The BN4 is a basically cylindrical  object, roughly 20" long, and about 9"
in diameter. It could be used as a stand alone if you have all the
controls, although it was designed to work in conjunction with exhaust/heat
exchanger heaters. You can mount it just about anywhere out of the weather.
You can make bread in a car heated with a BN4.

The BA6 is (in my knowledge) a little more advanced. It is a flattened
cylinder (making an elliptical tube) about 36" long. It is designed
specifically for the 1972-'79 bus, and the 1980-1983.5 air cooled Vanagon.
You *MIGHT* be able to use it with other things, but I think it would be
tough. It is designed to mount in the center under floor area between the
front axle and the rear axle on both models. You can bake New-York style
pizza in minutes in a car heated with a BA6.

Both use a lot of electricity, and are designed mostly as a "pre-heat" or
supplemental heater for the cavernous vans, and leaky VW Thing. The VW 411
and 412 also came fit with a BN4. They both *can* be used when the motor is
off, but I'd want a big fat auxiliary battery if you were going to practice
this.

If you get a good deal on a BA6, I might be interested in one. Lemme know.

G. Matthew Bulley
Director
Bulley-Hewlett & Associates
www.bulley-hewlett.com
Cary, NC USA
888.468.4880 tollfree

-----Original Message-----
From:   EMZ [SMTP:vw4x4@FYI.NET]
Sent:   Monday, October 04, 1999 2:27 PM
To:     vanagon@GERRY.VANAGON.COM
Subject:        Gas heater question?

HI listies,

    Does anyone know the difference between the BN4 and the BN6,
VW installed, gas heaters? Is there any difference in what people
call a heater booster/assist, and a regulator heater? Where in the
Vanagon were these heater intalled? Anyone have any pic's? I have
a line on getting several of these things, but I'm not sure what
I really have here? These maybe just for assisting an existing
air cooled Vanagon setup. I'm not sure if these would be useable
as stand alone units? Any info. would be appreciated.

                                            Eric

            Eric                   86-VW4x4
            vw4x4@fyi.net          72-240z
            Pittsburgh, PA USA     1936-Chrysler