Improved heating for older 911?

[Wrecked944]

Hello,

I recently disconnected the heater hoses than run from the engine to the passenger compartment because my car was blowing blue oil smoke onto my feet. Very yucky. Given that this is an old car and will likely *always* leak/burn a bit of oil, I am thinking of removing the exisitng heating system altogether and replacing it. This seems very do-able since the heater hoses go right through the trunk area and can easily be bypassed. I think I'd just need a 12V electric heater, 2 hoses, and some wire. So I found this product on JCWhitney.com:


http://www.jcwhitney.com/product.jhtml?CATID=171055&BQ=jcw2


So am I crazy or might this provide superior heating and make my car a comfortable winter vehicle?



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Janus Cole
1980 911SC & 1987 944

[feelyx]

So... where are you going to run the coolant lines?

Tim in Sac

[Rustbucket]

?

uh....I think those things were designed to use the radiator coolant from a water cooled engine.
What would you run thru the hoses? Hot air from the heat exchangers or hot oil from some type of bypass?




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Clint
73T mfi coupe

[Wrecked944]

So... where are you going to run the coolant lines?


If you are refering to the A/C, well...I've got a targa so I don't use the A/C. And it never worked well from the start. I may even toss it in the trash with the old heater blower motor.


uh....I think those things were designed to use the radiator coolant from a water cooled engine.


Actually, I believe the one on JCWhitney says it has a built in 12V heater. And if it doesn't, I'm certain I can find one which does - probably from an RV catalog or something like that. I'm pretty motivated to make this work as winter is approaching and it seems *so* straight-forward. My main fear is the current draw.


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Janus Cole
1980 911SC & 1987 944

[Jack Olsen]

The electric heaters barely make a dent in the cold, in my experience, and the load on the alternator was not something I was comfortable with.

The J.C. Whitney heater you linked to needs a water-cooled car to work.

You might want to look into a reconditioned Webasto gas heater, which goes in the smuggler's trunk (assuming you don't have facory air), and was a heating option popular in cold-climate regrions where waiting for the heat exchangers seemed like an eternity.

Then again, having a gasoline burner within a few feet of your gas tank is not an idea everyone is comfortable with, even if Porsche did offer it as an option.

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Jack Olsen
My Rennlist page • My Pelican Gallery page • My Porsche Owners Gallery page

[This message has been edited by JackOlsen (edited 09-07-2001).]

[wckrause]

If you want a heater that puts out about 1200 watts (about the same as a hand held hair dryer), you're going to need 100 amps of 12 volt power! You'll need to add a second (or third) alternator, and it still won't heat your car very well.




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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[Formerly Steve Wilkinson]

Why is everyone so terrified of gasoline heaters? I've flown any number of twin-engine light aircraft--two across the Atlantic, where I really needed the heat--that have gas heaters as standard equipment. If they're so deadly, wouldn't we have Twin Comanches and Aztecs and whatever falling on our heads because of flaming gas heaters? Please. A car you can park.

Stephan

[feelyx]

Have you ever seen or heard of a gas heater burning, exploding,?
I planned one for a winter project this year.

Tim in Sac

[Wrecked944]

Thanks very much for the info. I was afraid that the power required might be too much. Maybe I should consider an air filter on the stock system? I can't imagine I'm the only person who frequently smells oil in his passenger cabin. My car leaks relatively little oil. But when it drips onto a hot surface...well, you know the rest. Has anyone ever *seriously* considered using the oil lines for heating in the same manner that water cooled cars use hot water? Seems a bit nutty to a novice like me - but I am constantly impressed by the engineering and fabrication skills of the members of this bulletin board. Perhaps to others it seems simple and obvious?

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Janus Cole
1980 911SC & 1987 944

[feelyx]

Janus
On my 77 the heater pumps so much smoke into the cabin that you can't see. I had decided to you the gas heater if I can find one that is in good condition.

Tim in Sac

[RoninLB]

200 -220 deg. oil thru a heat exchanger blown into cabin is a creative idea. It would also be a "back up" to main engine oil cooling system. When driving on 6 deg. sloping roads in Rocky Mts. on hot summer days in thin air if oil temp. climbs I could turn on cabin "oil heater" to remove BTUs from engine oil. A little more sweating over my 911 is no big deal. Where can I buy one???????

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RoninLB

[campbellcj]

I have the main unit of a Webasto heater stashed away in my shed. All of the parts and I think a connection diagram are in the early 911 factory parts manual too. I don't have all the ducting, gas lines and whatever else is needed for the complete system.

I might be willing to sell this thing, if somebody really wants to try to get it to work. I might ask you to sign a waiver though!


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Chris C.
73 914 2.0
70 911E Targa
campbell.chris@gte.net

[island911]

Originally posted by JanusCole:
Hello,

I recently disconnected the heater hoses than run from the engine to the passenger compartment because my car was blowing blue oil smoke onto my feet. Very yucky. Given that this is an old car and will likely *always* leak/burn a bit of oil, I am thinking of removing the exisitng heating system altogether and replacing it. . . .

Well I would say it was definitely very wise to disconnect the smoke blowing hoses. However, I don't agree this is the right permanent solution. Fixing the oil leaks will be much easier than redesigning the heating system; and will have many benefits beyond stink free heat.

Oh, on the filtering out the burnt oil. . .


It’s a little yellow froggie. . .that is poisonous!
BTW, nice homepage.

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'81 Platinum Metalic SC COUPE

[Rot 911]

Why not first try to keep the smoke from being sucked in thru the cooling fan? See if the rubber seals around the engine tin and engine lid are in good condition. If they aren't just replacing them might solve your problem.

[Wrecked944]

It’s a little yellow froggie. . .that is poisonous!


That's an awesome picture !! Thanks very much. My neighbors dubbed my car "Froggie." I'm certain they'll be amused by it. Would it be okay with you if I used it on my web page?

And back to heating and controlling smoke...when I disconnected my heater hoses, my P-Tech blocked off the one that attaches to the fan shroud. He said it would prevent the cooling flow from escaping - which makes sense. But I wonder if there is a way to keep it blocked off and get "fresh" air from a different (i.e. external) source to be fed through the heat exchangers. Clealry, I am in full "McGyver" mode...lol...




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Janus Cole
1980 911SC & 1987 944

[island911]

Glad you liked it. Often my attempts at humor are too cryptic.
The ful pict is here: http://ridgwaydb.mobot.org/mobot/madagascar/essayimage.asp?order=34

Well since your in “full McGyver mode” I’ll suggest you use the “supplemental” electric (squirrel-cage) fan as the only fan. And rather than having it feed off the two into one hose (see pict) which suck dirty air; fashion a hose to suck air from the cabin. Perhaps thru the rear speaker shelf. This will recirculate the cabin air and can be done with minimal plumbing.


But I still think fixing the leaks . . well you know.

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'81 Platinum Metalic SC COUPE

[This message has been edited by island911 (edited 09-08-2001).]

[wckrause]

If you fix your oil leaks, the 911 heating system works fine. The only time it's a problem on my car is when I sit idling. With the right wind conditions, sometimes exhaust fumes get sucked back into the engine cooling fan and into the cabin. I'm not sure how you could fix that. I just turn the heat off when I start to smell exhaust.



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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[Roland Kunz]

Hello

Ever tried your factory heat system.

Porsche can make very much heat. The problem is to regulate a moderate hat and some people don´t seem to fix the oilleaks but the same or more money to "improve" the factory heat system.

Gas heaters are very rerstrective in germany and have to be testet by TÜV each 8 years. The test is a inspection from the burning chamber and most buy a new unit for the same money.

Now after driving severak cars with gas heater and working on many cars I never heard of any risks caused by the unit. They do make problems due to low maintance or usage. Today with the TDI Diesel the gas heaters are very comon in german cars as the TDI needs something like 10 mls to heat up and the TDI has 3 glow plugs with some 900 W in the cooling system to speed up heating.

Grüsse

[wckrause]

"And rather than having it feed off the two into one hose (see pict) which suck dirty air"

I modified your picture to show the direction that outside air enters the heating system. It can pick up odors in two different ways. It can suck exhaust fumes from the exhaust back in through the engine cooling fan, or it can pick up fumes from oil that drips onto and into the heat exchangers.


Re-circulating cabin air won't eliminate the main cause of fumes, and wont' provide any fresh air into the cabin (i.e. heavy fogging).

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Bill Krause
'79 911SC Euro
MY PELICAN GALLERY

[island911]

As Bill says; Re-circulating cabin air won't eliminate the main cause of fumes,
. . .unless the fumes are going thru the main fan from external sources ONLY. So unless you know you have only one probelm, such as, oil dripping on to your muffler and then past the engine bay seal into the the main fan; then you are back to "Finding and Fixing" the leaks OR wearing lots of sweaters and constantly be rubbing a clear porthole on your fogged up window.

Ya know, I begining to think you should just find and fix those leaks.
FWIW I was told by the PO (of my 81 sc) that the leaks it had were from the oil tank hoses. After a bit of cleaning and checking oil spots, it turned out the only leak was the gasket around the oil level sending unit.
No big deal. Now I don't have to worry about blue smoke or my car leaving a stain in my friend new driveway.

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'81 Platinum Metalic SC COUPE