So, in the quest for some sort of damn heat/defroster I was curious if this could work.

In the really sh*tty diagram below, a coolant recirculation system that cycles coolant through the muffler to transfer heat from exhaust to coolant so it can be used with a heater core to supply heat/defrost.

I would expect that the tubing passing through the muff would need to be more than a simple tube and more likely an array of small tubes in parallel to better transfer heat.

Is this feasible or should I gently place the crack pipe down and call for help

I like it.

make a large flat "flask" that could be welded to the muffler with inlet and outlets.



And...If you do have a crack pipe, you really should put it down.



KT

coolant velocity in the system is a critical factor....move it slowly and the heat transfer will occur


though in reality, I think a mixture of crack and teuila will make you forget about the cold

What about coiling tubing around the exhuast? You could use some thin stainless steel tubing and coil it over a section of the exhaust piping and then do the same thing.

That might make it easier to install?

-Tony

it would work - but why not just do heat exchangers?

Water might be too efficient - you might run into problems boiling it with exhast gas temperatures.

They must have some really GOOD crack in NJ! If you paid for it use it!!! (this was a shot)

QUOTE (trekkor @ Nov 9 2005, 05:24 PM)

I like it. make a large flat "flask" that could be welded to the muffler with inlet and outlets. And...If you do have a crack pipe, you really should put it down. KT

Harsh...
Well I got a laugh from it.. Sorry..but.. Ok I'm done now.

what's wrong with the stock setup?
aftermarket exhaust?

No stock HE's, hence the quest for something different. I've thought about a gas heater, homemade HE and etc.... Just thought this may work and I had never seen anyone try it.

My setup is a 3.6 with Euro race headers..........

I think it really could work.

reminds me of my freshwater cooler on my old boat motor.


KT

buddies fresh water cooling setup used cold water intake and dumped the heated water in the lake/ocean. a recirculating system might run the temps way high. then how might you stop the heating process? stop the pump: boils water.

probably work as your are not going through the exhaust manifolds but the muffs. probably just have to experiment.

Now if you just ran air tubes thru an exhaust manifold with a flapper valve.... wait, that's a stock setup.

Nice idea,

I would like to see an AC system that acts like a heat pump. I.e., it can heat or cool.

Don't use water, pick someting with higher boiling point. wrap headers with aluminum fuel line and pump away. I bet you could make it work.

Or give the engine to me, I don't drive in the winter

Might I suggest you simply plumb in a small oil cooler, and use it as a heater core. Relatively slow to heat up in comparison, but the simplicity may be worth it??

Andys

It really would be easier to go to your local sporting goods store and buy a case of Sterno. Light one or two and place on floor while driving......














It's been done, but I won't say by who or when.

Sounds like it would work, just have to find a pump that could handle the hot fluid.

Thanks for the replies. So far, it's seems about the right mix between smartass answers and real replies. I appreciate both!

As far as a pump is concerned, there are marine 12v water pumps used for hot water systems(showers,sinks, etc...) that have ratings high enough to handle 220 deg. There are also 12v water pumps made to eliminate the engine driven pump on HP engines, I know they would work but are probably overkill.

I was thinking a small heater core could be shoehorned into the fresh air box and create heat/def in a semi stock manner, without being hokey looking. Use stock fresh air fan, controls, etc... and with heat off it would still act as a fresh air system.

As far as an oil cooler solution, it seems to be the consensus of this board that it will not provide sufficient heat. I think a few folks have tried it unsuccessfully.

I honestly think a gas heater is probably the best solution, but a clean install could be a challenge and I think it would still have that unique smell depending on where you pull the cold air from.

Best of luck but you will need a way increase the pressure in the system to keep the water from boiling. You don't want STEAM heat.

Don't for get a pressure safety valve. The pressure in the system will get VERY high when you stop the pump. You don't want to have the issue of hot fluid leaking in you car;)

I think once you really look into the issues with doing this you will walk away. There are better ways to get heat then to add an H2O system to your car.

Just my $0.02

If you still want to make this work...It can happen but will take some real slick DIY.

Take a look at motorcycle parts. They are small and you can get them cheap from a junk yard. Small radiators, exp tanks, and cooling fans.

You'll probably spend more trying to rig up a hot fluid system, than if you got some GHL or B&B stainless headers with heat. I don't think I'd sell another set of B&B's though, they have problems with fit.

I personally don't think you'll get enough heat transfer to plumb a water system some 26 ft (round trip) and get enough heat to do much of anything.

Sell your headers and get some stainless heaterboxes. They will last longer than you will, never leak "coolant", and you'll be done with it. In the scope of any conversion project, if you need heat there isn't an easier way to go.

I'm thinking you're only going to be cooling the headers and not heating the water enough to be able to heat a core to heat the interior.

Think about a water cooled engine, the real heat is in the heads and that is where the water is heated for the interior heater system. The heads get VERY hot and the water jacket in the heads carries that heat away.

The headers of a 914 don't get as hot as the heads do in a water cooled engine. I think the water will get harm and the headers will be cooled but the water will not be hot enough.

It is a good idea and I think would work if the water was hotter.

Does anyone know if the heater in the Wasserbox (the water cooled type IV) used a heater core and the water off the heads?

Paul

QUOTE (Kerrys914 @ Nov 10 2005, 04:45 AM)

Best of luck but you will need a way increase the pressure in the system to keep the water from boiling. You don't want STEAM heat.

You could use another fluid if boiling becomes a problem. Maybe a light oil. Cooking oil will go above 400 F before igniting. Then you could operate a deep fat fryer in the front trunk. You want fries with that?

Does anti-freeze affect the boiling point of water?

QUOTE (maf914 @ Nov 10 2005, 07:24 AM)

Does anti-freeze affect the boiling point of water?

Duh!

Ever read the back of the bottle?

Back in my 4x4 days I took copper tubing and wrapped it around a few down tubes on my header. I used small bits of tubeing to go between each pipe so I could prebend the tubing and spiral it on. I would then pump water thru it and into a shower head. I had to play around with the number of wraps to get the temperature right for my showers, but it worked great. I sealed it up with header wrap to contain the heat. Start the motor, let it warm up, start the pump, and take a hot shower. I should work for a heater....

I think it would be easier to use a small oil cooler (motorcycle) and an oil thermostat to get heat from. I have a system sketch I made when I was going down this road. IT can be done with little cost, if you can DIY. I put a SIX in and don't need heat right now.

Just keep the oil lines and cooler out of the cabin and you should be fine. You wont get alot of heat from it if you run 0F air across the coil, but if you duct cabin air to (and through) it you should get some good heat.

Try this.... Duct cabin air (return) from the passenger side long duct to a coil and then back into the cabin (supply) through the driver side long duct. This would help with the "oil" smell and help with maintaining the heat.

You can use OEM air valves or just fab your own. This design should work fine, if you can DIY it into your car.

A couple of thoughts...

1) Cooling the exhaust gas as it flows through the headers/muffler/etc. is bad from the point of view of performance. I'm not sure how much, but seemingly trivial changes to an exhaust system do make noticeable effects. You've got a sweet engine, make sure you don't rob yourself of all the power you've paid for. (Of course, the stock H/Es do cool the exhaust, so the effect prolly isn't so great after all.)

2) I think any kind of tubing wrapped in/around the exhaust system is going to be a headache. If the tubing isn't brazed/welded on, you won't get much heat transfer; if it is, the frequent, huge heat cycles are going to make for serious thermal expansion stress issues. I wouldn't count on it lasting very long.

3) Using hot oil might work, but not nearly as well as water. The specific heat of oil is only half that of water, and I think the viscosity makes a boundary layer that hurts as well. But with a big enough oil cooler and fan, you can prolly get enough heat.

3) Are you handy with upholstry ? How about running a zig-zag pattern of 1/8" tubing through your seats and plumbing it in to the oil circuit. That way no annoying fan noises taint the sweet sweet sounds of your 6.

4) As an alternative, you could move the oil tank into the cabin. Put in in the passenger seat, dresss it up a bit, and you can ride in the carpool lane.

5) If it was me, and I had the money, I'd go with a gas powered heater. I think I read that they were used in 911s in colder (e.g., Scandinavian) markets. Probably the best part is that you get heat right away. I don't know if gasoline odor is an issue, but Summit Racing sells gas fragrace additives with cool choices like grape, cherry, and pina colada.

QUOTE (East coaster @ Nov 9 2005, 06:57 PM)

My setup is a 3.6 with Euro race headers..........

how about those then ...

I would NOT run oil lines in the cabin...Not worth the RISK. HOT oil on skin is not fun..

It may have been done but avoid it. I have heard of some using copper pipe to incase the hose

I'm with Andy on this one. I would even believe that you could get heater boxes, like the ones shown, retrofitted to your current headers. That could be cheaper than the difference between selling yours and buying new w/boxes, if not, do the swap. This assumes that the rest of the stock style system is still there, air ports off of the cooling shroud, etc. This would give you all of the features of the stock climate control system.

Eric

You probably only need one heat exchanger.

My stock 1974 2.0 only has an aux. blower ducted to the driver side. The passenger side was blocked off at the factory (just like all the later cars were). Only the early cars seem to have been fitted with ducting to blow air into the passenger side via a "y" pipe installed on the aux. blower fan.

So in effect, the passenger side exchanger did very little in heating unless it was plumbed up like an early car.

With this in mind, I see no need to run with both exchangers. A box could be fabricated around one of the headers and ducted into one of the stock heater tubes to retain factory style heat/ventilation function.

just my 0.02.

(Or you could just wear a heavier coat)

QUOTE (SLITS @ Nov 10 2005, 07:43 AM)

QUOTE (maf914 @ Nov 10 2005, 07:24 AM) Does anti-freeze affect the boiling point of water?   Duh! Ever read the back of the bottle?

I drive a 914, so why would I even have a bottle of antifreeze, much less read it. Can we say aircooled? Helloooo!

QUOTE (maf914 @ Nov 10 2005, 02:57 PM)

QUOTE (SLITS @ Nov 10 2005, 07:43 AM) QUOTE (maf914 @ Nov 10 2005, 07:24 AM) Does anti-freeze affect the boiling point of water?   Duh! Ever read the back of the bottle? I drive a 914, so why would I even have a bottle of antifreeze, much less read it. Can we say aircooled? Helloooo!

This will be the first winter with a watercooled...for the wife

She's tired of no heat on her 120Km round trip to work.

I'l have the 914, my '67 bug and her '67 bus for summer cars.
Just say no to water.

QUOTE (JOHNMAN @ Nov 10 2005, 10:51 AM)

You probably only need one heat exchanger. My stock 1974 2.0 only has an aux. blower ducted to the driver side.

While the heater blower is only connected to the driver's side, the engine cooling fan is connected to both sides. They both do contribute to the heat.

The 70-72 cars had a centrally-mounted fan with two outlets. 73-74 had the fan on the driver's side with a single outlet; 75-76 had the side-mounted fan with a splitter on the outlet.

The original Sixes (and all 911s up into the 70s at least!) had no heater blower at all. All warm air came from the engine cooling fan and was then pushed into the heat exchangers.

BTW, several very experienced 914-6 conversion people have said that the quality of the currently available aftermarket 914-6 exchangers is less than stellar. I know at least one who has told me that he will only use stock exchangers, or headers--period. No more aftermarket exchangers at all for him.

--DD

QUOTE

BTW, several very experienced 914-6 conversion people have said that the quality of the currently available aftermarket 914-6 exchangers is less than stellar.

I've heard this also...from those who have tried them. I think the gas heater is probably still the best option....had one in an old Corvair once when I lived in Michigan and it really cooked. Anybody know the price range on these?

50/50 antifreeze and water raises the boiling point up to about 250 degrees F.

I think you'll get enough heat, but building and maintaining the system will probably be more of a pain than buying a set of headers with HEs on. You can also sell on your existing headers to help offset the cost. It might even be cheaper.

Fluid systems are hard enough when you have an existing thermostat and water pump and you're just trying to get everything working right. Something like this I think you'd have to do some work to stop it boiling over.

With my Subaru conversion, I could reliably boil my cooling system before it got to temp because one of the coolant hoses went too close to the header/up-pipe - so I'm reasonably sure there is enough heat there. But it did boil the system over. Took me a long while to track the problem down.

How about running an oil cooler on the front grill vent by the dash, and putting the vent box under it or surrounding it for your heat. Add a fan, and some levers to close it, and you have adjustable heat...

That is what im going to do with my sbc.