ba6 recirculation fan importance

[airkooledchris]

I am nearly 100% done pulling the BA6 from my 81 Vanagon.

had to drop the gas tank to get the wire loom out completely in tact, but did manage to do so.

I am *thinking* about putting this into my 79 bay, but one thing I know im going to have trouble with is the recirculation fan. I haven't pulled it completely from the Vanagon yet as there is a ton of connections for it to splice the cabin air back into the heater boxes and

A. the connections/etc aren't going to be the same for the bay, so id have to fab something both to route into the heater boxes on the baywindow

B. id have to cut and make a port for the fan to draw in the cabin air from the bay

C. the recirculation fan and its connections are so rusted and hardened in place currently that im going to have to cut the brackets off with a small saw just to get them out.

I want to say that this BA6 will work well enough just drawing the incoming air from the stock heater boxes, but will not using that recirculation fan cause any running issues with the BA6 in terms of the wiring?

just not sure if ill need to connect it to 'something' so it at least thinks its still hooked up in order for the rest of it to work properly.

lots of other potential headaches im sure with retrofitting it into the bay, but I did carefully pull every other bit of this system out from the Vanagon.

the parts ill have to fab will be a switch to turn it on, instead of the heater switch-ground that it normally uses and rubber mounting points to connect it to the underside of the body.

any tips, suggestions, feedback or tomfoolery welcomed.

[busdaddy]

You need the fan, not only is the engine fan output not enough the heater will likely overheat and shut off due to lack of flow. Besides half the fun of a gas heater is being able to turn it on and warm up the inside of the bus before you even start the engine
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[airkooledchris]

ok, so it definitely needs it for the airflow, I hadn't considered that aspect.

I suppose it doesn't HAVE to be drawn in from the cabin, but it needs the flow of this fan in addition to the one mounted above the motor in the engine bay.

fwiw it's the exact same fan, seemingly, as the one for the stock baywindow heat, just mounted a few feet closer to the heater.

is the idea that it needs the both of them, or just that I would need this second one (who's original idea is to pull in cabin air) for when I run the heater without the bus running, where that stock heater fan wouldn't be running?

since they are the same fan as one another, I wonder, and assume I cannot, if I could just wire the stock heating fan up to be triggered on when the BA6 wants it - instead of it only kicking on when the stock heat is running.

[busdaddy]

Wellll...... I guess that would work..... your anti return flaps in the shroud would have to be in 100% perfect working order. Already slightly warm air from inside the bus is alot easier to heat and doesn't stink (like engine anyways), drawing from inside also ensures a good flow even if all the windows are rolled up and the door vents are closed.
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Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

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[airkooledchris]

the stock heat in my 79 actually works pretty darn well, especially as to the 'smell' factor. I know what you mean though, my old 75 and 76 both had working heat, but it always had that stench of exhaust to it.

I kinda sorta figured it wouldn't be an smart, albeit easier, thing to bypass in the swap. ill have to see about modifying it to tie into the baywindow system or get the correct baywindow parts for this. just in case ill pull everything else from the van in case I can adapt it.

[raygreenwood]

[airkooledchris]

the BA6 I just finished pulling from my 81 Vanagon doesn't have any particular smells to it at all. The baywindow bus im considering adapting it into has the cleanest smelling stock heat that ive had in a baywindow.

there was some concern that if my stock heaterboxes don't smell very good that skipping the recirculation fan would make that worse, but I don't have that issue to worry about.

I'll still have to see about how to pull in cabin air though, so im not overtaxing the stock heater fan in the engine compartment (or overtax the heater by not providing enough flow.)

at the very least ill use the second fan to provide additional flow

[josh]

I adapted a vanagon BA6 to a bay window years ago.

This is all from memory but...

There should be a circle stamped in the sheet metal behind the rear seat. This is where the hole for the recirculating air blower goes.

The front of the heater should be coupled where the front of the old heating duct was. The flapper valve housing from the vanagon should be coupled to fill in the gap behind. I think I may have trimmed or otherwise modified the vanagon housing to fit (It's been awhile).

Be sure the combustion air intake tube is connected to draw air through one of the holes in the frame cross members. If the tube is left in open air road draft can pull the flame through the tube and catch it on fire.

Someone recently added a BA6 repair manual from 1979 to theSamba archive literature so you can see how all of the parts are oriented on a bay.

The heat these things put out is awesome!

Good luck.
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[Sage79]

I just got my BA6 working this week. (It needed a good relay and the two sets of points cleaned up after getting both fans to run). It seems that the recirc fan puts more air into the system than the engine fan and booster fan combined. I agree with BD's first reply that the BA6 will quickly overheat without it. You may be able to re-engineer it but only if you examine the air flow through the BA6 heat exchanger during all of the design conditions.

The heat is awesome! It will burn your hand coming out the defrost vents!
_________________
Dirk
'79 Westy 2.0FI
'73 Sportsmobile 1.7dual Solex 003Auto - now my daughter's
'77 delux 2.0FI 090Auto - now my son's

[airkooledchris]

[jure-slo]

If you need any specific photos...my '78 bay with stock BA6 is on the car hoist right now because I took the engine out. It wouldn't be much truble to remove the belly pan...
_________________
'79 Bay-window, 2.0, duals solexes, automatic
'76 Triumph spitfire 1500
'86 Polski Fiat
'72 Mercedes W115, 200D

[airkooledchris]

[hazetguy]

there are a lot good pics in the gallery: http://www.thesamba.com/vw/forum/album_search.php?...t_dir=DESC

here's where the heaterbox air enters the heater:

this shows the area where the cabin fresh air is routed into the fan. the galvanized piece to the right of the orange opening piece (which is actually a hole in the firewall) is a piece that is riveted to the opening.

a complete BA6 is one thing i would really like for my bus.
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[jure-slo]

This what you were looking for?

_________________
'79 Bay-window, 2.0, duals solexes, automatic
'76 Triumph spitfire 1500
'86 Polski Fiat
'72 Mercedes W115, 200D

[raymino]

front

rear showing my rubber duct being preserved/protected by duct tape (I'm saving my good one for the big event).

The air circulation blower is also necessary for the cool down or "run-on" phase to complete. If you were running your BA6 at full blast and somehow lost all juice, your BA6 would get quite hot for a time. The air circulation blower keeps working even after you turn your bus off and walk away. Kind of like the electric fan on those water cooled jobs. You need it.

The "air circulation blower" is definitely different from the "hot air blower". I wish they were the same as good BA6 air circulation blowers are verging toward unobtanium. You should get yours checked out and also make sure that rubber duct (round on one end and square on the other) that connects to the air circulation blower is servicable. If not, be on the lookout for one. I think this blower is the weak link in the BA6 system.

I have taken BA6 parts off of vanagons and used them in my BA6. My '79 Westy came with one installed, so I can't help much with that floor duct intake for the air recirculation blower. I think that will be your only issue.

You will love your BA6, even in balmy Eureka. I think you will regret it if you don't stick to the stock BA6 setup, working air circulation blower and all.

Meantime, it's my theory that bus heat with a BA6 installed, but not working (just using the stock heat), is less efficient than the stock heat without the BA6. I recommend that you install one of these ...

view looking to the rear showing the air circulation blower/body connection (coffee can lid duct taped here).

While you are getting your BA6 shaped up, you can use this replacement pipe to see just how much you can get out of you stock heat, following Ratwell's chart. More pics are in my gallery.

Ray
_________________
'79 Westy Headflow Masters 2.0L FI
'87 GTI 16V Sold!
'06 Jetta 2.5 Package 2
'71 Super Marine Blue

[mattcuddy]

[airkooledchris]

I have a thought on how to get cabin air into the BA6, for busses that don't have that big hole cut under the rear bench seat (and without a donor section from another bus)

Why not just take the stock heaters output channel that points to the rear, from under the middle passenger seat - and make this the cabin air to BA6 recirculation point?


in more obvious terms, change this thing from BLOW to SUCK instead:

why the hell not?

If I can do this, I think my next hurdle is going to be fabricating a mount for the actual heater unit itself.

[josh]

[josh]

[airkooledchris]

Thanks a lot for the replies. Ill continue to post back here rather than PM'ing you so others who might tackle this down the road will have more resources...

Im a little confused on the above, did you mean you did cut a hole in the one you have now, or that you would if you ever redid it?

I did save the little plastic screen for the hole that was cut under the rear bench, though the rubber thing that connected the two was kaput and ill have to re-do that part (I think you did the same.)

the points on the bus where the BA6 mounts is definitely a little different than the Vanagon, but ill probably just do what you did and pull the stock setup and just hoist it up there to see what fits and where it'll need tweaking.

I agree on the air-flow thing for the cabin air, when I was mocking it up earlier I saw the way that fan actually works and figured id either have to do it like the Vanagon and cut the hole - or not use that metal vent under the floor, but perhaps use that hole with some kind of cover and screen.

this is what I have, minus the wiring stuff: