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I have a set of electric cooling fans left from an old race car and was wondering how much of a gain could I get if I converted my blazer from the traditional fan blade and clutch to an all electric setup. I assume some gains would be offset by the additional load to the alternator, but would it still be worth it?

I don't think you will see any efficiency gains, assuming the fans are similar. It will take x hp to move y CFM of air to provide cooling, whether the fan is mechanically or electrically driven. The mechanical to electrical conversion in the alternator to drive the electric fan is not 100% efficient, so the engine wil have to make slightly more power to provide the electric fan the same horsepower.

The advantage of the electric fan may be that you could have more control over it than the clutched version. So if the switch to electric allows you to use the fan less while still keeping temperatures acceptable, then you may see a small gain.

The advantage of the electric fan may be that you could have more control over it than the clutched version. So if the switch to electric allows you to use the fan less while still keeping temperatures acceptable, then you may see a small gain.

I wonder how much quicker warm ups will be if your not running the fan when the ICE is not warm. Or then I guess the thermostat is taking care of that.

If the clutch is operating correctly, the fan generally should not run if the ICE is not warm. My old truck had a clutched fan. It did spin the fan for about 15 seconds after starting on cold days before the fluid in the clutch began to circulate, or something like that. I never ever heard it come on in hot weather.

Good info everyone, thanks. I think I will leave the fan as is for now and save the conversion for when the fan clutch fails and rather than replace it I'll just convert then.

I would convert it quick if you have the parts laying around. The fan load on my Ranger is absurd when it needs to run. That in its self is not bad. But the 5 mins before it goes full bore and the 5 mins after its reached cool down coupled with the heating cycles means in a warm engine running down the hwy or in city traffic means it's engaged a lot for no reason. Reason being,,, The fluid clutch is slow to react. While a viscus fan clutch is far better than a direct drive with no control. It's still a very sloppy system. This tech has left the industrial and heavy HVAC worlds decades ago concerning pump control, converyer and fan control. Be it manual, semi automatic or so called full auto control. I laugh when I see a viscus control now days and replace it with a VFD pronto. I can't believe they are still used in cars and trucks now days. They are just flat out cheap junk.

Test: Go get a salesman to take a cooper s out to follow you around. Hell romp on your truck and have the cooper driver match you. Get them nice and toasty. Pull them up side by side,,, pop the hoods and watch the fans. I bet you have a electric fan on there as soon as you can get it done.

As I'm sure you know. You can have the fan come on by temp and or system psi. One thing that is a problem when converting is more times than not the water pump will fail soon after a electric fan conversion. The reason is very simple. The water pump has spent it's life worn into a fan load on it. Remove the fan and the bearing/bearings fail thus causing the mech. seal to fail. And you will never see it coming. So plan on replacing the water pump.

As for basic install. Find a conversion that will allow you to use your OEM fan shroud. At min. use a temp sensor. For all out use temp and psi. With temp first inline. PSI as a system backup. Then mount the temp sensor high on the rad with psi lower in the rad. Psi near the bottom of the rad and temp mid point. If that can't be done mount both in the lower rad hose with a slip fitting. Never use a surface rad mount temp sensor.

If my Ranger was still my daily driver this mod would have already been done. And it will be done the next time I do a timing belt change or the water pump fails. Which ever comes first. I did not replace the water pump the first time I did the timing belt. Screw that. :)

Of the conversions I've seen over the years. It's always been good for a 1 to 3 mpg improvement. Not to mention a more peppy ride.

It's worth it, if you can swing it. :D And one of the very best mods you can do. Much better than basic aero modes on the brick of a rig. If I'm lying,,, I will let Wayne slut slap me. :)

psy

psyshack - that's exactly what I was thinking, was just looking for some sort of confirmation but from someone who had done it.

It seems like it would make sense to eliminate the fan clutch and fan - I haven't seen BMW put one on a car since 2001, and they eliminated it for economy and engine temp control (but added an electronically control thermostat... OY!)

Well I might have to just take the plunge and drop that sucker in and give it a shot. I don't think it will fit with the factory shroud, but it does have some built in shrouding. It has a temperature control temp sensor - just have to figure a good way to plumb it in. It is a dual 10" setup so it does move air quite well, I'm hoping I can arrange the on/off cycle to be very quick.

I'm thinking that I will see quite an improvement, or at least hope to for the effort involved. Now just have to save up for a fresh h20 pump and do it.

Thanks for the input.