[Lord Nelson]

Hi people,

I have bought a Beetle with an aftermarket sports exhaust & manifold etc...the result being that it no longer has the heat exchanges required to warm the car up / de-mist the windscreen etc.

does anyone know of anyway i can install a different system to do the same job....there was a piddly 12v heater wired tot he battery and screwed to the underside of the dash but id rather not.

any help or past experience would be greatly apreciated...

:bandit:

 

[billybug]

Petrol heater like an Eberspacher

 

[Lord Nelson]

Yeah cheers for that...i have jsut looked them up and they are a bit expensive to be fair....lol. on a tight budget.

any other advice?

 

[dub_crazee]

wear gloves

 

[the missus]

as long as the channels arent shagged best bet would be to put heat exchangers on, should fit with the sports exhaust

alternativley, gloves, hat, scarf and be prepared to scrape ice from the inside in winter

 

[Bada Ben]

I've been toying with the idea to fabricate some replica Non-Fresh-Air type heater boxes, to give me some heat. Heat exhangers replaced by Stainless 1 5/8" J tubes into merged header. It always seems like a good idea when it's freezing, but when the weather is good enough to be outside doing those things, I'd rather be driving it. Now on 3rd year of wearing gloves :crazy:

 

[jimcub]

there ia some one I know who has stainless J tubes with stainless boxes welded to them, he bought the engine like that and now plans to set up a pump to circulate water throught them and a heater matrix, so he can blow hot air on to his screen.

 

[Mr.Whippy]

I'm working on the idea of a water cooled heat exchanger pumping to a heater matrix / blower under the back seat opposite the battery that will blow into the heater channels.

Still very much in the design stage but there was somebody posting on here a couple of years back who said he'd done it and had good results.

Don't hold your breath though - At my current rate of progress I'll be lucky if it's on the road in 12 months from now.

Any electrically powered heater will be next to useless, unless you have a 13 amp 240V mains supply inside the car.:lol:

Dave.

 

[jimcub]

Mr Whippy use an inverter, some one once used a hair drier from one. May need 3 hands to drive like that.

 

[evilC]

there ia some one I know who has stainless J tubes with stainless boxes welded to them, he bought the engine like that and now plans to set up a pump to circulate water throught them and a heater matrix, so he can blow hot air on to his screen.

Stainless is a bad medium for that application as it is not good at heat transfer but the principle sounds fine.

But I've just thought that a better alternative would be to have a water/oil cooler with a standard radiator to cool the water and a diverter to power a traditional heater. You could probably get away with a small rad - classic Mini? with an electric fan in the space above the transmission.

evilC

 

[Mr.Whippy]

In winter it takes a fair while for the oil to get warm, and unless you have a long journey (motorways) you wouldn't be able to switch the oil heated heater on for quite some time.

I have a 3 mile journey to work, on the coldest days my oil temp hasn't even moved off the 50 deg C mark by the time I get to work.

I'm going to explore the water cooled exchanger route.

Even with a 12V inverter, you're going to struggle getting 2KW to run a mains fan heater, and you'd probably flatten the battery pretty quickly as the alternator would struggle to replace that sort of power, unless you only ran it for short periods of time.

To heat electrically in winter (decent heat) you need a long extension lead.

Dave.

 

[evilC]

Dave,

I wouldn't expect a water cooled car to get up to more than 50 degC on a very cold day in 3 miles! I appreciate that the oil may take a little longer to heat a water/oil exchanger but all the kit is available off the shelf and it gives the opportunity to use standard aftermarket exhaust bits like 'J' tubes etc

Problems associated with water cooled exhausts are:
1) Potential failure of the exhaust pipe and the ingestion of water into the engine.
2) Cooling the exhaust gases reduces power (on two cylinders)
3) The water cooled exhaust is in a vulnerable place under the car.

evilC

 

[Trikky2]

The complex and difficult solutions people come up with just to not fit heat exchangers :lol:

ps. a 2kw fan at 12 volts will pull 166 amps :lol:

 

[Mr.Whippy]

Valid points, but -

Water ingestion into the engine is a potential problem with all W/C engines, probably much more so due to head gaskets etc. I would expect water vapour to be blown out of the tailpipe in any case if it were to fail.

Exhaust gas cooling will down the performance slightly, but then you have exactly the same problem with normal heat exchangers.
In winter daily driving, it's pretty unlikely you'll be wanting to use every last HP available (beetle with 2L plus in my case)
Plus, if it's a stainless system, you can drain the coolant in summer, so that doesn't have to be a problem.
Somebody on here (a couple of years ago) posted up that he got toastie warm car heat using only 1 W/C stainless exchanger, though we'll have to see about that. I intend to try this experiment, but it will be 12 months or more before the car sees the road, so don't hold your breath. I will fully document it online when I do it though, so the results will be available.

Water cooled heat exchanger is vunerable, yes. Less so than standard heat exchangers though, as I intend to make the outer pipe not too much larger than the inner exhaust pipe, to reduce coolant volume and speed up warm up time. My car isn't a weedhugger, and I run a towbar that doubles as a sump guard. The associated pipes, valves and pump will make a more complex system, and hence more fault liability but it's only a heater and the worst that could happen is that you will have a cold car until you can fix it. It will certainly be a darn sight less complex than an eberspacher.

Would also be intresting to try it with a water cooled oil cooler, but I think there's a lot more heat available to be extracted via one of the exhaust pipes, and it will heat a lot sooner, which is when you need the heat on a cold morning, - ASAP.

Practical testing is the way forward IMHO.

There's 3 reasons I don't want to fit regular heat exchangers.
1 - They're too restrictive for a big motor and the "big bore" ones don't have proper fins, so they don't heat very well.
2 - I want to use the extra air that would normally go to the heaters, to help cool the big engine.
3 - I'm a born tinkerer and can't afford a castle in Transylvania yet. VW body parts are readily available though, Igor.

Dave.

 

[donwaldo]

I'v just had a brain wave, why not make a couple of holes in the cooling fan cover, then attach them to two pipes (you could probably get some of that flexible aluminium stuff) going down under the engine. It you then put some fins on to exhaust pipes for cylinders 1 and 3 and put metal jackets round them, the air from the fan will then blow along inside the jacket and get hot !!! ... that could then be directed (with another couple of bits of flexi pipe) through a couple of holes under the back seat ....and 'hey presto!' hot air in your beetle,... in fact with a bit more ingenuety ( and a few more pipes you could even get it to demist the front windscreen !)..... sometimes I amaze myself with my inventive mind, feel free to use this idea if you want guys

 

[Bada Ben]

I'v just had a brain wave, why not make a couple of holes in the cooling fan cover, then attach them to two pipes (you could probably get some of that flexible aluminium stuff) going down under the engine. It you then put some fins on to exhaust pipes for cylinders 1 and 3 and put metal jackets round them, the air from the fan will then blow along inside the jacket and get hot !!! ... that could then be directed (with another couple of bits of flexi pipe) through a couple of holes under the back seat ....and 'hey presto!' hot air in your beetle,... in fact with a bit more ingenuety ( and a few more pipes you could even get it to demist the front windscreen !)..... sometimes I amaze myself with my inventive mind, feel free to use this idea if you want guys

It'll never work :crazy:

 

[Trikky2]

Interesting idea. Thinking about it though, a couple of points do spring to mind.

Plus, if it's a stainless system, you can drain the coolant in summer, so that doesn't have to be a problem.

You will have to because the water will boil. The exhaust gets considerably hotter than 100C.

This could also be a problem when running the system to provide a little bit of heat whilst on a motorway for instance. Not many drivers have their heaters on flat out all the time. Often the heater may be used in the morning but not in the afternoon.

Would also be intresting to try it with a water cooled oil cooler,

Ideally, for it work at its best, the oil in the engine should be hot, 90 is a good figure for instance. Over cooling the oil is not ideal and its why a correctly fitted extra external oil cooler will have a thermostatic bypass valve.

- I want to use the extra air that would normally go to the heaters, to help cool the big engine.

When you need the cooling ie. when the weather is hot, you dont use the heating - thats the way the original VW system was designed.

- I'm a born tinkerer and can't afford a castle in Transylvania yet. VW body parts are readily available though, Igor.

Like it :lol: :lol:

 

[evilC]

Interesting idea. Thinking about it though, a couple of points do spring to mind.

You will have to because the water will boil. The exhaust gets considerably hotter than 100C.

This could also be a problem when running the system to provide a little bit of heat whilst on a motorway for instance. Not many drivers have their heaters on flat out all the time. Often the heater may be used in the morning but not in the afternoon.

Ideally, for it work at its best, the oil in the engine should be hot, 90 is a good figure for instance. Over cooling the oil is not ideal and its why a correctly fitted extra external oil cooler will have a thermostatic bypass valve.

When you need the cooling ie. when the weather is hot, you dont use the heating - thats the way the original VW system was designed.

Like it :lol: :lol:

the whole thing will work along the lines of a standard water cooled car i.e. the heat is dissipated through a radiator (with or without fans - depending on location) when the excess heat is not required. Obviously that whole system will require thermostats as normal to monitor and divert the water and oil supplies, thus not overcooling the oil and providing unwanted heat to the cabin.
Forgive me if I am wrong but a standard water cooled car generally operates at about 80 degC with the oil temp at around 90 - 100 degC so the oil should be a hotter heat source.
evilC

 

[Mr.Whippy]

You will have to because the water will boil. The exhaust gets considerably hotter than 100C.

This could also be a problem when running the system to provide a little bit of heat whilst on a motorway for instance. Not many drivers have their heaters on flat out all the time. Often the heater may be used in the morning but not in the afternoon.

I'll have to see how it goes on that point. If the exchanger area is too large compared to the heater matrix then it's possible it would boil over on a long hot motorway run in the middle of summer. The trick will be making it boil proof even in the worst situations, then draining down in summer won't be necessary. Using a pressurised system will increase the boiling point of the coolant and will help somewhat. Experiments will either make or break the idea.

As i see it, there's two ways round the situation of heat control.
1 - Having a single heater matrix inside the car, with the fan blowing all the time, and some way to duct the spare heat outside the car when it isn't required.

2 - Have 2 heater matrix's, one inside and one outside the car. Use a valve connected to the heater control cables to direct the hot water where required.

I plan to go with method 2.

When you need the cooling ie. when the weather is hot, you dont use the heating - thats the way the original VW system was designed.

The air blows from the fan housing through the heat exchangers regardless of whether the flaps are open or closed. But that's a whole different kettle of fish.

Dave.

 

[Trikky2]

the whole thing will work along the lines of a standard water cooled car i.e. the heat is dissipated through a radiator (with or without fans - depending on location) when the excess heat is not required. Obviously that whole system will require thermostats as normal to monitor and divert the water and oil supplies, thus not overcooling the oil and providing unwanted heat to the cabin.
Forgive me if I am wrong but a standard water cooled car generally operates at about 80 degC with the oil temp at around 90 - 100 degC so the oil should be a hotter heat source.
evilC

So now your talking about a heater matrix to heat the car and a radiator to stop the water boiling in the system and a thermostat to control the two, plus a control valve to allow you to set the temperature in the vehicle, an electric fan to blow the air not to mention the construction of the exchanger itself and all the associated plumbing.

It could be done yes. But to claim its a less complex way of doing it than an Eberschpasser or a propex heater is frankly ludicrous. :lol:

As for using the oil to heat, yes that too could be done and would be equally complex but as has already been pointed out by previos posters, in the winter - when you need the most heat - the oil in an aircooled does not get hot. It will struggle to get above 50C. If you dont believe it then fit a guage and pootle about in winter temperatures for an hour or two.