THRILLBILLY
1/2 ton status
definitely putting a 180* thermostat back in tomorrow just to get the best of running both options and call it done. thanks for the information! 
CK5
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What thermostat should I run on my 383?
- Thread starter nsxxtreme
- Start date
4xcrazy
3/4 ton status
Those direct drive solid mounted fans eat up your fuel mileage and performance as well.
With as much power as this thing has I'm not to concerned with the power it robs.
Here's the deal on those electrical fans that I don't get and would interesting to see some dyno results. Nothing in life is free. An electric fan may not be directly connected to the engine mechanically but it is directly connected electrically. When you turn that fan on the load is switched to the alternator. And it takes power to make power. Meaning the alternator isn't 100% efficient it going to use up some addtional power beyond what the fan uses to create the current to spin the fan. I think the real savings with those electrical fans comes in weight. The blades are usually made of plastic so they require less energy to spin. Also they don't have to spin all the time.
Cool...so you a marine engine expert? I may dive into replacing my boat motor here soon with something a little more powerful. It's got a 220hp 305 in there now and I'd like to stick a 300hp 350 in there.
63chevyll
1/2 ton status
This is a good thread, I'm.glad the 180 worked out, and I second keeping temp high
Ya I went with the 180 just because I do a lot of towing with this truck. Otherwise I probably would have gone with the 195. My engine tuner was recommending the 160. And has said he has run them on a bunch of different motors and never had a problem.
The thing with this debate that I find interesting is that a lot of people will change the thermostat with no ECM changes. Well I could see why that would be an issue. Electrical fans don't usually kick on til about 210. And timing and fuel curves are based off engine temperatures. But I haven't been able to find any conclusive data for any of the temps for an engine that is tuned for that temp.
4xcrazy
3/4 ton status
Alternators won't use up nearly the energy to spin as a direct driven fan blade setup, even one that's clutched.
I had a clucthed fan lock up on me once, it went bad, it shuddered the whole engine and drug it down, we were cruising at highway speed when it happened.
Some motors ran electric water pumps, takes that resistance of the water pump blades cutting through the water off the main drive belt, freeing up more power,
Not always just about weight savings.
Believe me, if you took that direct drive setup off and even just installed a clutched on, you would notice a lot more throttle responce and get-up out of that thing. plus better fuel mileage on what already sounds like a gas muncher
What your saying doesn't make much sense. Something that takes 20hp to spin will take 20hp wether driven by the motor or driven an electric motor. The alternator has to turn rotational energy into electrical energy which isn't as efficient as taking it from the source itself.Alternators won't use up nearly the energy to spin as a direct driven fan blade setup, even one that's clutched.
Kinda like having a gas motor powering a generator to power an electric motor. The best efficientcy will just be the gas motor to drive whatever is needed to drive.
But like I said before I think the saving comes in with the plastic fan the electric motor uses. It's light so uses less energy to spin and it doesn't need to spin it all the time. The mechanical fan is metal and heavy. So it take more energy to spin. I don't think I will be switching to electric fans anytime soon. But who knows I didn't envisions investing the type of money into this truck that I have when I bought it either. It started out as just a cheap $2k truck. It still looks like a $2k truck
But that might help keep the theives away too. I have a RR if I wanna drive something nice.
4xcrazy
3/4 ton status
an alternator does not have the air drag that a fan does, yes it still takes power to spin electric fans, but running off of battery power is easier than draining power from the engine through the water pump, which is also draining power from the belt driving off of the crank... which is where you're robbing the power from.
When an alternator loads up, it's not really slowing down the engine like a fan or water pump is doing, dragging it down, I have NEVER felt or heard mine anyways, load the engine down when I fire up ALL of the of the 1250 watts of lighting on my Burb, yes I can hear the alternator kick in and start working it's butt off to keep up a charge, which it obviously fails at over a short time, but there is nothing physically dragging the engine down through the alternator, it spins through magnets and coiled wire.
Gas motor driving an electric generator? hmm, well, I am pretty certain that they DO use a Diesel motor to run a big/huge electric generator to run trains,,, I wonder why that is.
I dunno, been wrenchin on different cars for the past 25 years, i'll let someone else chime in on this if they would like, maybe i'm just not describing it correctly, which is a good possibility with the way my head feels lately with this stupid cold.
When an alternator loads up, it's not really slowing down the engine like a fan or water pump is doing, dragging it down, I have NEVER felt or heard mine anyways, load the engine down when I fire up ALL of the of the 1250 watts of lighting on my Burb, yes I can hear the alternator kick in and start working it's butt off to keep up a charge, which it obviously fails at over a short time, but there is nothing physically dragging the engine down through the alternator, it spins through magnets and coiled wire.
Gas motor driving an electric generator? hmm, well, I am pretty certain that they DO use a Diesel motor to run a big/huge electric generator to run trains,,, I wonder why that is.
I dunno, been wrenchin on different cars for the past 25 years, i'll let someone else chime in on this if they would like, maybe i'm just not describing it correctly, which is a good possibility with the way my head feels lately with this stupid cold.
huh? Air drag? 20 hp is 20 hp doesn't matter where that hp comes from.
What your speaking of is a perpetual motion machine that doesn't exist. If it did you better pattent it cause you will be filthy rich. When creating energy it always takes more energy to create the energy then you get out of the energy created. The alternator is driving off of the same belt the fan is. Again the power you save by switching to electric is going to be the weight savings of not spinning a heavy fan blade. You will also save energy by not having to spin it all the time since it can shut off when not needed. You might also save some energy if they designed a more efficient fan blade. But other then that your electric fan is placing the load on the alternator and robbing your engine of power. The only way to get around that is to remove the alternator.
Again a watt is a watt. Your alternator is definately dragging down the motor when you kick that on. You just don't notice it because your idle control valve makes up for it. You can do a simple conversion from watts to horsepower. Or horespower to watts. Try going to www.onlineconversions.com if you are that interested.
They do that cause it mainly eliminates the need for a transmission.
the power rob of a high amp alternator drag is pretty minimal... whereas a bladed fan may "steal" 10hp to spin it, an alternator with a higher load is probably taking 1 hp or less to spin thru that extra load..
I dont know what minimal means. Around 780 watts is about 1hp assuming 100% efficientcy. The only electric fan I could find online was a dual fan which required 40 amps. 40*14.4=576 watts that the alternator would need to produce. The alernator isn't 100% efficient so the alternator would require more rotational energy drawn from that motor in order to produce that power. I'd say the alternator is probably about 80% efficient. So you would need about 1.2 hp to just spin those fans. Once a mass is moving it doesn't require aditional energy to keep it going. Once the fan is spinning you're now dealing with the frictional forces of moving air. Which will be the same for an electric vs mechanical. The difference will be the efficientcy of the blades.
With electric the fan can be shut off when its not needed. IMO that is where you get your real gains from.
No idea how much a metal fan takes to spin but I think 10 hp is high. I would guess more around 2-5 hp. Not enough for me to really care.
your WAY overthinking it... somehow your managing to argue with me, when your saying the same thing...
