letterman7
Honorary Admin
Ok... this should probably go into my build journal, but I'll put it here instead since it's a heat related post. I'll let some of the "secrets" out as I got to a stopping point today waiting for the rest of my goodies to arrive.
As some of you know, this car has/had air conditioning installed by the factory. It wasn't good to begin with (old compressor, poor condenser location), and after years of sitting it just wasn't to be. So, plans went forth to yank it out and replace everything. In researching what I wanted to replace it with, it became very apparent that most aftermarket a/c units had a heat option, using the coolant from the engine just like a heater core (well... I guess it is a heater core anyway). That let me to thinking about how I could harness something from the engine to heat coolant.... the obvious was the exhaust system. Instead of hot air being blown in to the cabin, I'd have hot coolant circulating into the core, giving me some measure of control. Now.. how to do that. My first thought was a liquid intercooler - route the exhaust gases though the box and let the coolant draw the heat. But those are usually bulky and not inexpensive. And, where the hell would I put it and still route the exhaust?
Some further investigating and researching on eBay of all places revealed these little beauties:
Those are EGR coolers from a late '90's to early '00 VW diesel Jetta/Beetle. EGR coolers are actually pretty common as I found out for diesels - the Ford and GM ones are huge. These are rather petite - about a foot long and 2 inches across.
You'll notice one end has a flange and one has a pretty severe bend:
Knowing that the bend would be a hell of a restriction for the exhaust gases (these bolted to an extension on the exhaust manifold of the native VW, and were fed coolant through various hoses to the block), I opted to cut it off and open up the end as much as I dared without cutting into the water jacket:
It ain't a pretty cut, but it opened up the tunnel well enough. The other end with the flange I'm leaving for the moment. I'll likely need to cut that off as well, but for the moment I enlarged the opening. Once I get the engine mounted and figure out how much room I have for mufflers I can make that determination.
So.. really, that's the "big" surprise. The coolant hoses will be routed from the EGR coolers to a holding/recycling tank, down through the a/c heater core, to a pump, out to a heater bypass valve which will feed another heater core that's hung in the open to act as a radiator and back again:
Installed on the engine, they don't look too bad. Don't be too harsh on my welding - the header collectors were all hand fabricated so they're a little ugly. The actual downpipes are from a 912E Porsche, the rest of the pipe is off-the-shelf J tubes from CIP1.
And yes, I know the garage is a mess. It's 20° outside and I'm not about to clean it out!
Hopefully this system will work as intended. I might even wrap the header and EGR pipe with some header wrap to keep the heat contained, but I'll cross that road when the car is back together and running. If it does work, this system would be easy enough to make work on a T1 engine using the J pipes off the back exhaust ports as well. It'll take a little welding, but with a little ingenuity I think it can be done!
I guess I should have added that yes, it works on the same principle as Yaughn's link to the oil cooler (which takes up less space, however) using the engine coolant to cool the oil. Here, it's just cooling exhaust... sort of *laugh*
As some of you know, this car has/had air conditioning installed by the factory. It wasn't good to begin with (old compressor, poor condenser location), and after years of sitting it just wasn't to be. So, plans went forth to yank it out and replace everything. In researching what I wanted to replace it with, it became very apparent that most aftermarket a/c units had a heat option, using the coolant from the engine just like a heater core (well... I guess it is a heater core anyway). That let me to thinking about how I could harness something from the engine to heat coolant.... the obvious was the exhaust system. Instead of hot air being blown in to the cabin, I'd have hot coolant circulating into the core, giving me some measure of control. Now.. how to do that. My first thought was a liquid intercooler - route the exhaust gases though the box and let the coolant draw the heat. But those are usually bulky and not inexpensive. And, where the hell would I put it and still route the exhaust?
Some further investigating and researching on eBay of all places revealed these little beauties:
Those are EGR coolers from a late '90's to early '00 VW diesel Jetta/Beetle. EGR coolers are actually pretty common as I found out for diesels - the Ford and GM ones are huge. These are rather petite - about a foot long and 2 inches across.
You'll notice one end has a flange and one has a pretty severe bend:
Knowing that the bend would be a hell of a restriction for the exhaust gases (these bolted to an extension on the exhaust manifold of the native VW, and were fed coolant through various hoses to the block), I opted to cut it off and open up the end as much as I dared without cutting into the water jacket:
It ain't a pretty cut, but it opened up the tunnel well enough. The other end with the flange I'm leaving for the moment. I'll likely need to cut that off as well, but for the moment I enlarged the opening. Once I get the engine mounted and figure out how much room I have for mufflers I can make that determination.
So.. really, that's the "big" surprise. The coolant hoses will be routed from the EGR coolers to a holding/recycling tank, down through the a/c heater core, to a pump, out to a heater bypass valve which will feed another heater core that's hung in the open to act as a radiator and back again:
Installed on the engine, they don't look too bad. Don't be too harsh on my welding - the header collectors were all hand fabricated so they're a little ugly. The actual downpipes are from a 912E Porsche, the rest of the pipe is off-the-shelf J tubes from CIP1.
And yes, I know the garage is a mess. It's 20° outside and I'm not about to clean it out!
Hopefully this system will work as intended. I might even wrap the header and EGR pipe with some header wrap to keep the heat contained, but I'll cross that road when the car is back together and running. If it does work, this system would be easy enough to make work on a T1 engine using the J pipes off the back exhaust ports as well. It'll take a little welding, but with a little ingenuity I think it can be done!
I guess I should have added that yes, it works on the same principle as Yaughn's link to the oil cooler (which takes up less space, however) using the engine coolant to cool the oil. Here, it's just cooling exhaust... sort of *laugh*
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