Replacement cooling fan

[David Wiltshire]

I am about to replace the viscous coupled cooling fan with an electric one does anyone know the temperature that the thermostat opens?

[Moncha]

I beleive it's 160 degree thermo..

[rx7tt95]

If you find an appropriate fan setup that will work, please post the make and model number on the forum. I've been looking to do this for some time, not only for space but to reduce parasitic loss and load, especially when cold. Seems the fan adds a lot of drag in the first few minutes after starting the engine.

[Joe_Black]

What you'll lose in drag on the stock fan you'll pick back up on the alternator when the electric runs. The old adage "you don't get something for nothing" is very true in the auto world. If you don't understand what I'm talking about, turn off everything electrical in the VX while it's running and just listen to the engine for a bit. Then turn on the lights. Notice the difference? That's the alternator loading up and dragging the engine. The more current draw, the more load. That Isuzu fan is actually well designed. The trick is keeping the thermo area clean and lubricated so gunk and dirt don't build up causing it to run more than it should. And the best part is that as long as the engine is turning, so's the fan. Just my .02c!

[WyrreJ]

On my beater car with a little-ole 4-cyclinder, I found a sticker that says "turbo mode" to put over the A/C switch. The A/C's drain on the alternator is substantial enough to give you a nice kick if you have it floored and flip the A/C off, not unlike a real turbo spooling up.

[rx7tt95]

The alternator is always on regardless...it's not mechanically regulated. There is always drag regardless of the current pull needed by electricals. There's no clutch system like there is with the a/c. Most a/c systems at WOT application, turn off for a set amount of time, say 15 seconds. Yes it helps power due to parasitic loss, but it also prevents over pressurization of the system (a very baaad thing). The a/c has no effect on alternator output. A/C is completely mechanically driven EXCEPT for the fan logic, which may dictate that fans come on (if electrical) to keep temps at check due to higher loads. I see this as one of many advantages to electrical fans.

On a side note, I used to live in Vietnam and many locals would often drive their Honda Om's (little motorcycle scooters) with the lights off at night believing they'd get better gas mileage. Of course it wasn't true, but you couldn't convince them of that. Subsequently, there are many many deaths. Enough that the government actually issued a statement on it (no taxation so they couldn't really start a campaign)

I know I had a bried conversation with Tone some time ago and he didn't measure much of a difference between electrical and mechanical, if any so he went back to mechanical (if I remember correctly). But I can't ignore the fact that every modern sports car currently has electrical fans. Not only can you more finely control temp with variable fan speeds but you open up a buch of room too.

The only real caveat that I see with the electrical setup is that most modern cars with electrical fans use the ECU to control the fan's functioning, ie there's lots of different inputs and logic behind how they operate. From just one fan at low speed to two fans at high (assuming a two fan system). I know one fan manufacturer (it was probably SPAL) had a new, fairly sophisticated unit on the market but I doubt it would cover all the bases like a properly-designed, OEM from the factory system would.

[David Wiltshire]

The manufacturer I have found is Kenlowe they have been producing electric fans here in the U.K. for a long time. I have owned a number of high performance cars and still do and as far as I can remember not one had anything other than an electric fan. With the cost of fuel here in the U.K. at over $100 a tank I think the savings in fuel economy and the fact it will run a lot quieter has made me opt for the 16 inch fan produced by Kenlowe. As I have said in my younger days I built a hot Ford Anglia and bought a Kenlowe for it and was impressed by the build quality. If anyone is interested thier web site is www.kenlowe.com

[rx7tt95]

I've been doing a bit of research on alternators, electrical draw and hp losses. There are indeed some associated with current requirements although I have not found any definitive formula or rule of thumb. On the average, however, they're pretty small. Many drag racers go from mechanically powered devices to electrical, the best example being water pumps. Anyway, just thought I'd post that tidbit. I still think electric fans are a good idea :-)

[rx7tt95]

Ok, found something kind of interesting..I'd heard about it previously and JEGS is now listing it on their website. I don't quite believe the MPG and hp claims, but it's a variable speed fan and if it fits, should work quite well with the VX. Anyone know the radiator size off hand? Here's the link:
http://www.jegs.com/cgi-bin/ncommerc...84&prmenbr=361

If that doesn't work, www.jegs.com and type in 400-295 for a part number in the product search box.
Michel

[Joe_Black]

Okay, here's the deal on racers and drag cars using the electrical fans. THEY RUN OFF THE BATTERIES. Yep, that's right. When your sponsor dollars count on a win you eliminate EVERY bit of parasitic drag you can on the engine. Track races and drags have short demands on batteries for accessory power and they can be swapped very quickly in the pits or paddock. Now I know you're going to point out rallys and such as that. Well, rally vehicles and related run in production classes that often don't allow too much modification to the auxiliary systems. For example, I'm building a Group N car and pretty much if it came with an electrical fan that ran from the mains then that's what you're stuck with. Plus when you can't pit or find your support vehicle (and crew!), carrying a load of batteries if allowed kind of negates the parasitc reduction on the engine. Then you're in less of two evils territory. That's why you see so much induction and extraction cooling since high speed aerodynamics aren't that critical when you're slogging through the woods.

There is a formula for calculating mechanical load on an alternator and I know it involves capacity of the alternator, ratio of drive (alternator pulley to drive pulley) and current load (or average). If I can find it in one of my works manuals I'll post it. Somebody wouldn't have come up with the "underdrive" pulley if it didn't make a difference!

[vx69]

I believe the mounting surface of our radiator is around 14" W x 26" L. I have been doing a lot of research and looking for electric fans to fit the VX, so far I have found nothing to fit. I read that a general rule of thumb is that the electric fan must have a sealed shroud that covers 85-90% of the radiator surface, and that a puller fan normally runs better then a pusher. The best company seems to be Flex-a-light.

[Tone]

I’ve used FlexALite and even their high CFM did not cool as well as the stock fan on the VX and I saw no increase in HP or mileage.