Fan Blade To Radiator Clearance

Getting ready to weld mounts to frame for radiator. How much fan to radiator clearance should I leave. My thought was if close enough I wouldn't need a shroud. Is that correct? 350 sbc, 6 blade fan, and can center to fan blade.
Thanks, Lee

 

I have ran several cars without a shroud but anyone will tell you, a shroud is way better, specially down south.

I use to run 1/2 to 3/4" to start and tailor it from there. If you're running a flex fan, make sure there is adequate clearance when at higher RPMs.

 

I have 2 inches clearance between the rad and mechanical fan.

Also have a shroud and according to the cooling theory, half the blade should be outside the shroud for maximum effectiveness.

 

3/4"

 

I followed the same advice given by OneBad56. Works great. Go with the shroud.

 

Looks like time to open up the fab shop. Thanks for the replies.
Lee

 

3/4" to 1" depending on your motor mounts

 

How many times have you had to fight a little 7/16 belt between the radiator and the fan blades. I set mine around 3/4" like Fred said. If the fan holds a dollar bill to the other side you know its pulling well. My question would be is this fenderd or open?How much area of the radiator is the fan covering really helps determine if you need a shroud.

 

I have about a 1/2" on the wagon. HRP

 

Make sure you leave enough room so you can unbolt the fan to change the water pump without taking out the radiator if ya gotta.
-Pat

 

I have 3/8"....I have seen 1/4" clearance before.

 

The fan is according to my figures is drawing 70 percent of the area. Fan area = 227 sq.in. and the radiator 320 sq. in.
Lee

 

On most of our cars it's 300x easier to take the rad out.

I have about a inch.its tight but fits.I run a shroud and it still gets hot

 

Use a shroud if you can, it gets too hot here in the summer as you know!

 

Air will take the least path of resistance, so without a shroud instead of air being sucked through the radiator it will be pulled in from the sides. Some cars get away without a shroud but if you can put one on it will be a lot more efficient, especially in August.

Don

 

No kidding, I'd rather spend the extra time to remove the radiator and gain the extra room than have to repair/replace it after you punch a hole in it.

 

Bingo!....

 

......And DON'T use a cheap ass flex fan.......
Fucking things are dangerous!!!..

 

You need enuff room for a wrench and also enuff to remove the threads from the water pump flange, bolts should be as short as posible and maintain proper thread protusion through the flange, 3-5 threads past the back side of the flange. Also you have to consider removing the fan, spacer, and bolts as an assembly, from the pilot shaft on the water pump. So...3/4" the lenth on the pilot shaft plus 1/4" for the bolt heads= 1". that my .02 worth.