Grill block is done and has been for a while.
The heater does not have a valve that stops flow through the heater core. It is plumbed into the bypass circuit that moves coolant through the block before the thermostat opens. My volvo, on the other hand, is setup like you suggested so I am familiar with it.
The setup, in theory, should only increase the coolant capacity by a gallon or less. A 1" hose (or thereabouts) that was say 25' long doesn't hold all that much volume. Thus, warm ups that were from dead cold (say I spend the night at a friend's house or something) would be slightly longer.
When I leave from home, the 120v coolant heater will be bringing me near temperature before I get in. When I leave the gig, 2-7 hours after parking the car, the hope is that the wax is still in the process of changing from liquid to solid.
The only time this would be counterproductive would be if I parked for 24 hours or more and didn't use the block heater and the outside temp was less than 50df or so. I don't stay in hotels while on the road. I drive home and just get in very late. I still think this added amount of coolant would be mostly negligible in this instance. But who can be sure without trying it out!
Wax holds a constant temperature during this change. Lots of wax means it can theoretically hold a steady temperature in an insulated vessel for several hours.
The wax doesn't have to become liquid for the car to be warm. The coolant will move around inside the insulated compartment while it's getting warm. Before all of the wax is transformed back to liquid, the engine should make it to operating temperature.
Okay, that all being said, here's the other piece of the puzzle. If you only stored hot coolant, there would only be that much hot coolant available for the next start up. This system would store heat energy in an exchanger. So, the coolant in the compartment on start up would be warm or hot. Cold coolant coming in would absorb some of this energy before it left to head back to the block. Thereby rapidly warming the engine. It's not as though you only have 2 gallons of warm coolant and nothing else (like how the prius works).
Here's a quote from another user, trebuchet03 a while ago:
"Well.... here's something I just thought of - sorta. So I'm in a heat-mass transfer class (I'm a mech engineering student, yay classes!), and I'm studying for finals and one tidbit is heat capacity.
That got me thinking. We want to store a great deal of heat - not necessarily at a high temperature, just a lot of it. The thermal mass of the coolant, head, oil etc. is huge.
One great way to store heat is to take advantage of latent heat | heat of fusion -- which is heat/energy in solid-liquid phase changes. I need to do some research/calculations - but I suspect 3L of wax will hold more heat than 3L of coolant. I think paraffin wax (yes, I know - fire hazard if exposed) does the solid-liquid phase change around 50C. And I'm sure there's other suitable (albeit less accessible/more expensive) materials out there.
What's great about latent heat storage is that there's A LOT of it. And once you begin the phase change, the average temperature stays constant until the change completes. Now I just need to think of a way to implement - probably VIA some sort of "bucket" heat sink/ heat exchanger.
If anyone here subscribes to Autospeed (a great Aussie motor mag online), they actually talked about a theoretical inter cooler that used wax ("Performal") to basically make your IC a bigger heat sink (because after all, that's what it is for the most part). This idea is backwards to theirs :P"
Direct link to this discussion:
http://www.gassavers.org/showthread....heat+exchanger
50dc is 122df. That's not that far from operating temp of 195df. Block heaters don't get all the coolant much hotter than 122 either.
Paraffin's flash point is 390df. No worry of fire, especially since it's in a sealed vessel.
Scrap wax may be hard to come by. I assumed that dyed wax was not re-used as it is hard to get the color/scents out of it. (when making candles)
Shows what I know!
Still, paraffin is relatively cheap.
Anyway, what are everyone's thoughts?
Thanks for the input so far!
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