Help with '65 911 gas heater?!?!

[klober23]

My '65 911 has the gas heater in the "smugglers box" ...I believe thats what its is. I don't know anything about this heater. I am restoring this car and I just want to make sure it works. I know it has been sitting for a few years. What parts should I replace/check over? The car is stripped so there is not a chance to just try it out. What do I need to know? Thanks

[304065]

Wow. Well, the first step is to get the section from the factory shop manual with the wiring diagram and description of system function. You should inspect all the components, wires and hoses, and if they aren't perfect, make sure they are before going any further.

Search here under "webasto" and you'll get a bunch of threads on the subject. A while back I posted a list of all the components: fuel pump, mixture pump, resistor, etc. Each must be tested to make sure it's working correctly.

[NY65912]

Get in contact with Damon over at Series900, he has a very good working knowledge of these puppies.

[emac]

I had one in a Karman Giah (68) and I never could get it to work. About the only thing it did do good was try to kill you. It would belch out flames, smoke, fumes, and on occasion work right. In my opinion get rid of it, they are a fire bomb waiting to happen. Again this is just my 2cents.

[defcon65]

I had one on my old bug, they work about as well as a Coleman stove, except you go hungry. They have two settings: asphyxiate and incinerate. Remove it and dress in layers instead.

[Series900]

ACHTUNG! 911's are very dangerous to drive,Park yours immediatley. Nader had no teeth for german imports and could only attack GM and the corvair.
Do you really believe the techs at porsche had webasto build them heat"bombs" to install in these ill handling very dangerous cars? You guys are something else!
The auxilliary heat worked fine when new, and so did your brakes, wiper motor, instrument lights, turn signals, synchros, all of it! would you walk into an abandoned house of 25-40 years, and expect to hit the reset button on the furnace and get as new results? NO! thats why the furnace guy comes to your house every year, and if you read the F'n workshop manual, the same goes for every component in your car, its called a maintenence schedule. And in the wkshop manual under accesories, the webasto heat system is fully discussed, including a once ayear cleaning and check of all safety items.

one major flaw is in the original mechanical "timing " relay,it is mounted underneath the drain tray of the fresh air intake at the cowl, the 3"x4" steel relay cover would fill with water, rust, and fail to function. This relay is unobtanium. the "carb" with jet key, is a non servicible diaphram, has a small air hole, to which a blunt pin can be inserted to verify fluctuation, but if the rubber is cracked -torn or old, no fuel mixture will be generated. before the "carb', a point operated fuel pump, which clicks away till pressure is achieved, and then pulses intermitnetly. Clean it. after the "carb" is an air pump, it to needs to function, electric motor, and the offset vane "air " part of the pump has to be cleaned, toleranced, light oil, and sealed around the perimeter. The resistor box has to have non oxidized connections, to provide the corect voltage to the glow plug, and, duh, the glow plug has to be good. Inside the gas heater is essentially the inside of your house oil burner, a flame box(heat exchanger), made of stainless steel, and an outer shroud which air is blown by and is sent into the cabin. the shroud has two micro switches which are to be preciseley set to factory spec, operated on a high/low tab of a bimetallic strip. The low temp switch function keeps the glow plug active till a burn is going, the high side is an overtemp kill, shutting down the system. Complicated? its the same concept that heats your house with all the safety aspects. Just that it uses gasoline mixed to a 1:14 stoichmetric mixture, just like the damn engine thats pushing the car, instead of #2, kero, or propane.

As the technology changed, so did the webasto , transistorized parts were installed, which functioned better. At the same time, the not so adequate heat system of the 911 was updated also, cabin vents moved, A/C was incorparated rather than added on, auxiliary blower motors forced more air thru the engine heat exchangers, foot well blowers etc. Face it, the ventilation system of the 911 was always poor, and the webasto worked providing toasty toes and defrosted windows coming down out of the mountains, instead of keeping the revs up trying to force some lukewarm air off the motor from the altenator fan up to dash vents for a peep hole at the base of the windshield.

Mine works great still to this day.

[304065]

I bet you keep the revs up anyway Damon.

Excellent description of the system, BTW.

Roland Kunz once said:

Hello

You guys watch to much hollywood movies and beleive in to much bullsnow.

The first 911 S came with headers and the seperate heater in front. So Porsche could get FIA papers for that setup witch made the 911 more wight balanced and more succesfull on rallys. To shift the wightbalance even further they mountet the BN3 units ahead off the 100 L fueltanks only divided with a thin aluminized cardboardwall. I never had heard that a additional fuel heater caused any problems with fire or let explode cars.
And those things do have shorts or have burner failures and can get very hot. Only if some stupid mechanic overrides the security devices to make a cheap fix those things will start fires or can explode. But this isn´t like hollywood. It just makes a loud bang and all get filled with smoke and the smoke will press out the oxygene and so no fire will start.

It is a similar risk to have a cheap lighter in you pocket starting a fire or explosion and noone even thinks about that.
Grüsse

[klober23]

My intent is to have some fun with life! I don't expect to hit a "reset button". I understand the dangers of this, but you also have to understand something else. Everyone has a passion for something. I want to know what it was like to drive a 1965 911 Porsche from the factory in 1965. As far as parking my Porsche, that will only happen when I die regardless of how (heater bomb). Thanks for the long description. Not completely sure of your intent's here.

[Series900]

Klober, it was not an attack. Its the ill informed that believe these as " bombs "that raise my revs! the heaters work great, webasto still makes them for plenty of applications, coincidently, head to a small airport, take a look at what twin engine planes use for heat, gas burners! Seen any planes fall out of the sky due to heater unit malfunction?

[Series900]

These are reproduction parts I make for the webasto gas heater installed in 911-912. all NLA these days from the factory, prompted me to tool up these three items 901.572.063.30 front stainless Flex pipe with welded fittings- 901.572.061.30 "sound absorber" a dual chamber baffled muffler/silencer
901.572.602.30 "exhaust line" correct slash cut galvanized tailpipe

A picture installed....



Now if I could only get Cramers help in creating solid state reproduction timers!!! hint hint

jumpin jack flash its a gas gas gas!!!! uh thats period correct, non?

[patkeefe]

Gasoline heaters are about as dangerous as the oil furnace in the basement. Most of the time, when they don't work, it is a fuel delivery problem. My Stewart-Warner Southwind units would all clog the burner nozzles (they are identical to oil furnace nozzles, just a smaller orifice), giving a bad spray pattern, and bad ignition. Then, the combustin chamber would load up with fuel. This is where the "dangerous" stigma comes from.

Identify the unit you have. I think there was a third player in the VW/Porsche gas heater business besides Webasto and Stewart-Warner (Southwind). They really are quite simple devices. I lived in Alaska for five years in the early 80's, and everyone in an air cooled car had one.

[klober23]

Ok just had to make sure. Thanks for all your help

[defcon65]

Wow, that's quite the technical dissertation of a misunderstood device most don't pay attention to. Just the other night I was instructing my nephew on the finer points of the slide-rule, the hope being he could 'show off' in front of his soon-to-retire math teacher and receive the benefit of the doubt on upcoming midterm grades.
Anyone want to talk Beta?

[304065]

Damon, I hear you on the heater timer. A single box that incorporated triple-redundant thermocouples to replace the bimetallic thermostat, a thermostatically controlled heater timer, built-in DC/DC converter for the 3.8 volt glow plug voltage, a startup run of the mixture pump and blower to purge the unit before throwing the fuel to it. . . these are all things that could be incorporated in a replica case the same size as the original firing box mounted under the fiberglass drip tray. . . I'm no EE but these aren't complicated circuits, and there are places that will produce PC boards in quantity for like $25 each. . . I'll post my research here.

p.s. Many twin-engine aircraft have Janitrol heaters, because it's difficult to run heated air from a wing-mounted heat exchanger into the cabin. But to an even greater degree than a car, airplane heaters are terribly unforgiving of incorrect operation and maintenance. . .

Accident occurred Thursday, December 11, 2003 in Buffalo, NY
Probable Cause Approval Date: 1/24/2005
Aircraft: Piper PA-23-250, registration: N40259
Injuries: 1 Uninjured.
After landing, as the pilot pulled into the ramp area, he noticed an orange glow at his feet, and notified airport personnel over the radio that he had a fire in the airplane. The pilot brought the airplane to a stop, and airport crash fire rescue extinguished the fire. Examination of the airplane revealed the fire burnt a hole through the fuselage skin in the area of the Janitrol heater, just aft of the left wing root. The entire area forward of the Janitrol heater, including the wiring and plumbing of the heater, as well as the cockpit and cabin was consumed by fire. The pilot reported that his normal procedure for using the Janitrol heater was to turn it off at the same time he extended the landing gear while on approach. The Pilot's Operating Handbook (POH), Description and Operations section stated, "The three positions of the cabin heat control switch are 'HEAT,' 'FAN,' and 'OFF'...It is advisable to place the switch in the fan position for several minutes after the heater has been operating to allow the unit to cool down before it is turned off." The Normal Procedures section of the POH required that the switch be turned to the "FAN" position while completing the Before and After Landing checklists. The Shutdown checklist called for the switch to be switched to the "OFF" position.


The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

The pilot's improper procedure with regard to the cabin heater, which resulted in the over temperature of the heater and subsequent fire.

[Wil Ferch]

Het Emac...you say you had a "Karman Giah"....

Without coming across in a wrong way....How can someone *own* a car a not know it's spelling... "Karmann-Ghia"..

I guess the same deal as calling a "Volkswagen" a "Volkswagon"...

- Wil ( just askin')

[adomakin]

Im going to get myself one of these bad boys and be done with all that silly flap and cable nonsense!

http://www.eberspacher.com/

[emac]

Originally posted by Wil Ferch
Het Emac...you say you had a "Karman Giah"....

Without coming across in a wrong way....How can someone *own* a car a not know it's spelling... "Karmann-Ghia"..

I guess the same deal as calling a "Volkswagen" a "Volkswagon"...

- Wil ( just askin')

Wil
I blame it on age, ever since I hit 56 my mind has gone, and the Ghia was about 30 years ago.

By the way -- Isn't "Het" suppose to be spelled "Hey"???

Ernie[just askin]

[Fl Ted]

I'm going to chime in here for safteys sake.
Considering the age of your car(and heater) there's one other thing I would check, and that's the combustion chamber for leaks! It's mandatory on aircraft heaters I believe every 1000hrs of operation. It's a fairly simple test that is done without removing the heater. Basically the exhaust and combustion air ports are sealed off, and low pressure compressed air is injected into the combustion chamber through a fitting
screwed into the ignitor boss, and a leak-down test is performed. Why?
Can you say "carbon monoxide"?? Just as deadly as a fire, if not more so. I'd rip that puppy out of there and go through it with a fine toothed comb, checking every component, and while apart, you could do a submereged pressure test on the combustion chamber. Once everything is up to snuff,you could re-install the heater and probably have it work flawlessly for years with no worries. Ordinarilly I wouldn't bother with it (I live in Fl, where we only have a/c problems), but I see you live in Co., so it's probably worth the effort for you,if you plan on driving it in the winter. If not, why bother??

[klober23]

Thanks for all the information Ted. My aim is to have this car as close to original as I can. Its will only be drivin about 400 miles or so a year. Maybe take it to some PCA shows down the road. Thanks a ton...I will take your information and put it to use.

[304065]

Yeah, but when you are sitting in the paddock and the judges come by, and ask you to start the engine, and you start it, and then start the Webasto. . . it will take them a month to wipe the permagrin off their faces.