABS and JB weld and it is holding up just fine. It looks like a dead octopus.
s

I'm a huge fan of Plastic Welder, but it doesn't like over 200F... probably not an issue in this case.

I'm actually considering cutting a slit in the top casing on my under dash AC, and covering it with a section of small PVC pipe.
When the vents are closed it would force air out the slit and the pipe would be connected to the defrost plumbing...
(The AC pulls from under the dash and makes an excellent circulator for heat)

I've bee busy last couple days as I haven't had a day off really in awhile, and yesterday was ~20 hours between work and corralling a new welder found on Craigslist.

[aircooledtechguy]

Has anyone used the aircooled vanagon gas heater? I have a couple of those.

I have one of the BA6 Vanagon heaters for my '66 E-Z Camper, but have yet to install it. Those things are HUGE!! I can't imagine one fitting in anything other than a bus. . .