BN-2 Gas heater & big gas tank install

Bigger Gas tank and gas heater install: wanted more driving range, and wanted to do this in conjunction with the gas heater install as I wanted the gas heater installed in the front trunk and duct the heat into the interior under the dash using added A/C outlets. Added pics are in my folder so you can get a better idea of how I did this project. Once I got the gas tank, I chopped about a 6

It looks factory-great. I a question for you-does that model bn2 need a return fuel line back to the tank to route excess fuel back? If so where did you plumb it to, it's supposed to return over the fuel level.
(I, sure you know this but some heaters have it some models don't). One other thing, that fuel line in the pic under the tank, where is that headed it looks a little tight.
What a beautiful,simple, clean install---nice!

P.S. Get the timer and your car will be ready and warm for you.

Bruce, I am refurbishing a BN-2 also(courtesy Tom Dewalt, thanks, man!), and I do not see where a fuel return would come from on my unit. I have looked at all the schematics online and was a little confused as they do show the return. So you are right, some have it some don't. All I need is a new glow plug(hint, hint). There is a Canadian company on the web that has them, but I haven't found them in the states. I plan to install my heater on the firewall, behind the steering and suspension components. It will end up on the passenger side of my Spyder.

Doug, nice install! I will be cribbing a few of your ideas, I like the flexible ductwork. I had also thought about PVC drainpipe, and installing a few defroster ducts for the windshield.

Some heat and one of those windblockers at the rear of the cockpit would make my car a little more useable, especially on those cool nights. I have no soft top, nor do I plan on ever having one.

hey Danny - if you need - you can ship the glow plug to me and i'll send it to you (if the company won't ship tot he US)

I put a B2 in my speedy. it's a little smaller / less heat, but still a huge output of heat.

Doug: what wrap did you put on the heat tubes?

oh and be very careful with a full tank as your heater is slightly below the gas tank high point. the gas will drain through the heater. ask me how i know. :(

Danny, here

I had this bookmarked, may provide some clarity for both models:
http://www.shoptalkforums.com/viewtopic.php?t=122697&highlight=ebersp%E4cher
(As a note, I believe I have seen "supplemental" data for these heaters posted as well, ie, revisions, updates?) Good luck.

Danny, Paul, Bruce....Part 2:
I didn

Part 3 on BN-2 gas heaters...or any Eberspacher gas heater:

A tip on using it if you aren

Paul, thxs for the tip! the later style rotary pump has a ball check valve that "should" prevent it from getting fuel from a full tank where the unit is mounter belwo the top of the tank, but I'll keep an eye on it next time I fill up. A quick test is easy: pull the cover and remove the gas heater fuel supply line and see if it's getting fuel. Quick test and quick answer! Will do ....I hope you found / smelled your situation before you turned on the gas heater!!!!
Doug

the pump line didn't back flow - it was the return line that did. ~3L of gas was on my garage floor. luckily i didn't turn anything on.

Is it possible to have an early heater without the fuel return? I can't see where that would come from on mine. The electric pump is mounted right to the heater as well as the regulator. Will post pics tomorrow if necessary.

Paul, I have the later BN-2, so only one fuel line...and no return line.

The wrap that I used on the 3" gas heater outlet was an automotive product that I bought through Summit Racing. It comes in a sleeve as I recall perhaps 3 feet x 5 feet and is used on automotive floors and firwalls to insulate from heat sources. It is a 3/8" thick insulation that is faced on both sides with a heat reflective foil skin. It can be cut with shears. I used industrial grade wire ties to hold it in place around the furnace tubing. I also used asbestos exhaust header high heat resistance material 1/8" thick to shield the gas heater exhaust pipe under the trunk floor. I also got that from Summit Racing. Check their website @ summitracing.com.

Where you live in Canada, you're probably well versed on Eberspacher gas heaters!
Doug

Danny, I made a "windblocker" out of 1/4" Lexan for my speedster after seeing some of the manufactured models for various sports cars. In my opinion, it helped somewhat but did not make the big difference I thought it would, so I really don't use it... and it doesn't go with the look /styling of the speedster.
Doug

Danny, Eberspacher may have made an "intermediate model" BN-2! If there is not return line fitting on the regulator or gas heater body ( usually at the point where the fuel supply goes to the inlet fitting near the glow plug..), then bench test it by
(1) wiring it up and using a fuel supply to let the Hardi pump work and see if it runs. Wire and Hook up just the pump alone and see if it pushes fuel out somewhere for a return line. If it doesn't ( no fuel leaks ),
(2) wire up the gas heater & fuel pump to a strong battery and fuel source and try it somewhere outside. Once you've got it wired, you should simultaneously have the fuel pump clicking and hear the gas heater inlet fan spinning. Check to confirm that the glow plug is working by removing it and hooking up a power & ground wire momentarily to see if it gets hot. They get REAL hot so don't power it for more than a few seconds...and don't hold it in your hand...they get red hot fast! If all that checks out, put it all back together and see if it fires up and ignites. it takes maybe a minute or less to actually "ignite" after you turn it on. it will sound like a small jet engine and produce hot exhaust out the pipe at the bottom, and hot air out the end of the heater -- opposite the spinning fan. You'll likely need to prime the pump and supply line to the gas heater first after confirming the Hardi pump is pushing fuel. You may also need to reset the red lever on the relay once or twice if it's been sitting for years not being used.
Good luck...keep a fire extinguisher nearby until you get it all sorted out and know how it works, etc.
Doug

Daniel P.---the ones with the return line have a funky triangle shaped
manifold thingy right at the fuel entry point. The fuel line from the pump enters this with "thingy" and sends fuel into the heater nozzle/jet, the excess fuel is ported from that"thingy"(manifold) is ported back to the tank above the fuel level. When I was "bench testing" mine I found that if that "return" is blocked it will not run.
I will try and find a pic of the "thingy". If you don't have it I guess yours is the later model.
This model BN2--no return. Pressure is regulated right before the nozzle(later model)--BN2
http://web.telia.com/~u11107929/BN2_en.gif

This is the earlier model B2 showing the return
http://w1.111.telia.com/~u11107929/B2_en.gif

Here's a downloadable vw heater repair manual
http://www.aircooledheaven.com/blog/Article/12.html

A lot of info here
http://w1.111.telia.com/~u11107929/html/heating.htm

Bruce, thanks. I have those links bookmarked now.

I guess I have the later model, then. It has the Hardi pump mounted to the heater, the pressure regulator between the relay and the safety switch, no fuel return anywhere. It is wired just like the late-model unit with the link, looks like the diagram also.

I completely disassembled it, cleaned it, and put it back together. It has some surface rust on the outer housing, but that's it. It needs a wiring cover and a glowplug. The fan runs smooth as does the fuel pump. I had to clean the pump, regulator, jet, and combustion chamber. Everything is looking good except some broken insulation and bent connectors. Not a big deal at all. I should be able to test it as soon as I get a new glow plug.

Well, I got a used glow plug from Martin Allen off the samba. Bolted it up, made a test stand from some sawhorses, and had at it. First, I disconnected the glow plug and primed the pump. I pulled the regulator output hose off the "jet" until fuel came out. I had disassembled my Hardi pump and cleaned and adjusted it, 2.5 turns out. Hooked up the fuel line and glowplug, started the car(my Subie), and then turned on the heater. The glowplug draws 10 amps, so it is best to have the car running.

Within 20-30 seconds, she fired right up! After another few seconds, the fan speeded up to full, and the juice to the glow plug turned off. It smoked a lot for a while, but after ten minutes or so it settled down, I must have disturbed a lot of crap in the combustion side when I cleaned it. I let it run for a while, then switched it off. The flame cut off as the fuel pump was now off. You could hear the roar of the flame slowly fade and disappear as all the gas was burned off. The fan ran for another minute or two, then shut off. The inside of the heater was down to 65 degrees at shutoff, which is excellent.

The only repair I had to do was braze the bung for the flame detector switch back in place, it appeared to have been broken during shipment to Tom. It didn't look like it was boxed very well.

So I will bench run it some more, just to make sure things are ok. Output is about 200 F, at 50 F ambient. Then I will figure out the install, not as easy as a speedster, less room in a spyder. It will either go in the front well down low, under the dash(yes I've seen them there!), or possibly in front of the firewall near th front suspension. I would build an aluminum box to protect it from water spray, of course. A fellow named Mark put one in a Beck Spyder down low in front of the beam, but that area I need clear for my towbar. I would need to mount it in the front trunk, I think. I will be working on this next weekend for sure.

I really like the way you installed yours, Doug. Where did you get the 3" flex tubing, an HVAC supply? Also, do you have a spare wiring cover? Mine didn't come with one, be happy to purchase one.

I must say thanks again to Tom Dewalt, I will try to put this to good use!

Also, I have a Halon firebottle I have never installed. It has three jets, one for each carb and one for the heater, this WILL be installed, hope to never need it!

Danny, the flex exhaust should be available at a local hardware store...it's a fairly common item: 3" diameter that's used on monitor kerosene heaters, etc. Lowe's / Home Depot should also have it in 3 foot bendable lengths. You can wrap it with various insulation to keep the heat going to the cockpit versus lost thru the wall of the tubing...depends on how much "routing" you need to do to duct the heat to where you want it. It throws enough heat so unless you're trying to insularte it from something nearby, you probably don't need to wrap the tubing. Where's it's alum looking, might look nice "as-is" in a Spyder. Use an A/C adjustable ball outlet(s) so you can direct the heat to where you want it....any A/c shop or mail order A/C supplier should have these. Nice job on overhauling the heater and ensuring that the various safety switches work correctly.
Doug

Danny, the plastic top wiring cover is a little harder to find...check theSamba (www.thesamba.com ). Sorry, I don't have a spare one of those. They are model specific so get the one that fits.
Doug

Thanks Doug. If I install it underneath the tank by the front suspension, I won't worry about a wiring cover. It will be encased in an aluminum box.

I will check samba or ebay for a cover if I need it.Here's a couple of pics of it running, even though you can't see the heat pumping out!

Hi Daniel, Love the test cell! But get a smaller gas supply, preferably sealed to prevent gas fumes from floating off and getting ignited by a stray ignition source. As you have already found out--they don't burn much fuel. How about a mustard bottle? Squeeze type of course.I don't want to rain on your set up at all but I have had two friends hospitalized/skin grafts etc...this year for vapor explosions.
That being said--I love to play with gas--great stuff but be careful.

Here's one for $20
http://www.thesamba.com/vw/classifieds/detail.php?id=738790
or a heater with it for spare parts for $45 (you probably paid that for the glow plug)
http://www.thesamba.com/vw/classifieds/detail.php?id=720315

I don't know what draws me to these - I hum Elton John's "Rocket Man" as I look at them!

Danny,

Have not be on the site much, but I'm happy to see you did something with that heater! I must say no thanks are required. the heater was my thank you to you for all your help when I was in need. Please let me know how it turned out for you.

Tom

Well, I've bought all the ducting and such, but haven't installed it yet. There is a possibility I may install it in my 1972 911 project, as I am thinking headers on that one, instead of the stainless steel heat exchangers($$$$$). It shouldn't be too hard to install the heater to duct into the plenum on the 911, as it already has heater/defrost ducts and a fan.

I just wonder how much use the heater would be in an open car, like the Spyder, where all the heat would just pour out the cockpit.

Danny, the gas heater makes a huge difference even in an open car like your spyder: it'll add more late season - early season seat time. Aim the outlet(s) at the drivers side and you'll really notice the heat output aimed at you. I have a speedster that I much prefer to ride top down as long as I can until outside temps really fall (along with hat w/ear covers, gloves, fleece jacket ).
I also put heated seat inserts (bottom cushions and backs on both seats ) which also adds alot of direct body comfort. It's just amazing how much heat these gas heaters can throw.. even into an open cockpit. I don't bother with the top on cool- cold days here in New England: I just turn on the gas heater. If I put the top & side curtains on/up it's an instant oven and I have to quickly shut the gas heater off or I get cooked. Don't worry about heat loss in the spyder, you'll really notice the heat from a gas heater. My two cents...I'm just saying.....
Doug