Gasoline Heaters, 914's and buses Options

[Randal]

Did 914's and buses have gasoline heaters and if so where were they and how did they work?

Love to see a picture if anyone has one.

[aircooledtechguy]

Eberspacher made the heaters for the VWs. They have since changed their name to Espar. Do a Google image search for Eberspacher models : BN2, BN4, BA4 and BA6 and you'll see all the models they used in VWs. They now make models similar to the BN2 & BN4 models Called Airtronic 2 & 4. The website doesn't list it, but they ARE available in gasoline as well; not just diesel.

They are very well designed units (even the early ones in Beetles and buses). They are just like stock HE on your exhaust and work off the same principal.

Basically you have a S/S inner flame chamber where at one end, a small amount of fuel is mixed with incoming combustion air by way of an electric fan and inner vanes. It passes by a glow plug that ignites the mixture causing the s/s chamber to heat-up. There is an outer chamber that encases the inner chamber where a large volume of air is passes by another fan. Add ducting into the car and Viola!! A warm interior that is independent of the engine running and is much warmer than the stock HE ever could be.

Just found a video that explains it better than I can. . .

There is a lot of miss-information out there claiming that these heaters are dangerous and "explode" etc, etc, etc. Those are wives-tales retold by folks who have never owned one or even understand how they work. Eberspacher units have, since the early days, had safety switches, circuits and over temp detectors that cut power to the fuel pump if they detect an over temp condition. They also have pre-run mode for about 20-30 seconds before igniting AND run-on mode of 20-30 seconds after the fuel pump is cut off which purges the flame chamber of fuel vapors so they are safe.

The VW Beetles, Type-3s, Ghias (all w/ BN2) and Things (BN4) all had their gas heaters mounted in the trunk on the left-hand side. Buses had their heaters mounted either in the left side of the engine compartment when using a BN4 (from the 50s - '78) or under the bus when using a BA6 (from '79-on through the air-cooled Vanagon years). In all those cars they were only an option in the U.S. The Type-4 (411/412) was the only car where the gas heater was standard equipment (BA4 model). It had it's heater mounted above the transmission. This hearer was only classified as a heater "booster" since all air coming into the heater first came through the stock HE, but it could run independent of the motor and was a true gas heater.

[Mark Henry]

There is a lot of miss-information out there claiming that these heaters are dangerous and "explode" etc, etc, etc. Those are wives-tales retold by folks who have never owned one or even understand how they work. Eberspacher units have, since the early days, had safety switches, circuits and over temp detectors that cut power to the fuel pump if they detect an over temp condition. They also have pre-run mode for about 20-30 seconds before igniting AND run-on mode of 20-30 seconds after the fuel pump is cut off which purges the flame chamber of fuel vapors so they are safe.

I guess watching my dad's '67 go up in flames in the middle of a Sears parking lot, on new years eve, with 4 fire trucks and police and a large crowd gathering was just a figment of my childhood imagination.

The "old wife's tale" comes from the late sixties when VW tried to place the gas heater above the tranny. Many rusted out, spewed gas and went up in flames. VW abandoned placing them there shortly after that do to liability issues and put them back in the trunk.

It was fun watch everyone hit the deck when the tires blew. (IMG:style_emoticons/default/wink.gif)

[aircooledtechguy]

I guess watching my dad's '67 go up in flames in the middle of a Sears parking lot, on new years eve, with 4 fire trucks and police and a large crowd gathering was just a figment of my childhood imagination.

The "old wife's tale" comes from the late sixties when VW tried to place the gas heater above the tranny. Many rusted out, spewed gas and went up in flames. VW abandoned placing them there shortly after that do to liability issues and put them back in the trunk.

It was fun watch everyone hit the deck when the tires blew. (IMG:style_emoticons/default/wink.gif)

I will defer to your experience with your dad's car going up in flames; you were there, I wasn't. (IMG:style_emoticons/default/beerchug.gif)

However, in my experience with VWs, 99% of all fires are due to fuel hoses cracking and spewing raw fuel which causes a fire, NOT a malfunction w/in the Eberspacher heater itself. There's a big difference. Like all fuel hoses, if not maintained and changed regularly, you will have a fire. The other 1% came from fuel hose nipples coming loose. I've never seen an Eberspacher heater as the cause. Not saying it has never happened, I just think the heaters get the bad rap for the real cause which is faulty fuel lines.

What I was getting at was what McMark more eloquently stated; when well maintained, they are safe. I can't say that about the aftermarket Stewart Warner heaters though. They do not have the safety features of the Eberspachers and did start a few fires. Personally speaking, I would never use or install a SW heater.

What cars, other than the 411/412, did VW put the heaters above the trans?? In the U.S. they never did, ONLY the 411/412 and buses with the BA6 had them under the cargo floor. . . All the BA4s and BA6s that I have pulled from under the cars have been in pristine condition (once the dust was removed).