12v Block heater?

[BioHazard]

I'm putting together a 12v gas driven "APU" for my pickup truck, ('73 chevy) that I hope to be able to hide under the hood. (there's a lot of space in this old square body) I'm converting all of the engine's belt driven accessories to 12v electric - fan, water pump, power steering, and even A/C.

What I'm having trouble finding is a 12v block heater for the winter. I already have a 120v block heater, even though I don't live in a very cold climate. This allows me to start the old carbureted 350 without stomping on the gas first. No need for "high idle".

I'd like to find a relatively high wattage block heater (~600+ watts) that will run off the 12v APU, that way I can have heat without the engine running.

Does anybody know where I can find such a thing? The best I've been able to find is a 120 watt pad heater.

[LowGear]

600 Watts / 12 Volts = 50 Amps  I'm curious how many Amps a starter motor pulls for this unit?

I watch motorweek on PBS and it seems to me this is where the newest super duper units are going?

Oh, your question about where to locate one - I don't know.  What would happen if you put 12 Volts across a 120 AC one?  Two in series?

Casey

[Thob]

...
  What would happen if you put 12 Volts across a 120 AC one?  Two in series?

Casey

1/10 the voltage will give you 1/10 the amps, which is 1/100 the power.  So a 600 watt 120VAC heater element driven at 12V will generate 6 watts of heat.

Is there any way to use waste heat from the APU to heat the block on the main engine?  Such as circulate coolant from the APU thru the block?

Air cooled airplane engines used to be warmed by using exhaust heat from a car engine.  Could you route the APU exhaust around the block?

[Ronmar]

Do you need to keep it warm, or just warm it up prior to a startup?  Perhaps a small remote startable propane heating device?

[TimSR2]

Can't you harvest some waste heat from the apu to do the same job? All you need is a tiny circulator pump hardwired to the apu's alternator and a coil of tubing around the head or exhaust.   Plug it in to your heater hoses.

[highwater]

try searching for stock tank heaters dc.
The off grid/wind guys use them.

Here's a place in Kansas where I've bought some stuff.
Scroll down just a bit.

http://www.kansaswindpower.net/dc_accessories.htm

Might also try the tractor/ranch supply houses.

Randall

[BioHazard]

Do you need to keep it warm, or just warm it up prior to a startup?  Perhaps a small remote startable propane heating device?

I've seen those, but they're big money and all they generate is heat. I'm trying to fit a B&S electric start engine under the hood, basically this will warm the main engine before starts and also allow me to have heating when the truck is off. There are also all sorts of things I want to do with the electricity....

try searching for stock tank heaters dc.
The off grid/wind guys use them.

Here's a place in Kansas where I've bought some stuff.
Scroll down just a bit.

http://www.kansaswindpower.net/dc_accessories.htm

Might also try the tractor/ranch supply houses.

Randall

I like that heating element, can be wired for 58 amps at 14v.

Can't you harvest some waste heat from the apu to do the same job? All you need is a tiny circulator pump hardwired to the apu's alternator and a coil of tubing around the head or exhaust.   Plug it in to your heater hoses.

Know any sources for a small water pump that can handle hot water and doesn't cost a million bucks? One problem I have thought about this is that in the summer, when I don't want the heat, what's the heat exchanger going to be doing?

[DanG]

Modine and Bergstom make truck and bus heating booster pumps in 12 & 24V that come up used and surplus often..

[mobile_bob]

bosch makes an auxiliary heater pump too, they are common on mercedes, some vw, audi's and german cars
they have 5/8 heater hose barbs, and work off of 12volts

they are common as dirt, moderate price for new units, and cheap used.

i pulled 3 of them from the pik a part yard before i left tacoma for 5 bucks each.

nice little pumps

if you need more flow, then DanG has it right!

bob g

[BruceM]

BobG sure knows his diesels.  The MB 77-95 auxiliary water pump is available new for about $95. I'll bet it can be found elsewhere for much cheaper, and used, for peanuts.  They seem to hold up a long, long time.

http://www.ecklersmbzparts.com/mercedes-auxiliary-water-pumps-1977-1995.html

[BioHazard]

I like that little pump! Anybody care to guess how many BTU I could capture from the exhaust of a 6.5hp gas engine?

I watch motorweek on PBS and it seems to me this is where the newest super duper units are going?

You mean APUs on regular pickup trucks? That would be interesting to see...

[LowGear]

You mean APUs on regular pickup trucks? That would be interesting to see...

Yeah, I thought it was goofy too but some of my projects don't pass that test either.  Didn't this thread start out about electrifying all the operations that are normally carried by a fan belt as well?  Oh, the first sentence.

I'm putting together a 12v gas driven "APU" for my pickup truck, ('73 chevy) that I hope to be able to hide under the hood. (there's a lot of space in this old square body) I'm converting all of the engine's belt driven accessories to 12v electric - fan, water pump, power steering, and even A/C.

Some new cars even have an APU - so to speak - to charge the batteries on extended trips.  I think the Volt uses this concept.  Just think of the V-belt savings. 

How about using one of those APUs found on semi's?  We'll sell it to the fleets that spend a lot of time idling like the Police.

Cheers,