Simple and cheap DIY exhaust heat to coolant heater idea - using air to transfer heat

[Daox]

That would be great if we could simply do that. The problem arises when the thermostat closes and the coolant starts to boil because the manifold gets up to over 600F. Now you have a pressurized coolant loop and its gotta give somewhere. The 3rd gen Prius gets around this by diverting exhaust flow away from the heat exchanger. I'd rather not have to start hacking into the exhaust.

[pgfpro]

Originally Posted by Daox

Yeah, that would work. But, getting heat doesn't seem to be the problem. One could simply wrap some copper around the exhaust pipe and be done. However, its now dumping a lot of heat into the coolant once up to temperature and the radiator how has to dissipate all that heat. More heat to the radiator means more airflow to it, which means worse aero. There are a lot of ways of disconnecting that heat, but this is the simplest I've been able to come up with.

I see your dilemma. For me I only flow water through the center cartridge during the winter months. Right now the lines are disconnected and run a bi-pass loop around the turbos center cartridge.

During the winter months I will hook it back up and run full grill block with a Lexan adjustable plate for air flow. I also will by pass the inter-cooler all together.

On my engine at idle after a long day of testing my hottest inner exhaust runners only get around 380*F to 420*F. The outside exhaust runners run around 280*F to 325*F. The turbos center cartridge runs around 350*F.
All readings are taking with a infra red gun.

[2000mc]

I probably haven't thought this through enough but...
How about copper tubing, a pump - like http://www.amazon.com/gp/aw/d/B007XH...XN542E2NG370JE but not pressurized, just filled with water. If you turn off the pump on a longer drive, let it boil, then you just fill it up before the next time you expect it to work. Maybe there would be a more elaborate way of having a reservoir which would refill the system with the circulation pump the next time it's turned on, without having the reservior be part of the circulation circuit.
Edit: Maybe position the pump and reservoir as low as possible, so that with the pump off, water would drain back to the reservior, away from the heat exchangers. Sizing the reservior to be running near empty while the pump is on / system circulating

[oil pan 4]

Just use a universal fit turbo waste gate to control exhaust flow to a repurposed diesel EGR cooler.
I think this is how I am going to put an exhaust heat exchanger on my Camaro. Use the EGR passage cast in the cylinder head that is blocked off at the intake manifold. I can tap into it by attaching a turbo waste gate to the intake manifold. Then the rest is only a matter of plumbing.

[Isaac Zackary]

I've been trying to figure out how to do this too. So far all I've done is put on a 1,600W block heater on my little 1.6L VW Golf diesel. But exhaust heat would be great. Especially on -40° days. All my traveling is usually less than 10 minutes.

[oil pan 4]

Here is the original post.
http://ecomodder.com/forum/showthrea...ler-29085.html

Can some one change the name of that post to something more searchable.
Something to the effect of:
"fast warm up ideas: Exhaust heat exchanger"
or
"Exhaust heat recovery heat exchanger"

[Daox]

Originally Posted by 2000mc

I probably haven't thought this through enough but...
How about copper tubing, a pump - like http://www.amazon.com/gp/aw/d/B007XH...XN542E2NG370JE but not pressurized, just filled with water. If you turn off the pump on a longer drive, let it boil, then you just fill it up before the next time you expect it to work. Maybe there would be a more elaborate way of having a reservoir which would refill the system with the circulation pump the next time it's turned on, without having the reservior be part of the circulation circuit.
Edit: Maybe position the pump and reservoir as low as possible, so that with the pump off, water would drain back to the reservior, away from the heat exchangers. Sizing the reservior to be running near empty while the pump is on / system circulating

This is basically the other idea that I've been toying around with in my head. A second second coolant loop with gravity drain back that is open to the atmosphere. I even drew up a quick diagram yesterday before coming up with the air idea. At the moment, I think that this idea would probably be more effective (able to move more heat), but it'll also cost more and is more complex. So, for now I think I'll be pursuing the air idea. I'd encourage someone else to try it though! I'd love to see testing and results.

There are issues to deal with in this scenario, but I'd like to keep this thread about the air idea. Feel free to make another thread on this though as I'd love to discuss and develop the idea.

Here is the diagram I made for it.

[Daox]

Originally Posted by oil pan 4

Just use a universal fit turbo waste gate to control exhaust flow to a repurposed diesel EGR cooler.
I think this is how I am going to put an exhaust heat exchanger on my Camaro. Use the EGR passage cast in the cylinder head that is blocked off at the intake manifold. I can tap into it by attaching a turbo waste gate to the intake manifold. Then the rest is only a matter of plumbing.

That is a great idea. Its just a lot more complex and costly than the air idea. I don't want to stick a turbo on the Metro (though that would make it a lot more fun ). I wanted the setup to be as simple and cheap as possible to make it a viable mod for more ecomodders.

[SDMCF]

Originally Posted by Daox

A second second coolant loop with gravity drain back that is open to the atmosphere.

If the reservoir were insulated it could be used to retain some heat from one session to the next, reducing warm-up times still further. You might need to run the pump for a short time at the end of a trip (perhaps on the last few km of a trip) to get the best out of that configuration.

[Isaac Zackary]

I've thought about using air to heat my Beetle's engine. It has nearly everything I need already built into the engine. There are two exhaust to air heat exchangers on each side of the engine. The engine is air-cooled, so all I'd have to do is route the heated air over the head fins. There is no liquid coolant, other that 5 pints of oil, that is used to cool the engine, so air is about my only medium to heat it.