Re: Converting from belt-driven fan to electric fan

I want to convert my Subaru Hatch (1989 GL 3-door) from a belt driven fan

> to an electric fan, in order to help it warm up faster in the cold weather > we have been having lately. I also believe that it may save a couple MPG > (the car gets 21=>28 MPG depending on road speed and whether I have to > use 4WD). > > I can get a fan for a Paseo pretty cheap, but will have to add a themostat > and all the wiring. All in all, it looks like I can do this for > Any ideas? > > Oh, and out of all the cars I have, this is the only car (other than my > Scion) that the A/C actually WORKS! And it's the only car that won't be on > the road in the summer! Figures, eh?

I doubt you will see much of an improvement in either the warm-up time, or the fuel economy. Once the car is moving, the fan is almost a non-factor. And when the car is cold, the thermostat should prevent water from circulating through radiator.

If you decide to go ahead with the conversion, you will also need to add a switch to turn on the fan in response to the needs of the A/C. My modern cars with electric fans and A/C all have high side switches that turn on the electric cooling fan when the A/C high side pressure goes up to some level. An older Audi I owned, just turned on the electric cooling fan anytime the A/C compressor was engaged.

Ed

Reply to
Ed White
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My sister has those electric engine block heaters that you plugin to a wall socket when she parks the car during cold Canadian winters. I haven't seen in personally, but she tells me it works fine.

Reply to
EdV

I also don't think you will see much of an improvement. The thermostat should be closed when the engine is cold and then it will modulate to control coolant flow to keep the engine at temperature once it warms up. It doesn't matter how much air is going through the radiator on a cold engine since the water is only moving through the heater core until the thermostat opens.

You also have a clutch on the fan that is temp sensitive. When you first start it up the fan may roar a bit until the fluid in that clutch warms up (a minute or so) but past that point the fan isn't doing much.

If it were mine I would leave it alone. It has worked fine the way the factory designed it for close to 20 years... Make sure it is in good tune and drive like there is an egg between your foot and the accelerator pedal and you will save much more fuel.

Steve B.

Reply to
Steve B.

 Make sure it is in

_______________________

About that last suggestion, Steve: We are joined at the hip with that statement. But how can one drive like there is an egg on the accelerator without having the vehicle behind you end up in your back seat?

I live in Fairfield County and believe me, when the light turns green, even on an old two-laner, the roar of cars leaving the line resembles several 747s spooling up for takeoff at once! The floor-pan beneath their gas pedals must have an extra indentation from how often that pedal's been FLOORED!

I've also been watching my tachometer more on takeoffs - not allowing it to rev above 2000-2500 before letting up on the gas and letting the ole' automatic downshift. Accelerating through lower gears is a LOT quieter than pressing the pedal almost all the way down and not letting until the car is at the speed limit. It's just that most drivers behind me don't have the patience for my fuel-saving ways. ;)

-CC

Reply to
ChrisCoaster

Make sure it is in

_______________________

About that last suggestion, Steve: We are joined at the hip with that statement. But how can one drive like there is an egg on the accelerator without having the vehicle behind you end up in your back seat?

I live in Fairfield County and believe me, when the light turns green, even on an old two-laner, the roar of cars leaving the line resembles several 747s spooling up for takeoff at once! The floor-pan beneath their gas pedals must have an extra indentation from how often that pedal's been FLOORED!

I've also been watching my tachometer more on takeoffs - not allowing it to rev above 2000-2500 before letting up on the gas and letting the ole' automatic downshift. Accelerating through lower gears is a LOT quieter than pressing the pedal almost all the way down and not letting until the car is at the speed limit. It's just that most drivers behind me don't have the patience for my fuel-saving ways. ;)

-CC _______________________________

It is a paradigm thing. Until folks get used to changing the ways that they have driven for all these years with cheap gas, they will continue to be annoyed by folks that drive with less lead-footedness. Eventually they will change with the rest or they will continue to be annoyed (not my problem) and continue to lose money on gas. Tomes (back from the Usenet dead)

Reply to
Tomes

The faster you get into top gear and the longer you stay in top gear, the better the economy. Even a jackrabbit takeoff is preferable to taking three minutes to get up to speed. Maintain a decent following distance to reduce the need for braking.

Reply to
AZ Nomad

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Why so much $$$ for that stuff? You may never recover your costs in fuel savings if you spend that much.

Here's how I'd do it: Either get a thermostatic switch from an old drip coffee maker or microwave oven (check ratings because they trigger at anywhere from 140-212F), or use a thermistor (electronic parts supplies, dud battery packs from cordless tools). BTW any relay from a microwave oven probably can't carry the current needed by a fan because AC amp ratings for relay contacts are equivalent to less than 25-50% the DC ratings.

You'll probably have to build an electronic controller consisting of at least a transistor and diode to drive the relay coil (wire diode across coil to keep it from destroying the transistor). A thermostatic switch can be wired almost directly to the driver transistor, but a thermistor needs a comparator circuit to set the trigger temperatures, plural because there's one temp. for turning on the fan, another, lower, temp to turn it off. That also means hooking up the comparator (think LM339, which is four comparators in one package) as a Schmitt trigger. You'll also need to find the relay that turns on the A/C compressor and use its signal to turn on the fan whenever the compressor runs.

Reply to
larry moe 'n curly

Yeah, I was thinking about one of these, too. There are a couple (a few?) types; one that replaces the dipstick, one that installs as a metal sleeve in the radiator hose, and another that replaces a feeze plug. Which one? Which one???

Reply to
Hachiroku $B%O%A%m%/(B

Where's the fun in that?!?!?!

Actually, it is a 3-speed AT (and I *MEAN* 3-speed!!!) It tends to get into top gear rather quickly, and stays there even if you almost stop for yield signs.

I'm getting varying fuel economy. For the 'paper route' it gets about 23, unless I have to use AWD when it snows/ices, where it drops to ~20. For open road driving (I rarely drive >50 MPH, since it's spinning at ~3,700 RPM) it squeaks out 25-26. It hasn't been run for a while and had crap gas in it, so it gets better the more it's driven.

Reply to
Hachiroku $B%O%A%m%/(B

I live in a rural area and drive it mostly at night!

But, like I said, where's the fun in that?!?!

Two of the other cars I have on the road: 1988 Supra Sport Roof (no Turbo) and 2005 Scion tC. Vrooom, Vrooom!

One car I have not on the road: 1985 Corolla GTS...VROOOOOOM....

Reply to
Hachiroku $B%O%A%m%/(B

And a good thing! Where ya been?

And if you remember, I am a bit of an 'enthusiast' (er, about as enthusiastic as you can get with an 1800 and a 3-speed AT...)

But because of where I live and how I drive, I usually manage better than usual mileage anyway.

Reply to
Hachiroku $B%O%A%m%/(B

Like Prius drivers?

Reply to
Hachiroku $B%O%A%m%/(B

Why does everything have to be fun?

Reply to
Jeff

Definitely not the dipstick heater. Waste of money.

A freeze plug heater is pretty good for most people, but make sure you don't punch the freeze plug back into the block. On vehicles where you can specify a block heater when you order it, usually it is a freeze plug type. This is one of the options that cost less to buy initially than to have it done in a shop after you buy the car. That & they're a pain in the butt to install due to lack of space. My old (2005) Chevy full-size van was ordered with one, and GM now sees fit to install every block heater with a thermostat on the power wire. The heater won't work above 0 F. If you get one without a t-stat and have it on all night, you'll have warm air coming out of the vents in short order. With a t-stat, it's just "warm enough to start".

The one that's a metal sleeve in the radiator hose sounds like a tank-type circulation heater, which is for Arctic conditions. That's an industrial-strength heater. Unlike the freeze-plug heater (which relies on convection), this one has a little heater & pump that runs all the time you're plugged in.

Reply to
Bob M.

I would use the dipstick or freeze plug kind. The kind that installes in the radiator hose is not warming up the coolant that will circulate when the car is cold started.

Reply to
Ray O

Aren't you the same guy who always want people to get a life?

Reply to
EdV

Getting a life doesn't mean wasting resources. I also suggest they take the subway, bus or other public transit, walk or take a bicycle, too.

Jeff

Reply to
Jeff

But, I'm too young for FLA!!!

Reply to
Hachiroku

Um, you're kidding, right?

Reply to
Hachiroku

That's why I drive cars that get better than average fuel economy.

Reply to
Hachiroku

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