Using the oil line to heat the car cabin?

e911S · 09-06-2007, 03:53 AM

HI
as anyone ever attempted to redirect the oil flow into a radiator (with docks and fan) to be used as a heater for the car?
I`m thinking about using some trunk space to achieve this, as some previous owner took the heat exchangers out.
The intend is to drive my '77 911S to the ski slope, therefore some reliable heating system would be welcome.

any thoughts?

e

David · David's Garage

The problem is in the winter when you need the heat the car doesn't need to get rid of it and may even have the oil regulator closed. In summer when you don't want it the car could use the extra oil cooling. With the exhaust heating method, the heat's there whether you need it or not.

Rot 911 · 09-06-2007, 05:53 AM

It would be easier and probably cheaper to just post a want to buy ad for a set of stock heat exchangers. Used OEM exchangers are relatively cheap to buy.

efhughes3 · efhughes3's Garage

.....or find a Webasco gas heater and retrofit?

e911S · 09-07-2007, 04:07 AM

From my experience with the infamous Beetle heat exchanger, is that it down`t really work efficiently, is the Porsche any better if 5-10 degrees driving around town?
I know that the motor is bigger but does it translate to better?
Gas heater is a nice idea and I believe that it was at some point an option.
So in the end, Oil heater is out for legitimate reason, I guess the motor is more important than it`s occupants, so it shall keep the heat to himself...

thanks for the replies, they help a lot

e

klaucke · 09-07-2007, 05:37 AM

Having owned both a beetle and 911, I can attest to the fact that the Porsche system works better. In reality, the beetle system also works well if it is in a good state of tune -- most beetles are not. The Porsche heat exchangers (early style, i.e. SSI) have a much larger heat exchanger volume and more header primary enclosed, which aids in heating the air. At cruise with my 74 style heat (fan driven, often referred to as "backdated" heat), the heat was sometimes too much to bear. Webasto is also a great option if you want instant heat before the motor warms up. They also provide a huge amount of Q to the cabin.

carsngolf · carsngolf's Garage

They also provide a huge amount of Q to the cabin.

Please explain "Q". I have an intact Webasto in my '65 but have never touched it. I've contemplated rebuilding and using it but rarely drive the car in cold weather anyway. If "Q" is a serious problem (noxious or toxic) I'd like to know about it.

Thanks

RWebb · RWebb's Garage

Q = shorthand ASTM engineering symbol for heat -- must be what he means

Zef · Zef's Garage

Janitrol is the way to go...

Walt Fricke · 09-07-2007, 12:11 PM

Before racing got in the way, I used my '77 as my ski car (studded snows work very well). Coming off of VW beetles (and, worse, a van) I was ecstatic about the heat. Not quite as instant as what some water cooled engines can produce, but plenty. I had heat going downhill as well as up. That was really nice in the mountains.

The VW drew heat off of two of the exhausts. The 911 gets it from all six, they are larger, more power = more heat, etc.

On a trip in the dead of winter from Colorado to St. Paul and return I found I had too much heat. I had to crack the window, which soon got too cold, but even the most minimal heat setting short of "off" was a little too much. After reading the owner's manual (mine is in German, so I took my time looking at it) I realized that the answer was to use the top dash lever to introduce the right amount of cold air to mix with whatever was coming from the engine.

So purchase a set of '74 or earlier exhausts (headers/heat exchangers) as was promptly suggested. Or an SSI equivalent (some assert these produce even more heat, and since I added them to my 3.0 (formerly using the early good headers until the sheet metal deteriorated too much), and my non-quantitative experience last winter suggests that might be so.

Or buy the Webasto or a similar gasoline fired heater. That will be a lot more work than going back to exhaust heat exchangers, though.

Walt Fricke

lin7310948 · 09-07-2007, 02:25 PM

i have a 71 911 coupe with much moduified sbc...my oil cooler is mounted in the rear seat area in an enclosure fed fresh air by a naca duct in the quarter panel rear window with two 3 inch ducts. it also has a thermostatically controlled fan motor on the oil radiator. i took one of the hoses loose and it was surprising the amount of heat that was passed into the cabin. but, with that said i would be more concerned about the idea of the defrost system! steamed up windows can be a real problem even with an ample supply of wiping rags!!!!however one of the most frigid rides i ever took was in a 72 coupe with no heat exchangers in mid winter in ohio through west virginia on i77. there were not enough service stations to stop at to warm up...

gestalt1 · 09-07-2007, 02:34 PM

i think those webasto heaters burn a lot of gas to work. how about adding electric seat heaters that many upholstery shops offer. you may need to upgrade the alternator however.

patkeefe · 09-07-2007, 03:15 PM

I think that the auxiliary thermostat may not open much in the cold to even allow hot oil to the front cooler. That being said, I am probably going to put a small oil cooler up near the defroster area in my 914 track car, with a diverter valve. That way, on the track, I can have defrost. Also, the track car has no engine oil cooler, just the front mounted cooler.

BTW, I lived in Alaska for five years, and had a variety of gasoline heaters, in various Microbusses and Type III VW's. They work great, but are a PITA to install and especially maintain.

tcar · 09-07-2007, 05:01 PM

Back when I was into beetles, there was an aftermarket kit to put an oil cooler with fan in a cute little enclosure under the back seat, it pulled air from behind the backseat in the cabin and blew it out the footwell openings in the front kick of the rear seat. Friend had it worked great. There was a manual bypass valve to turn it off, and a 3-speed fan switch.

There were times before the 'tunnel', sitting, idling on top of Loveland pass behind a jackknife semi that it would have helped.

Formerly Steve Wilkinson · 09-07-2007, 07:20 PM

Beetles, schmeetles, I think we can put this thread to bed by saying that hoping for heat-producing oil flow through the cabin in a 911 in the winter, en route to a ski area going fast enough that the thermostat will open, is a dream. Fuggedaboudit.

Jack Olsen · 09-07-2007, 07:29 PM

A lot easier to weld on some heat exchanger boxes.

EarlyPorsche · 09-07-2007, 11:32 PM

The easiest thing to do is search for seat heater on ebay. There are these carbon fiber seat heaters that you can just place under your seat cushion for heat. You shouldn't need to upgrade your alternator, they already produce enough. Just make sure your battery is a nice one and you should be fine. They come with the element and switch and you can mount the switch under the seat so everything is hidden.