had an idea , what i call the 'stroke warmer.

Picture a piece of 3/4" copper pipe entering the exhaust system immediately before the EBPV, and then returning immidiately after the EBPV. This pipe would be about 6' long and be bent to fit underneath the truck.
A second pipe (1-1/4") would be overtop of the origianl pipe, with the coolant line spliced into it.

When the EBPV closes, the hot exhaust would flow through the pipe, warming up the coolant.

When the EBPV opens, zero effect.


What do you guys think of this?

 

Why would you want too ??

 

Instead of working the engine hard to warm up, the hot exhaust heats the coolant, giving almost instant cab heat, and warms the block.

 

The energy conservation concept is solid, but before you do that, there needs to be a lot of very careful engineering work done on the thermodynamics, in addition to a lot of thought about the potential impact of system failure (read as "leaks").

The exhaust temps are much higher than you ever want your coolant to get to, and when you place that much heat on a liquid line, you have to be very careful to not create flashing (boiling) inside the liquid line or you will get scale buildup/pluggage and may overpressurize part of the liquid system. Best approach would be a small diameter exhaust line (1/2 inch) with a large diameter liquid line (1-inch to 1-1/2 inch) so that you would have a large heatsink to take in the radiant heat from the exhaust line.

Next issue is materials of construction. By using copper, you're going to get galvanic corrosion due to the disimilarity of metals. I would use simple carbon steel pipe from Home Depot (sometimes called "black iron") for the exhaust and then you could use copper for the liquid, though I would seriously consider getting a stick of stainless tubing. Then, you need to not let the two pipes come in direct contact with each other or you will once again create galvanic corrosion potential.

Finally, if you could find a good spacer material to keep the two pipes close together but not touching (something that would both tolerate the heat and not be metallic), you could warp the entire "heat exchanger" in some insulation wrap end further increase the thermal efficiency.

One other consideration... I would consider using a solenoid valve that was operated thermally so that when the engine is cold, you get the coolant flow through the line, otherwise, the valve should probably stay shut so that you don't create too much heat buildup in the coolant system when everything is otherwise running at design temps.

Overall, though the concept has merit, I would simply stick with the engine block heater that runs on a timer. Sometimes, "simpler is better" and "less is more".

 

"Best approach would be a small diameter exhaust line (1/2 inch) with a large diameter liquid line (1-inch to 1-1/2 inch) so that you would have a large heatsink to take in the radiant heat from the exhaust line. "

Thats what i meant.

About the coolant overheating, Thats why the EBPV would be between the inlet and outlet.
Once the EBPV opened, no exhaust would travel through the "heater"

Yes, insulation is a good idea, i thought of "pipe wrap" foam insulation...

A longer pipe would probable give even more heat, but reduce coolant flow to the cab...

Block heater is good, but the truck still needs to warm up...

I imagine very little hot gas would flow through the "stroke warmer" with the ebpv open, however, instead of installing a solenoid valve, I think 10" of pipe away from the exhaust pipe could be just the inner pipe, keeping the coolant portion of the outer pipe away from the exhaust temps...

 

So you're really taking "pipe in pipe", then? From what you wrote, it sounded more like two pipes side-by-side. If you go with the "pipe-in-pipe" approach, you have some real potential issues with any future leak.

I can just imagine the potential effect of a "quench spray" into your exhaust system.

 

If i found some stainless steel pipe, and welded the whole *******, there wouldnt be any leaks....

I thought i could make the whole thing out of copper pipe and solder, but that might be a little on the weak side...


Why would pipe-in-pipe be bad? If theres ever a leak, the coolant would be leaking from the tailpipe...

Pipe in pipe will give more surface contact than side by side.

I'll bet some WVO burning guys (wish i was 1 of them) are liking this idea right about now...