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Vanco, all what you just said sounds correct (based on years of experience in the automotive industry). I have yet to see an electric fan able to move more air than a fully engaged clutch fan @ high engine RPM's (would draw too many amps and rob too much power). Efficiency can be dialed in though and the big advantage is they can run @ full output while engine is at rest. It will be interesting to hear how it does in the summer, please keep us in the loop. TimQuote:
Originally Posted by VanCo
I was reading this http://www8.basf.us//PLASTICSWEB/dis...01a5e180004891 trying to convince myself to go electric. Mind bending! The importance of the shroud, how crucial is "tip leak" to fan efficiency, the hub size, the blades shape and ratio, horse power vs blade width etc... everything is in there about fans and shrouds! If you dont mind a bit of science :wnk:. It is like candy to me.
VanCo, according to this paper, your set up should be a big improvement on the mechanical system in term of efficiency, it is hard to believe that our 14-1/2" fan with a hub of 6-1/2" stubby 4" long blades (5 only), 1" gap around the tips, could beat it, even a 2500 RPM .
Size and pitch of the blades + RPM determines how much cfm. Blades on electric are small in comparison. It would take a huge electric motor to spin a stock engine driven fan blade @ 3,000 rpm. Electric does have advantages though and modern ones are pretty effective for what they do vs amps they pull.
I agree.Quote:
Originally Posted by timsrv
It has been proven (dyno testing) that mechanical fans can use up to 30 engine horsepower to spin. I am guessing (butt dyno) that the van's mechanical fan uses around 10 horsepower. My 16" electric has a motor rated at 12 volts and 17 amps. That calculates to .3 (generous) horsepower.
They are both doing the same job, moving air (yes there are a number of aerodynamic, and thermodynamic properties involved). For simplicity, if one is using 10 horsepower and the other .3, even factoring in gross inefficiencies you would have to conclude that the one drawing 33 times the horsepower is providing more airflow.
This power difference is why it is important to make an electric fan as efficient as possible (much more efficient than the mechanical fan) in addition to flowing a high CFM of air.
Another plus for electric set up, particularly Tim's, is the easier access to the front of the engine for belt change, tensioners adjustment, leak check etc...., also the combo shroud/fan has to be a piece of cake to remove/ install VS. the 2 pcs shroud + fan + clutch. No?
Yeah, you get much better access to the front of the engine when running an electric fan. I have run fans close to the radiator and now shrouded a bit away and all combinations give improved access over the factory set up. All have been easier to remove too.
Also a benefit, you do gain a couple MPG's going to electric.
With all the benefits, if my newest setup can't cool properly on a grade, in heat, fully loaded, I'm going back to the stock fan.
Anther not negligible selling pointQuote:
Also a benefit, you do gain a couple MPG's going to electric.
I hear you. I don't know anybody else here, beside Tim with his admittedly over loaded rig, who has truly put to the test as many different set ups . Or though with a turbo and no intercooler you are setting the bar pretty high :lol:. Then if it works well for you, it should be easy-peasy on our NA motors :LOL2:Quote:
With all the benefits, if my newest setup can't cool properly on a grade, in heat, fully loaded, I'm going back to the stock fan.
I have had great results with my electric fans/custom stainless steel fan shroud.
But it's VERY important to make sure that all other parts of your cooling system are in good working order.
I had the following replaced: HG, the famous "Yuba City Ability Radiator" high efficiency re-core, new coolant overflow head (coolant fill) and hose, hose of death and custom aluminum HOD outlet plate...
Again, super-special thanks to Timsrv for all his knowledge and input on this (see link below).
This may be old news for some, but for newer members here is a link to my electric fan mod:
http://www.toyotavantech.com/forum/i...quote_icon.png Originally Posted by mistershmi http://www.toyotavantech.com/forum/i...post-right.png
<trestlehed, did you ever get an electric fan set up and dialed in?>
Yes! It's all set-up as written in this thread. One key thing to remember is that the success of my mod
was founded on the 4 row high efficiency recore from Yuba City, CA. Then add the dual electric cooling fans, a custom stainless steel radiator shroud, adjustable relays and... Xanadu! (I prefer the Exit Stage Left double live album version). :lol:
If you cheap-out/cut corners on any part of the cooling system, prepare for disappointment.
http://www.toyotavantech.com/forum/s...nd-thermostats
2nd fan location:
I need to add a fan for additional cooling when off road.
No issues on the road, loaded, uphills.
Up hills in 4wd, going slow, causes the temp to rise and only drop very slowly once flat.
I don't have space in front to cover the entire radiator, so where would be the most effective location for a small elect fan? Inlet side? Outlet side? Center? High? Low?
Radiator fans are more efficient as puller than pushers according to manufacturers. Most of them recommend the fan to be installed on the "engine side" I do not know how the fan is setup on the diesel engine but here is a pictures of an assist fan between the clutch fan and rad.
Attachment 6656
Hope that help
Regarding the picture above, I should point out this fan does very little in the way of "assisting". It works very well as an engine bay ventilator (prevents heat soak issues). I have it set on a "count-down" timer to run 15 minutes after the van is shut-off. I have tried running it on hot days when I get stuck in heavy traffic (low engine rpm) with my AC on. Unfortunately, in that situation the van still gets too hot (both fans together don't do enough). The only way to keep the van at a reasonable temp is to either shut off the AC or put the van in neutral and hold engine rpm @ ~ 2,500 (when stopped or coasting). If/when I do that the factory clutch fan effectively brings the temp down (moves a lot of air), but that electric fan (mounted in that way) will not. BTW, I do not run this set-up without a shroud (just had it off for the picture). I use an OE shroud and it fits inside nicely. Tim
Following up on my 16" electric fan and shroud install. I went on a camping trip to the San Rafael Swell in the Utah desert recently. The trip is about 350 miles round trip, with a lot of up and down canyon driving. The temp was in the low 80's. I had about 1k pounds of people and gear. 65 to 80mph speeds.
The fan did well, as well as it can really. It isn't exactly up to my standard though. It didn't get any hotter than the factory fan, but I feel like it will when it gets hotter. It may be fine in a naturally aspirated van.
The issue is air flow at speed. Electric fans count on air flow through the radiator at high speeds. This minimizes the fan cycling while on the freeway and such. This fan ran nearly constantly at high speed. That means any increase in ambient temperature, there will be an increase in engine temp.
To get the fan to stop running at its max, I need more air flow through the radiator. I plan to make a sheet metal tunnel from the front grill slots, to the radiator. I think I will also make a scoop under the bumper. I would just make a scoop by the radiator, but I'm thinking when the van breaks wind (tee hee) it creates too much turbulence to effectively scoop air.
The AFCO Scirocco radiator and Flex-A-Lite Sirocco 365 fans/schroud fit in the Van. I removed a bracket, upper passenger side, front, that was in the way. All air conditioning parts are also removed. There is around 3/4" clearance around the radiator on all sides. The lower hose seems ok but having the port on the correct side would be nice.
I haven't done any real product testing. This project van still has a ways to go. I will give more details about the mounting brackets if it works well.
Some initial observations:
The fans are Loud, and seem powerful. They aggressively pin a dollar bill to the front of the radiator.
I wired the Fans to the battery instead of the ignition, they run for around 12 minutes after the car is shout off. The thermostat controlling the fan on/off is in the fill neck, the port in front of the radiator cap.
The original clutch fan can still fit. Maybe, in an electric fan failure, I could limp home with it. The electric fan blades pop off easily leaving some access for the clutch fan. I think the clutch fan will fit in the spare tire with a little blade grinding.
Very nice :thmbup:
Just something that came to my attention when you mentioned 12 minutes running after shut down. would it be worthwhile to have an accessory electric pump running the fluid thru the engine and radiator as well? After all, the fans are only cooling static fluid in the radiator, and it take a much longer time to cool the fluid around the probe at the filler neck. I see on the pictures that you kept the originale size alternator, what size batterie are you running? How many Amps are the fans drawing?
Just picking brains up before diving into my own project :whistle:
And yes very nice bracketry work! Clean!
It sure looks like changing an alternator would be a whole lot easier.
Lol, that was my concern too. Just a good rule of thumb for anybody running electric fans to upgrade the alternator. If you have a factory Denso or Denso rebuilt (actually rebuilt by Denso), then I would consider it barely adequate. I would never recommend running one of those elcheapo rebuilds or "lifetime" rebuilds sold at the discount auto parts stores as they will not hold up. Performing the Delco-Remy CS-144 alternator upgrade would be a good idea........especially if those fans pull more than 8 amps. Tim
PS: It doesn't have to be a fancy custom alternator like mine, just find one with the similar housing in a junk yard and use that. That alternator was popular on the older GM products. If you pull one from a junk yard, probably a good idea to put new brushes in it. Tim
Researching the Flex A Lite website for a 16" fan I came about this nugget:
"A few rules of thumb that we'll pass along from our experience:
Don't use an electric fan as the primary fan on 4-core radiators. It overworks the fan to try to draw air through these extremely restrictive radiators."
It reminded me of this old timer at my radiator shop telling me : It's all about air flow through. Under highway or racing condition (high airflow) 4 row are ok, in the city or off-road (low airflow) not so good. That's why they stopped using 4rows core in cooling challenged vehicles like the van long ago.
Anyway plowing along in my project of "single shrouded electric fan on 4WD radiator" . I just got another 4WD radiator to use as a prop in my 2WD. I'm ordering the Flex A Lite 398 16"Syclone and related control bits, I will upgrade the alternator to the Delco-Remy CS144, wire the fan to the batterie so it keep running after shut down to prevent heat soak, and I want to run a aux. electric water pump (only after shut down) to keep running coolant through the radiator while the fan is running. I will need some help for this part as I am a bit of a "sparky" when it come to electrical. Any idea on what pump and how to plumb and wire it ? Not decided on a temp gage or alarms yet.
I personally would not consider an electric water pump to be worth the effort. You would only get circulation through the block while the thermostat was open anyhow. If you rigged one up to your heater hose, it could be made to circulate after, but the heat lever would need to be left in the "hot" position for it to work (unless you have rigged up an external heater core like THIS). Tim
This is starting to interest me greatly now that temps are averaging above the 80s. I notice a huge temperature gain in the cabin after I let the van sit after driving.Quote:
Originally Posted by timsrv