17" fan with 20 1/2" shroud opening?

[kaj750]

1969 Charger My car currently has a radiator that measures approximately 22 in across (overall). The car came with a larger radiator that measures approximately 26 1/4" (at the core) that I would like to toss in.
It has a shroud on it already. I was told the radiator will fit. I guess I'll find out soon enough.
My question is: the fan measures approximately 17 in across and the opening in the shroud is 20 1/2 in.
Should I be looking for a larger fan?

 

[Kern Dog]

I don't recall any of my fans being 17" but I do recall a few being 18". That allows just over an inch or room around the perimeter.

 

[davek]

How many blades on your fan? Like KernDOG said 18 inch on my 68-70 cars. Why 22 inch on a 26 inch opening? Did they add brackets to install a 22 inch radiator in the 26 inch opening? Any pics for us? Get the right radiator for your car.

 

[Geoff 2]

The closer the fan blades are to the shroud opening, the more air you will pull through the rad.

 

[davek]

The closer the fan blades are to the shroud opening, the more air you will pull through the rad.

Fan should be half in half out of shroud

 

[#41]

My question is: the fan measures approximately 17 in across and the opening in the shroud is 20 1/2 in.
Should I be looking for a larger fan?

No. That is fine.

 

[Geoff 2]

A chap on another forum did extensive testing on the fan in/out of the shroud. He found that it made no difference to engine temps. What does make a difference is what I said in post #2.
It should also be obvious that at some point when the fan to shroud gap becomes too large, the effect of the shroud is lost & the shroud does nothing for cooling. It is just along for the ride.....

 

[Kern Dog]

A chap on another forum did extensive testing on the fan in/out of the shroud. He found that it made no difference to engine temps. What does make a difference is what I said in post #2.
It should also be obvious that at some point when the fan to shroud gap becomes too large, the effect of the shroud is lost & the shroud does nothing for cooling. It is just along for the ride.....

My comments were in post #2.
You were #4 and 7.

 

[furious70]

Link to that experiment?

 

[33 IMP]

I would:
Bolt in the 26, and see how well the fan is centered in the shroud. Then, if there is room, I would look for a larger fan.
This is for your hemi car? Do you have a clutch fan?
I am assuming since it's got a 22 in it, that you have a 22 core support.
If this is an original hemi car, I'd leave the core support as is- if not, I'd open the core support up to match the 26" radiator.

 

[33 IMP]

I would also get the 26 pressure checked before I did anything else.

 

[Geoff 2]

Furious.
The experiment was done probably about 20 yrs ago. Result was posted on the Performance Years website in the Heating & Cooling section by George Kujanski.