Alright guys, here's the question: Have any of you converted your Sammi over to an electric fan? I have a lovely free fan that had previously been cooling a toyota V6 that will sit nicely behind the radiator of my 86 Zuki. My thinking is this: less drag on the engine equals more power to the ground and electric fan turns full speed all the time so more cooling at the crawl. The dillema is this however. The stock fan is on a clutch, does this clutch offer enough of an advanage over a direct drive to render my electric mod un-nesacery? On that other American built 4x4 (I won't mention the J word)that I used to drive, the electric fan was a must for crawling. I mounted it in front of the radiator and left the stock fan intact, only flipping the switch for the electric one when needed, the V6 had more than enough power. Any advice would be appreciated.
This is a popular subject. There's been much discussion over the years, pretty much along the lines you mentioned. A little searching on the various Suzuki boards should turn up a HUGE amount of discussion. The Taurus fan seems to be popular, but there are plenty of others that seem to work also. There's also the pusher versus puller configuration to consider. The 'puller' seems to offer more room for a larger fan.
Just wanted to share my experience with using an electric fan on my Sammy. I have a 92 model Sammy and been using en electric fan on it for 5 years now.
I used to overheat consistently when driving my Sammy (on the way to the trails) on the highway and could not understand why. I've had the whole cooling system cleaned and and inspected. Eventually to find out accidentally that when on a stock alternator (35A), the fan wasn't spinning fast enough. While the temp would go down on idle, on high revs the temp would go up. After switching to a 90A alternator, overheating problems went away. So Baratacus is right, if you're on a stock alternator, expect problems with the electric fan.
The electric fan does help with engine power. It also helps with river crossings. Best to put a thermo switch to it though so you don't burn out the carbon brushes due to continuous use (even when engine is cold and not needed).
puting a higher output alternator and putting a load on it will use just as much engine power.
It takes engine power to make electricity for your fan. In fact it will take more power to run the electric than the mechanical fan. Converting mechanical power of the engine to electric power at the alternator and then converting it back to mechanical power at the fan motor is much less efficient than running your fan straight off of the mechanical engine power.
There are situations where a mechanical fan can't be used, like with a long core radiator where you need more than one fan to effectively cover the surface area of the radiator, or if you don't have enough space to mount a mechanical fan between the engine and radiator, or any time a push through front mounted fan is required...
As far as efficency and output though, a properly functioning mechanical fan is going to be the best thing for your vehicle.
If you have an engine driven fan without some sort of thermally controlled clutch - which the Samurai does not have - you're wasting power turning it at highway speeds when there is already enough motion induced airflow through the radiator to handle the cooling chores.
If electric fans were that inefficient - would you care to explain why most recent production vehicles have switched to electric fans - even those with "north-south" mounted engines?
Just as one example the 2.0 litre J20A engined Grand Vitara '98~'05 uses an engine driven viscous clutch fan, but the '06~'10 production, using the same engine have a pair of electric fans.
Given the cost compromises that go in to designing & building vehicles, can you see a vehicle manufacturer going to a more expensive, less efficient cooling system - the electric fans are not as inefficient as you assume - especially when you consider that they spend more of their time switched off than they do on - even with the vehicle stationary and idling.
So... according to a little research a 50 amp draw on your alternator causes a drag on your engine equal to roughly one horsepewer. The fan on the other hand in a clutch configuration, drawing only when needed, pulls up to 15 horse out of the engine when engaged... on a big block! An old one! A little sammie four banger it would be closer to half to one horsepower. An electric fan pulls up to thirty five amps at startup. Hmmm, this seems like a bit of a moot switch. The reason for the vitara switching to the twin electrics as well as the Toyota forrunners and a whole host of other four by fours is this: As the front of the vehicles evolved to a shorter, wider configuration over the last several years (perhaps in an effort to make them apear to have greater ground clearance or aerodynamics, or both?),The radiators have gotten wider as well. This means that they need twin fans to move air over the entire surface of the rediator and a single central fan cannot do this. In addition to this, the Japanese automaker's traditional economy of parts means that if Suzuki or toyota can use the same fans for all thier vehicles and most of them are transverse engine configuration, then the remainder of them are likely to get electrics as well. Soo, with all that said, I do believe I will be staying with the engine driven clutch fan after all. Thaks for all the responses you guys!
Last edited by nmluckyduck; 09-29-2010 at 06:15 PM.
The reason for the vitara switching to the twin electrics as well as the Toyota forrunners and a whole host of other four by fours is this: As the front of the vehicles evolved to a shorter, wider configuration over the last several years (perhaps in an effort to make them apear to have greater ground clearance or aerodynamics, or both?),The radiators have gotten wider as well. This means that they need twin fans to move air over the entire surface of the rediator and a single central fan cannot do this.
I can't speak for the Toyotas, but, that's not the case with the Grand Vitaras - the radiators are roughly the same shape & size, and whilst on the 06~10 the twin fans do a pretty good job of covering the radiator, the same can not be said for the single fan in the 98~05.
The engine driven fan does move more air at low rpm than an equivalent electric - hence the need for twin electrics - but that does not explain the switch to electrics - which plain & simple, is fuel economy - you don't drive the fan when it's not required.
There are a couple of application notes & research papers dealing with this - I'll see if I find then and post a link for you.
fordem, you are absolutely right, I forgot to mention the fuel factor. I had no idea when I began contemplating this conversion that there was such a fine line to be drawn. I will maintain my current stock fan at least until I upgrade the charging system. If it weren't set up on a thermo-clutch I think it would be a more pressing issue as far as the power is concerned. My old jeep just idled so low and the cooling system was simply inadiquate for crawling that the electric became a must.
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