Had an idea for supplemental heat this winter for my 03 2500 Ram HO 5.9 and after running a google search on portable water heaters... I noticed Coleman markets a unit for heating water on demand upto 160F (depending on ambient temps of course). The inspiration driving this experiment (besides having access to free propane) is to duplicate the effects of other aftermarket supplemental heating units (i.e. Webasto) but at a fraction of the cost...by beefing up the Coleman unit (where needed) to handle the job.

The benefits of course would result in faster cabin heating and more efficient cold weather starting when its impossible to plug in the block heater. Incidentally, I believe a remote on/off switch could be added to shut the unit down once the coolant reaches operating temp. - Only one important question remains...by tying the Coleman water heater into my Rams cooling system, would 120-160F water risk cracking the block?

Thoughts anyone?

http://www.coleman.com/coleman/colem...ategoryid=2200

 

Lots of "why?"s here, but I'll just ask one:

why do you think 160*F water would crack an engine block that routinely sees coolant temperatures ranging from subzero to well over the boiling point?

 

there are a few companies that do the same thing but burn diesel fuel....so you don't have to carry propane....

but the propane for supplemental heat just gives you a reason to inject it...

 

The other reason I'm pursuing supplemental heat is purely out of necessity... ever since I've converted my rig to run on veg I've been interested in the quickest possible switch-over times durring the winter...the benefit of getting cabin heat asap on 10F days is simply icing on the cake. Also, those pre-heat units which tap into the Diesel line are sweet. Webasto out of Germany makes a great unit which can be remotely activated. I just can't justify shelling out $2000+ on a pre-heater which gets 4 months of use vs. designing something from items off the shelf at a fraction of the cost.

As for cracking the engine block, I grew up listening to my grandfather and father (both ran a small auto repair shop back in the day) telling me to never supply hot water to a cold engine, nor cold water to a hot engine as severe temperature changes could crack the block...so in dreaming up this experiment I'm error-ing on the side of caution vs. turning my 5.9L Cummins into the worlds biggest and costliest paper weight

As for propane...unfortunately I don't have free access to bulk propane, only the disposable bottles used in camping equipment. I've considered propane injection but nothing beats the cost savings you get when running veg.

 

You're going to be heating up the water while circulating it right?? That should be no different than the engine heating up by itself. Just like the Webasto. It shouldn't hurt the block at all.

Randy

 

Yes, I do intend to circulate the water when the unit is operational. Ideally, I want see if the unit can function as a pre-heater on really cold days 30min prior to starting. Ultimately, I'd like to integrate a wireless remote to turn the unit on/off from a distance...possibly with the aid of an aftermarket car alarm kit(?)

 

Your scheme won't be able to produce delta T quickly enough to present thermal shock, so no worries there!

 

I would be more concerned about if the coleman unit could handle the pressure from the cooling system when your operating the truck... I wouldn't think your going to have a realibility issue on the motor side as much as you will have on the heater side... What happens when the water temp circulating throught the coleman is at 200 degrees @ 10 PSI...

 

save your money, buy the wabasto, it works great and you can transfer it to the new truck if you want, i have one in both my trucks and will NEVER go without one again. jumping in your truck first thing in the morning with snow all around it and the guy beside you is out there scraping off his windshield and yours is steaming away is priceless.

 

Yeah was wondering the same thing. Regardless, I found a used coleman on ebay and will have to see how well the units designed when it arrives. I skimmed the specs and instructions at coleman.com and it looks to be built well beneath the fancy plastic housing. unfortunately, I couldn't locate max operating pressure but noticed the unit comes with an optional garden hose adapter which tells me its likely been designed to handle at least 20-30+ psi since most household appliances require such pressure to operate properly. Actually, I wouldn't be surprised if it could handle slightly higher psi's since many municipal water supplies operate between 50 and 100 psi. If the unit does leak I'll try fabricating new seals from heavy duty rubber impregnated cork...if the cork fails I'll bring in the permatex Another nice feature which plays into my favor (aside from the unit conveniently operating on 12 volts) the heater apparently cycles off at 160F and won't cycle back on until it senses 120F water, which should help eliminate any over heating issues. The biggest challenges I foresee: 1) Keeping the propane cylinder from freezing when the Colemans' running on high. 2) Keeping the propane cylinder safe under the hood

 

In my feeble little brain I'm thinking, why not just cut a heater line and install something like a flat face hydraulic coupler. They come in a set with a male and female. You'd need two sets.

 

Was thinking the exact same thing however I was concerned the hydraulic couplers would act as heat sinks and dissipate too much heat away from the coleman. Also concerned the couplers would restrict flow, leak or allow air into the cooling system over time(?) I think the best way to approach this is to keep it simple and refine it further after its proven to work.