On Board Water?

I just learned the hard way on the pump side- get a pump that will prime itself and can run dry. An "on demand" type that cuts off when under pressure (when you turn the shower head off or accidentally stop the flow) will also prevent you from having problems. I imagine many bad reviews arise from having the wrong pump for the situation. Mine does not self prime as I thought and runs full pressure when blocked and I know I'll burn it out sooner because of this.

Heater hose should work you're really only working with fluid below 10 psi as I discovered using a 5 psi check valve... So heat rating is much more important as is diameter to keep an unimpeded flow to your engine.

 

FWIW this is the pump I used. Selfprime from 9 vertical feet (3 feet more than the shurflo), run dry, no pulsating when closing my flow control valve on showerhead. It came with all the fittings needed and a strainer and has functioned flawlessly.



Edit: on second though, I think I bought the strainer seperate... cant remember for sure tho.

 

So I'm getting ready to run my own hot water setup on my truck (2014, though my profile is old). I have a 10 plate heat exchange element and plan on recirculating water. I'll use the outlet heater hose for the heat but I'm puzzling out the right spot to mount my heat exchange. The clear space on the back left (looking into the engine compartment) is open enough for the exchanger but will it be fine to run the heater outlet hose to there and back? I'll only have everything connected when I head out camping otherwise it'll be back to stock setup.

Otherwise, I have a shurflo pump for the water side which is plenty strong and self primes.

 

Thanks. I'm going to get the same one Tweeek has. $56 from Amazon, excellent reviews as well. It has all the features you mentioned.

Thanks! Appreciate your post. That's the one I've been eyeballing. I'll get it.

Just curious, but you plan on adjusting the heater hose/ coolant for each trip? Or is this a one time event?

I don't think you'll have an issue with that space and length of the lines.

 

Sounds good to me. My only concern is stressing the engine water pump with the added distance (maybe 4ft). If it isn't a big deal I'll just install the system in a good spot and leave it.

 

No sweat

 

This is why I made my bypass manifold about three inches from the end of one of the heater core hoses I intercepted- when my 3 way valve is set to bypass, the only added stress on the engine is about 12" of 5\8" hose. Turn the ball valve the other way and it then goes through 4-6 extra feet of hose to heat the water. Personally I worry about stressing the engine components by running the water through that much hose all the time (though many have done this with zero issue)

But my truck is a '13 and engines get a little pricey.

 

Where did you get your 3-port diversion valve?

 

I spent more time looking into how the water pump works on our trucks. I wanted to better understand a system I was about to tap into. The more I learn about it, the better I feel about splicing in the heat exchanger.

The DIY water pump replacement thread has some nice pictures of what the pump looks like.

Here is a picture of the pump, it bolts into the engine block, and the flange at the top of the picture bolts to the bottom section of the upper assembly (second picture). A brand new OEM Aisin WPT-802 Engine Water Pump can be had from

$116 AISIN WPT-802 New Engine Water Pump with Gaskets - Compatible with Select Toyota 4Runner, FJ Cruiser, Tacoma, Tundra

Amazon for $92.

The pump connects to the upper assembly, which has (2) large fittings for the radiator, and (2) fittings for the engine oil cooler, AND (5) bypass fittings for coolant. Of the 5 bypass fittings, (2) are for the throttle body, and (2) small fittings for I don't know what, and a larger fitting which I suspect goes to the heater core input, but I'm not sure. And I can't figure out where the heater core return goes to. I need to schedule some time to trace out the heater core hoses...

Here is a picture of the water pump UPPER assembly from the DIY Supercharger install thread

 

Subd to find this later

 

McMaster Carr. I'll dig up my part number later but they'll have the parts you need that wont fail you. I refuse to risk important parts on home Cheapo I've had too many things fail from yhere

 

I think this is the valve you used.

I ordered

$70 Apollo 70-600 Series Bronze Ball Valve, Two Piece, 3-Port Diverting, Lever, 3/4" NPT Female

this one today from Amazon Prime so I'll be able to get everything working after it arrives.

 

Fixed this quote, thanks Crom!

"The more plates and more width the heat exchanger has, the less pressure loss to the fluids flowing through it" -Source

Page 3

 

A question I have on the Thermostatic mixing valve is this.

If one is rated from 120 - 70 and another is rated at 190 - 70. does that mean that at 120, it is going to lock off or damage the unit?

 

Doubt it. The 120 would be the output temp, which is more than warm enough, but the spec you really need to know to avoid damage is your max inlet temp. It needs to be 180+. Though I doubt the water coming through the exchanger is atually getting that hot. The exchanger wont be 100% efficient, so there is probably some wiggle room there.

 

This.

Many have a max inlet temp of 180 which should work great due to the inefficiency of heater hoses, heat exchange etc. Any lower and you risk locking it down on a hot day with a hot engine.
I can say that I hooked mine up to only the hot side and it shut off the flow completely until I attached a hose to the cold side to cool it off & once I did, it worked fine with no damage meaning the heat exchange output doesn't produce above 180

 

Ok. That makes sense.

 

I see that a

$136 Moen 104465 Adjustable Temperature Thermostatic Mixing Valve

Moen thermostatic mixing valve is being offered by Amazon now. I have also found that the mixing valves which offer the

$150 Honeywell Braukmann Sparco AM101-US-1 Sparco Thermostatic Mixing Valve, 3/4' Union-Sweat 100-145F

higher output ratings (100* - 145*F) are more difficult to find. I've read a number of reviews on Amazon about the Honeywell ones with the lower rating (100*-120*F) and there are complaints that when dialed into the hottest setting they don't output water temp at the stated upper range, even when the source is plenty hot, the end result is water that's not hot enough... (I know this is not an issue for individuals using the output of the valve as an input for a truck mounted shower )

On another note, I ordered my pump (Flojet 03526 144A), strainer, and a few fittings. It appears that flowjet utilizes a quick-connect system for attaching fittings to the pump. They call them 'quad port' fittings.

This fitting allows you use a garden hose for an input or output to the pump:


1/2" barb to quad port fitting:



Sample image of a quad port with 1/2" fitting and 90* bend.



What I also like is that the pump is serviceable, the pressure switch can be swapped out, if I ever wanted to go from 50psi to 25psi, simple part on top of the pump. The pump specs document was helpful when looking for accessories and parts.

 

Crom I've got the cheap powers valve and it gave pretty warm output with zero adjustment. I'll get back home this weekend & turn it up to see what i can get out of it. Might put a thermometer in it for good measure.

I think you oughtta go with skygear's deal. The Moen and Honeywell aren't cheap and it looks like the whole shower system were designing operates well below \ within the range of even the cheapest valve.

 

Oh yeah! Time to play with some water! Oh yeah!