Heat engine block for efficiency?

[bennelson]

Here is the other car I did't let people's opinion of me stop from happening.

This car was half '87 Geo Spectrum and half '89 Chevy Spectrum.

It was the first time I ever did any body work on a car. Mostly grinding rust and screwing on aluminum sheets. I wanted to do something with the paint that would camoflage the work done on it. The car was mostly white already, so I painted the hood white and cut out contact paper to make a cow spot template.

Everyone in public loved the cow car! It was anti-road rage! People would smile and wave at me on the road.

The car was retired on Sept 11, 2002 after the engine self-destructed on the interstate.

Last summer, I was at a friends bar-b-q and he told me he saw the cow car just a mile or two from his house. We drove over and found it parked in a driveway. Nobody was home, so we couldn't stop and say hello.
I am assuming that somebody loved the paintjob and bought it from the scrapyard. I have no idea if it runs or not, but I hope somebody else is enjoying it now.

[Frank Lee]

I get the impression one or some of you are thinking of using block heaters to prevent the engine from cooling down overnight, instead of letting it cool down then heating it briefly before you go the next morning... well, DON'T!

It will take more energy to maintain that warmth all night than it will to warm it from cold in the morning. Why? Because the greater the temp differential between object (engine) and ambient temp, the greater the heat transfer (loss). So the most efficient way to use the block heater is to know how long it takes for it to warm the engine from cold to as warm as the heater is going to heat it, and turn it on that long before departure.

[bennelson]

Right,

I was thinking some sort of a timer so that it turns on a certain amount of time before leaving in the morning. That was it isn't running all night, just runs long enough to get the engine warm.

Not sure how long that would be. I suppose some experimenting is the next step.

[MetroMPG]

My experience: no more than 2 hours (my small 3-cyl engine = small heat sink, though). YMMV.

[bennelson]

OK - it's freezing out right now.

I broke out my Killawatt and plugged in the block heater.

Turns out it is a 500 watt. Seems like a lot of heat. I can hear it running!

Is that a bad thing? I am always afraid anytime I hear weird noises from my car.

[RH77]

Originally Posted by bennelson

I can hear it running!

Is that a bad thing? I am always afraid anytime I hear weird noises from my car.

That sound means it's working

Mine does the same. Consider your vehicle as a very inefficient Power Plant upon cold-soak, vs. the more efficient grid to get that vehicle up to temp sooner with the EBH, so that the sum total of energy used and emissions is fewer to get that vehicle up to optimum efficiency (or normal operating temperature).

For my car, that is about 2-3 hours. I can hear the heating element sizzling the coolant shortly after plug-in, but that's normal. With the automatic, torque converter lock-up happens so much faster, which equals higher efficiency. The same should apply for the manual folks...

RH77

[bennelson]

I just found my spare lamp timer.

This one says it is rated for 15 amps! Most of the cheap-o lamp timers are only rated at a few hundred watts at most.

My engine block heater is 500 watts.

I am planning on now plugging: my block heater into an extension cord, that cord into the timer, and that timer into the KillaWatt.

That way I measure the combined electrical usage of the block heater and timer (yeah, I know the timer should use almost NONE, but I want to measure it anyways.)


Who can suggest how long I run the block heater timer for in the morning? The engine is a 2.2L 4 cylinder - and the car is parked in the driveway, not a garage.

Also, how much of the year does it make sense to run the block heater? Would it help in efficiency in the spring and fall too? Is there a certain temperature, above which, one stops using the block heater as an engine pre-heat?

-Ben

[MetroMPG]

Have you seen this thread?

Mini experiments: 300w vs. 800w block heater warm up time ...

I'd wager that anything more than 2 hours is overkill.

[MetroMPG]

As to question #2, I'd use the block heater year round (though you can likely cut the plug-in time down dramatically in the summer - I'll have to chart that this year).

There's a reason the Prius stores some of its hot coolant in an insulated tank and circulates it back into the engine... regardless of whether it's January or July.

[TomO]

Originally Posted by MetroMPG

Have you seen this thread?

Mini experiments: 300w vs. 800w block heater warm up time ...

I'd wager that anything more than 2 hours is overkill.

Agreed, I only run my EBH for ~1-1.5hrs depending on outside temps during winter. This summer, I might have to cut that time down to only 20 minutes since the garage should be around 70°F all the time.

HERE is my thread on my EBH installation and results.

The first tank after installation showed a good improvement of a few MPGs, not to mention, the fact that you get heat almost instantly helps as well.

And for a few months my work even let me plug my EBH in so I could save some gas....that is, until someone complained that I was getting special treatment and had to stop. [rant]I think it's ingrained in some people not to be efficient nor to understand efficiency's effect[/rant]