Geo Metro Block Heater How-to

[MetroMPG]

Current is circulated only by convection. There's no mechanical pump in these.

[Peter B]

bbjsw10: hey, can you clarify something about your installation of that Kat's heater on your Geo? (Can't tell from the photos). Do you have the Kat's heater set up so that the heated coolant from the heater is first being directed into the heater core in the passenger compartment and from there travelling to the engine block (and back to the Kat's)? Or do you have it arranged so the heated coolant is first being directed into the engine block (and from there into the heater core in the passenger compartment)? I have to choose between these two configurations and can't decide which would be best.

I bought 6 feet of heater hose today and am finally ready to install my own Kat's heater on my ride ('90 Acura). I'm going to tap into one of the heater hoses. I had considered employing the engine block drain plug in my install, before I realised it's buried beneath the exhaust manifold and pretty much inaccessible. I also rejected the idea of tapping into the lower radiator hose.

Thanks for any info.

[bbjsw10]

Peter B, I have it going through heater core first then to block. I am going to be changing this though once my "Tee" shows up at the parts store. I will be tapping into lower radiator hose then tapping into heater core hose directing toward block first. I feel right now I may be losing some of the potential of this heater out my core. I want my block to heat first.

[bhazard]

So whats the difference between the aluminum tank heaters (Amazon.com: Kats 13150 1500 Watt Aluminum Circulating Tank Heater: Automotive)

and the red ones? (Amazon.com: Kats 12080 850 Watt External Tank Heater: Automotive)

just looks?

I think Im gonna buy that 1500 watt aluminum one though. Its only a few bucks more than a lower wattage one. I should be able to run it for less time, and its thermostatically controlled too I believe. Any reason why I shouldnt go for a 1500 watt unit?

Edit: unless I wanted to try rigging up my 750w inverter to a say, 500w heater so I could run out to the car on my last break at work (anywhere from 2-4 hours before Im out of work) to start it on a timer to run for the last half hour or so before I get out of work. But then who knows how long my battery would last. Its a new napa battery if that means anything.

[Formula413]

Originally Posted by bhazard

Edit: unless I wanted to try rigging up my 750w inverter to a say, 500w heater so I could run out to the car on my last break at work (anywhere from 2-4 hours before Im out of work) to start it on a timer to run for the last half hour or so before I get out of work. But then who knows how long my battery would last. Its a new napa battery if that means anything.

I wouldn't do that. Your headlights can kill your battery and they only draw about 100 watts. Maybe if you had a deep cycle battery you could get away with it.

Actually I had a similar idea though. I was wondering if it would actually be feasible to run one of these while the car is running. On bitter cold days my car never actually reaches normal operating temperature unless I am on the highway for an extended period. And any attempt to use the heat just makes it worse. I've blocked off most of my grill openings and that helps, but it would be nice to be able to give the heat an extra boost.

[TestDrive]

Originally Posted by bbjsw10

Peter B, I have it going through heater core first then to block. I am going to be changing this though once my "Tee" shows up at the parts store. I will be tapping into lower radiator hose then tapping into heater core hose directing toward block first. I feel right now I may be losing some of the potential of this heater out my core. I want my block to heat first.

Not sure that will work so well. Won't there be a restriction in the flow when you first turn it on? Coolant/engine cold - so thermostat closed - so coolant can't flow from upper radiator hose through radiator into lower hose - coolant must be pulled bassackward through water pump???

[Peter B]

bbjsw10: What store did you order that "T" fitting through?? I may go the same route.

All this talk about keeping the engine warm in cold weather reminds me of something my father had hooked up to his car ('65 Plymouth Barracuda) to keep the engine warm enough to start during the brutally cold winters we had back in the 1970s. He worked at the Sperry Univac plant in Rosemount, and all the employees had to park their cars outside in a huge lot. Remember, this was back in the days when cars often didn't start in really cold weather.

He read about a device in Popular Mechanics magazine that would cycle the car's engine on and off without anyone in the vehicle. Not wanting to spend money on the plans, and being a techie, he built the device based on the description in the magazine. Not sure exactly how it worked, but it did not have an electronic brain at all. Just a bunch of sensors and solenoids and transistors and timers, etc. I know there was a temp sensor in the exhaust manifold. When the manifold temp dropped below a certain level, the starter would crank and the car would start up and run for X minutes and then shut itself off. It even employed a vacuum sensor so that if the car didn't start after X seconds of cranking, the starter would stop cranking for X seconds before trying again. All in all, a pretty clever set up. He called it "Maynard's Magic Motor Minder" and apparently people really did a double take when an empty car in the parking lot would suddenly start its engine with no one around.

[TestDrive]

All this talk about block heaters finally made me recollect a conversation in 1989 with an Alaska resident -
Technology - Coolant Heater
Espar - FAQ's

[bhazard]

So what do you guys think? 500, 850, 1000, 1500 watts? Theyre all about the same price, $25 or so for 500 watts, 850 and 1000 are both about $31 and 1500 watts is about $35. Im thinking just go for the 1500w model and run it for less time.

[MetroMPG]

I'd say go big or go home!

The only potential downside to the 1500w unit might be tripping your breaker if there's anything else on. If the circuit is rated for the load, you just need to make sure you're using a cord rated for it as well.