looking to switch to an electric fan...how many cfm would be good for my mav with a 200 i6...no overkill pleaseee
You will want a minimum of 2500 CFM. Now remember these fans that you see in the speed parts books are rated without a radiator attached to them.CFM drops once its mounted to a radiator.The radiator creates a resistance/blockage to air flow that the fan sees so, figure a 12 to 20 percent decrease in CFM from the advertised rating. Personally I would get one that can produce at least 3000 CFM...Get a fan with a shorud as well. A Taurus fan would be ideal for your app...3500 CFM and fairly cheap out of a junk yard...And it has its' own shroud.
A four cylinder engine requires 1600 cfm; a six cylinder engine requires 2,000 cfm, a small V-8 engine requires 3,000 cfm and large V-8 engines require 4500+ cfm. http://perma-cool.com/faq/efans.htm
In my opinion, especially for a 200 i6, as long as the fan is moving, you should be fine. I have a junkyard fan from a "who knows what" 90s model 6 cyl and it keeps my .040 bored 5.0 plenty cool. More importantly, have a good radiator. Go aluminum, if you can. In other words, get the cooling system up to date before you worry about the fan cfms.
the recomended cfms listed on the perma cool site are just a guess. so much more goes into cooling than just the motor size and fan cfm. the efficency of the radiator is really important. a really big alum radiator is not going to need very much cfm to cool a motor.
the question was... "anyone know how much cfm for an electric fan"? so what is all the radiator talk about?...
You can have too much radiator and never maintain a good operating temperature without putting cardboard in the front of the core to restrict the air flow. I over killed my Falcon's cooling system and the temp gauge will bounce from 125 to 185 like a yo-yo all day with the fans turned off in 50-55 degree weather.
the radiator talk is about the original question being to simple. you cant just tell how much cfm is need based on motor size is what is being said.
you know that most people on here tought of a sweet looking aluminium radiator when he sed electric fan (i know i did ) but he should not need that with a inline 6 he probably just wants to gain a bit of power and some gas mileage
I didn't "tought" nothing...i was thinking..."sweet 302" when he said 6cyl...but i didn't mention it. ......
I put a 192* and it runs fine at 190*-195* in the summer all day even sitting in traffic. On cooler 50* weather the gauge will fall too cold when the 'stat opens and rise when it's closed. While playing with different temperatures, my butt-o-meter knows when I reach 205* without looking at the gauge, performance falls fast. Every engine has its own personally and mine likes 180* to 195* and no more.
Well if you don't like the cardboard look, you can always spray paint it black. This is how we deal with it in 18 wheelers. Either button up the winter front cover, or stick cardboard to restrict the air flow. But even then you can get to the point in temps outside where even that's not enough. Been-there, done-that a few times up north. When the temps get down to zero (& below), sleeping in a truck without freezing your ass off is a bitch.
