Date: Mon, 14 Oct 1996 14:42:04 -0700 (PDT)
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: "Steven Johnson" <sjohnson@pcocd2.intel.com>
Subject: Re: BA6 heater install and ... (fwd)
So John Anderson says:
>
> Ken Wyatt wrote:
> >
> > Hi All,
> > I have recently acquired a BA6 heater from a junker Vanagon. I
> > pulled the entire setup from head to toe including the fan, furnace,
> > all wiring up to dash including dash switch, pump, coil, thermostat,
> > ducting including the re-circulatory pieces under the bench seat.
> >
> > I was wondering if anyone had any insight into installing this into a
> > Vanagon without a previous heater. How complicated is it?
>
> The Oct-Dec 1995 issue of the VW e-zine FUNKENGROOVIN has an INCREDIBLY
> detailed article on this exact conversion, and I mean step by step 4
> pages excellent. I would strongly reccomend it for anyone thinking
> about a BA6 install in van or bus. For some reason the article,
> Heat The Bus by Jack Reed does not appear in the archive on their web
> site so if anyone wants it email and I'll snail mail you a copy. Maybe
> I'll type it in if I feel really enthusiastic and we could get it
> archived.
>
> John
> vwbus@netbiz.net
>
Well folks, I'm going to repost his report right now so that you don't
have to go diggin'. My apologies to Gerry and the list for taking up
extra bandwidth.
>From: Jack Reed
--
INTRODUCTION
This is being written for all those that want some heat in their
air-cooled vans. It's also written for those that just want some info
on gasoline heaters before taking the plunge, either by doing it
yourself or by having someone else install it for you.
------------------------- OBLIGATORY DISCLAIMER -----------------------
Before we proceed I'd like to offer a few words of advice concerning
gasoline heaters. THEY ARE VERY DANGEROUS AND CAN BURN YOUR VAN WITH
YOU IN IT TO THE GROUND IN A MATTER OF MINUTES. IF YOU DON'T KNOW WHAT
YOU'RE DOING, SEEK OUT A MECHANIC OR DEALER THAT DOES. Sorry I had to
shout, I just wanted to make sure that everyone was paying attention 8).
All kidding aside, these things can be very dangerous if they are
misadjusted or if the safety interlocks are broken or defeated. I have
heard of older units that had no safety interlocks built into them
whatsoever. I would be very cautious about having one of these units
installed in my vehicle for the simple reason that you, the driver, are
then responsible for ensuring that everything is always in proper working
order. If someone else installs such a unit for you, you may not be
capable of determining when a problem with your heater occurs, with
possibly disastrous side effects.
One other note before we proceed. I installed an Eberspacher BA6 heater
in my 1981 Westphalia from scratch, which means that there was no heater
in the van when I started. The rest of this article refers to
the BA6 since it's the only heater I have any direct experience
with. You should be able to draw certain references about general heater
operation from this article but be careful about making assumptions
about your unit if you determine that it's decidedly different in
operation from the BA6.
All comments and observations in this article are from personal
experience and recollections. Refer to the appropriate manual for your
heater for exact specifications, trouble shooting tips and maintenance
guides. This article is meant to be a general info guide only for the
DIY heater mechanic/installer and for those interested in learning more
about their operation.
Before I talk about the installation phase, let's talk first about
general heater operation. A gasoline heater is really a very simple
affair. Basically they are nothing more than a carbureator, since they
employ a simple metering system for fuel delivery, a spark or glow plug
for ignition, a means of delivering intake air and exhaust of spent
gases. Surround the whole thing with safety interlocks and you've got
a gasoline or diesel heater.
Each manufacturer (Eberspacher, Stewart-Warner, Southwind to name a few)
has a slightly different way of accomplishing these tasks. This article
is going to concern itself only with the Eberspacher (or Espar as it's
known in Canada and the US) BA6 which was originally installed in early
air-cooled Vanagons.
COMPONENT DESCRIPTIONS
The BA6 has several different "packages" associated with it. By
packages I mean blocks of components that are installed in certain
specific parts of the van. The most important part of the installation
is, of course, the heater itself. This is a long, flat pancake made of
sheet metal that basically consists of two parts, the inner shell and
the outer shell. Think of it as two clams, one inside the other if
you're having trouble visualizing it. At one end is where the
combustion motor fan, the spark/glow plug, the inlet for the fuel from
the fuel pump and the temperature regulating sensor reside. In the
middle are the flame and overheat switch and at the other end is the
exhaust pipe and engine heater box air inlet.
The combustion motor fan does two things, supply air to the combustion
chamber by means of a rotating, finned fan as well as supply the signal
to the fuel pump and the ignition coil by means of a set of points that
are tripped by a cam on the end of the motor shaft. The Bentley manual
gives directions for adjusting the fuel pump by the number of "ticks" of
the points, but as we'll talk about later, this method is only good for
sea level installations. The fan pulls outside air through a 2'
corrugated plastic pipe that plugs into or connects to a hole in the
rear cross member. Great care must be taken that this plastic pipe is
secured at both ends, otherwise vacuum could be created at the
combustion motor fan inlet by air rushing by. This would cause the
flame that normally is contained in the heater to be pulled outside of
it, which could cause meltdown of your heater, your van and you. At the
very least it could destroy the combustion motor fan, which is a fairly
pricey and rare beast.
As just something else to go wrong (not really), the combustion motor
fan has a little "propeller" on the end of the fan itself that creates a
long flame path in the heater to ensure complete combustion. If this
propeller is not in place because it was burnt off by an incorrectly
adjusted mixture, you'll have to find/buy another. Otherwise it's
impossible to get your heater adjusted properly and you'll find it's
operation intermittent at best, inadequate at worst. I've been told
that these fans are "mated" to the motor and that replacing just the fan
will cause premature wear of the bearings, resulting in a $200+
replacement. This is reason enough to ensure that your heater is
properly adjusted at all times.
The spark/glow plug is just that, a spark plug that sits in the stream
of gas from the fuel pump. It has it's own ignitor or ignition coil
that also gets it's signal from the points in the combustion motor fan.
The spark/glow plug consists of an inner electrode, exactly like a spark
plug and an outer shield that looks like a small, drilled tube. Even
though I've never seen one in action, I assume that once the spark gets
everything nice and red hot, the shield just serves as a secondary
ignition source for the fuel.
At the base of the spark/glow plug inlet is a short metal tube that
receives the outflow from the fuel pump. By having these two points
essentially coincide, the designers ensured that all fuel would be burnt
as completely as possible. Even so, these units were not designed with
emissions in mind, although I have heard of mechanics that used their CO
machines to adjust the fuel pump, hingeing on the 14.7/1 ideal air/fuel
mixture. I haven't been able to convince my dealer to let me use his CO
machine for this purpose yet due to the excessive heat generated at the
exhaust pipe.
Which brings us to the other end of the heater, the exhaust pipe. This
pipe is bent in a 90 degree angle so that the exhaust doesn't shoot
directly at the end of the transmission. About one inch past the end of
the pipe itself is a metal cap, roughly the diameter of the pipe, which
is held in place by two metal straps that connect to the end of the
exhaust pipe. This pipe is there to ensure that the exhaust does not
ignite leaves, etc. that rest underneath the van. There have been
documented reports of this occuring so make sure that your exhaust pipe
is in place and has the cap as well. If the cap is missing or damaged
by some fumble fingered parts yard mechanic like mine was, you can
easily fashion another using pop rivets, iron strap, and a small circle
of 1/16" to 1/8" iron. Don't use sheet metal for the cap, the heater
will burn right through it. An additional benefit of the cap that I've
only surmised and never really researched is it's action as a venturi.
The flow of air between the cap and the end of the pipe creates a
natural vacuum that creates an increased draw of exhaust through the
heater. I'm not sure if this is true or not, but it's likely, so make
sure that your cap is in place.
In the middle of the heater is a contraption called a flame switch. The
purpose of the flame switch is to provide a signal to the control unit
that the heater is up to temperature. This signal is provided by a
micro switch that is tripped by an expanding metal shaft that resides in
the heater's core. The flame switch is tricky to get adjusted properly,
as the micro switch is held in positon by two screws terminated by nuts.
The only way I'v ever been able to get mine adjusted correctly is by
using a propane torch and a DVM. Once I've got the micro switch in what
I think is the correct location, I lock down the screws as tight as I
can get them. Then I set the DVM on the OHMS position and place the
metal rod in the flame from the torch after hooking the DVM to the
common spade clip and the NO spade clip. If the meter shows infinity
when the rod is cool and ~0 when in the flame for a few seconds then
you've got it right. The rod can get red hot pretty quickly while in
the flame from the torch so be careful where you place it when you're
done checking the adjustment.
The flame switch adjustment has been at the heart of 90% of the
problems I've had with my heater, so make sure you get it right. If
you're unclear on what's happening there or how to follow my directions,
write me at the address at the end of the article and I'll give you a
hand with the procedure. The other 10% of the problems have been due to
an incorrect mixture, which resulted in the premature demise of my first
combustion motor fan. This resulted in incomplete combustion of the
fuel and erratic operation of the heater. Information is provided on
adjusting the fuel/air mix for your unit later on in the article.
There is also a metal "button" in a ceramic ring that fits beneath a
clip on the top of the heater. This is called the overheat switch and
it's nothing more than a breaker that will kill power to the heater if
the temperature of the heater's outer "skin" gets too hot. This could
happen if the fuel pump were to lock in an open state, allowing
unrestricted fuel to create a "runaway" situation. It's your final
defense against meltdown so make sure that it's in good condition by
running the checks recommended in the manual.
The two halves of the heater are held together by the use of rivets. If
any of yours are missing, pop rivets can be used to resecure the unit.
The heater itself works like any home furnace you're familiar with
where the actual combustion occurs in the inner jacket (or clam, if
you're still using that image as a guide) which then heats the air in
the cavity made by the second jacket (or clam). The exhaust pipe runs
through this outer cavity to get to the outside of the heater.
Warm air is pushed through this outer cavity by means of two fans, the
squirrel cage on the end of the alternator and the auxiliary fan that
draws air through a hole cut in sheet metal underneath the rear seat.
The auxiliary fan pulls the air from the heater boxes that surround the
exhaust manifold and the squirrel cage fan pushes air through them.
Another plus (besides the added boost of warm air) provided by the
auxiliary fan is that by drawing air from underneath the rear seat it's
recirculating warm air that's already in the passenger compartment.
This means that the heater doesn't have to continually supply heat, it
only has to replace the heat lost to air leaks and convection losses
through the body, roof and floor. I live in Colorado and these losses
amount to a lot when it's 20 below outside and you're scooting down the
road at 65.
The fuel pump is a small, 4" affair that connects to the fuel line after
the fuel filter. Make sure that you get the "tee" for the main fuel
line and the clamps that hold it in place, you'll need them to splice
into the main line. I've heard the fuel pump described as nothing more
than a hypodermic in it's operation because of the way that it squirts
gas down the hose to the heater. It attaches to the cross member by means
of a rubber bushing and a nut and bolt.
At the front of the heater is a temperature sensor. It's a criss-cross
arrangement with a resistor in the center of it. It's used in
conjunction with the thermostat to regulate the heater's output
temperature. The sensor sits in the output stream to the passenger
compartment at the front of the heater.
The final part to the heater section is the belly pan, a long, wide
section of pressed sheet metal that runs from the gas tank to the
transmission and between the frame rails. The belly pan serves two
functions, it protects the heater and it's components from rocks, salt
corrosion, etc. and it traps "some" of the heat produced by the heater.
There's a small door in the center of the belly pan to give you access
to the flame switch. There's also a cutout in the sheet metal to allow
you to adjust the fuel pump without having to remove the belly pan.
I've often thought about insulating the belly pan to reduce heat losses,
but haven't only because I can't figure out why VW didn't insulate it in
the first place. I suspect there's a good reason for this and until I
find out what it is I'll live with the heater in it's present state. If
someone has an insulated belly pan in use for several years I'd
appreciate hearing about it.
Last (didn't I say "final" in the last paragraph?) but not least are the
two short sections of duct that connect the heater to ductwork at the
front and rear of the engine. These pieces of duct are needed to splice
the heater into the old, single pipe that used to carry heat direct from
the heater boxes to your frozen tootsies. The ducts should be in good
shape, with no cracks or breaks in them. Suitable replacements could
probably be gotten from a heating/ventilating shop if the dealer's
prices are too dear.
If after you've got the heater installed and running and it sounds like a
locomotive has taken up residence there in the van with you, the inner
jacket is cracked. You need to get another one since I'm not sure if
such a crack can be repaired. I'm not saying it's impossible, just that
I've never had to have it done so I can't say whether it's possible or
not. In any event, the heater is unusable until you get it replaced or
repaired since carbon monoxide will be venting directly into the heated
air flow to the passenger compartment. Just in case no one's told you
by now, carbon monoxide will kill you, either by depriving you of oxygen
or by causing you to fall asleep at the wheel, resulting in a close
encounter with the back of a tractor trailer.
The person that told me about this sound being produced by a crack said
there's no mistaking it from the normal sound of the heater in
operation. If you're not sure if yours is cracked or not, but suspect
it may be then have a heater/ventilator guy or gal probe the output from
the heater in the passenger compartment with a CO sniffer for excessive
fumes. I can't caution you enough about this. It's better to freeze
then to die from carbon monoxide poisoning and possibly kill other
innocents in the process. In fact, after all is said and done, it's
probably not a bad idea to have someone probe the heated air in the van
for CO as a final check of your work.
That covers the components directly associated with the heater
itself. Let's move to the back of the van now, in the cavity between
the bottom back of the rear seat and the engine. A hole needs to be cut
in this sheet metal to allow the auxiliary fan a place to pull air from.
Make sure when you get your heater that you get the plastic cover and
foam gasket that the fan mates to. You can use the cover as a template
when it comes time to cut a hole in the sheet metal. There are two
"dimples" in the sheet metal that you can drill out to receive the
screws the hold the cover in place. Once you've got the hole cut find
a logical place to hang the auxiliary fan from so that it will mate to
the port that juts out from the cover.
Next you need to replace the ductwork that routes hot air from the
control flaps to the original duct to the front of the cab. These
two units are almost identical, the only difference being a port to hook
the auxiliary fan onto. This is pretty straight forward, just check
that the one-way air flaps in the ductwork are in place and functional,
otherwise part of the pressure from the fan will just wind up fighting
against the pressure from the squirrel cage fan and you'll wind up with
zip for heat. While you're back there it's a good idea to R&R the
control flaps so as to get maximum heated air out of the heater boxes.
The last package of components are those that fit under the dash.
Although these components can be installed without pulling the dash, it
makes for a much cleaner, easier time of it if you do pull it prior to
installing them. There are five main parts to this phase, and we'll hit
them one at a time.
First there is the extension to the fuseblock that holds the two
additional fuses for the heater's operation. Didn't get it when you
pulled the heater? You can use the appropriate sizes in in-line holders
instead.
Next is the timer/thermostat, it goes in a hole in the dash just below
the instrument cluster and to the right of the steering column. If
there isn't a dummy hole already in place try and pick a spot where
you'll have room behind the hole to mount the thermostat. The timer
section of the thermostat allows you to preheat the heater on a cold
Winter's morning. Don't run the heater off the timer more than once
when it's real cold or you take the chance of running the battery too
low to start the engine. Press in on the knob with the "+" on it and
turn it to the right, you should hear the watch mechanism ticking
merrily away. If not then something's jammed the works and you'll need
to take it apart to get it working again. It's not absolutely critical
that this section of the part works, so don't sweat it too much if it's
broken. Normal means of heater actuation is to turn the knob to the
right without pressing it in first, while the engine is running.
Then there's the safety switch, which mounts there by your right knee
when you're sitting in the driver's seat. It has a bimetal relay that
will "blow" if the heater doesn't come up to temperature fast enough or
if it doesn't keep putting out heat after the flame switch rolls over to
it's "closed" position.
After that there is the heater relay which makes an audible "snap" when
the heater kicks on or cycles. That goes over in the area behind the
glove box. Last but not least, you need to replace the heater levers
there in the dash. The replacement lever assembly has a contact on the
right or "HOT" side of the lever that supplies a ground signal to the
electronics package. I suppose that someone could bypass this step and
just install a toggle switch in it's place but care would have to be
taken to ensure that the temperature control lever was in the "HOT"
region before the heater was actuated. Otherwise air from the heater
boxes would be cut off.
I'm not going to go into all the checks associated with these
components by duplicating the work the Bentley technical writers put
into the manual. Suffice to say that you should pick one up and run the
checks that they recommend. If you can't afford the manual (and at $90+
a pop who can?) there are several outfits that will sell you a copy of
the heater section of the manual for around $10. Or find someone who
has a copy that is willing to make you one. I don't have one. Nope,
not me, uh uh, don't ask. Well, I don't know, maybe if you ask real
nice.
INSTALLATION
Installation is pretty straight forward if you take your time and start
sometime in June. If you wait until September when the first flakes
start flying you'll probably make a mistake and fry something that you
can't afford to replace. Try and start early if at all possible.
I performed the installation in three phases: underdash components,
engine area components and under van components. Check your work as you
go and replace anything that looks borderline like rubber boots or fuel
lines. If you have the room and the tools, check each component for
proper operation by hooking them up to 12VDC or by performing whatever
resistance checks you can before installing them. I laid everything out
on my garage floor and made sure that I knew where all the wiring and
connectors went before I started the install. Then I visualized how
everything hooked up, where it was located in/on the van and how best to
route the wiring. Once that step was done, the rest just fell into place.
Uh huh. Believe that and I've got a bridge to sell you. This is a
painstaking labor of love that will easily consume at least three
weekends over several months before it's right. But your
wife/kids/friends/frozen nose will thank you for the time spent doing it
right. I'm sure that someone could install a BA6 faster than that, but
that's how long it took me and I've spent 24 years crawling around all
sorts of vehicles. If your level of expertise is less than that you may
want to start in April (just kidding). I don't feel that this is too
much of a job for anyone with a fair degree of mechanical/electrical
understanding. But you will use all of that knowledge and then go
looking for more, so don't rush the job if you don't have to.
When it comes time to mount a component to the body, such as the heater
or the safety switch, look for little "dimples" in the sheet metal.
This is where you need to drill a hole to accept the screw for that
component. Be careful of punching through whatever is behind the dimple
so that you don't, for example, punch a hole in the van's floor. The
bushings that the heater hang from will probably get trashed by whoever
pulls the heater, mine were. They run around $1.50 each from the dealer
and I'd suggest that you install them as they will isolate the heater
from road shocks and bumps.
Items to check when inspecting a used heater are:
- no worn through rust patches, in fact no holes at all
- no big dents, the inner shell could be collapsed
- good bearings on the combustion fan, with little or no play to them
- points in combustion motor fan are in good shape (pull the end cap to
check them)
- apply 12V to combustion motor fan to check operation, keep your
fingers, hair clear of the fins when performing this step as it runs
at ~7000 rpm
- that combustion motor fan does not show signs of excessive heating and
that the little propeller on the end is intact
- correct resistance on the ignition coil (check Bentley for specs)
- spark/glow plug electrode and shield are in good shape and aren't
burnt or melted away by excessively high temperatures
- apply 12V to the fuel pump, if it doesn't "click" it's probably NG
- apply 12V to the aux. fan to check operation, check it's bearings also
- rubber hoses to/from the fuel pump, replace if cracked
- high tension wire to spark/glow plug, replace if not perfect
- plastic pipe to combustion fan has no cracks and seals well to cross
member receptacle and combustion motor fan inlet pipe
- that flame switch rod is straight, micro switch adjustment correct
- inspect ductwork for cracks, repair with hi-temp silicon, epoxy, etc.
- that all electronic components pass recommended electrical checks
ADJUSTING THE FUEL/AIR MIXTURE
Here's the part you've all been waiting for, adjusting the fuel/air mix
(which is why I put it at the end of the article, naturally). The
manual states that 18.4 to 21.7 cm. of fuel should be dispensed every
200 ticks of the fuel pump. I checked this and the heater smoked liked a
runaway freight train. Due to the nature of the beast, that being that
these heaters are nothing more than big carbureators, they have to be
setup for altitude. Since there's no timing adjustment you can only
throttle back on the fuel to accomodate the lower oxygen density at
higher altitudes. If you're in the mountains (I'm at 5,280') then you
want to keep throttling back on the fuel pump until the heater stops
smoking. Leave the heater at this setting for a week or so then check
the tabs and propeller on the end of the combustion motor fan. If the
tabs, etc. show signs of being burnt you need to throttle back on fuel a
little so as to cool off the charge. If you get things too lean you'll
fry the fan and the heater won't work very well if at all, so keep
checking the state of the fan until you're happy that it's not getting
toasted.
The only other way to adjust the heater properly is by use of a CO
meter. I'd suggest using a length of muffler pipe on the end of the
exhaust pipe so as to cool off the effluent as much as possible.
Otherwise you take a chance of frying the probe on the dealer's $15,000
emissions machine. And he won't be very happy about that. If you can
get someone to let you use their machine, set the heater at 1.5% CO,
which is the ideal stochiometric ratio of fuel to air. I'd still check
the fan a couple of weeks afterwards just to be on the safe side. But
I've already roasted one fan so I'm a little more cautious than most.
Those things are hard to find and you'll pay dearly for one when you do.
That's it. Pick a nice shady spot to do the installation and take your
time learning how the whole thing works and goes together and you
shouldn't have any problems. I can be reached by email at
jackr@fortnet.org if you have any questions about the installation, etc.
Good luck and enjoy your old rolling icebox turned four season Van!
-----------------------------------------------------------------------
Steven
Sacramento, CA
sjohnson@pcocd2.intel.com