Technical Cooling ?

Have an 18" fan on the small block. Fabing shroud for same. Thinking of going to 17" fan .would cooling be affected with smaller fan? Trucke

 

Exact same blade design? Of course it would. Whether it’s enough to matter is up to you.

 

If you are building a shroud and can make it any size, I don’t think diameter would be as important as pitch of the fan blades.

 

Biggest fan you can fit! I have never heard someone say they put to large of a fan on a car.

 

While the size of the fan is important, what matters more is the shroud vs. fan relationship. The leading edge of the fan should be just inside the shroud opening with no more than about 1" clearance between the outside diameter of the fan and the inside diameter of the opening. That clearance will allow for motor movement.

 

The fan can be wider than the radiator , just make your shroud fit the fan !!!

 

It's good thanks!

 

Using an 7 blade 18" fan now. 6 blade 17" wil give me a good 1". Trucke

 

I'm with @Bandit Billy on this one, all the cars I built I alway put the biggest fan I could.

Of course I always ran Pontiacs and I liked them running in the 170-180° range. Seemed I always ran the factory A/C equipped clutch fan with a heavy duty Napa fan clutch.

Never had one that ran too "cold" doing this. Although most of my Pontiacs ran 10.5 and higher compression too...

...

 

You already have over heating problems, in a previous post.
Now you want to go to a smaller fan, with fewer blades ?

Great idea.

 

I,m going to use the 18" if possible. Only can go 19" on the shroud hole unless I stretch it out somehow at the sides. Trucke

 

My Buick only has a 16" fan, no shroud. Does not overheat. What it does have is enough radiator that is clean. AND THAT IS IN OUR 100+ Texas weather.

Ben

 

Derale fixed bladed fans are your best friend!

 

, will keep that in mind ! Trucke

 

This helped with my cooling problem on long wait intersections or stop/go traffic. A smaller water pump pulley did more. 16” 6 blade

 

Pulled the electric off my coupe when I went back to carb. Used a Zips pump adaptor. 16 inch fan and cooling components fibergl*** shroud. Drove today 103 degrees outside. Ac on 165-185. 185 at an extra long light. Cooled right back down.

 

Never said his ''small block'' was over heating! JW

 

He did in an earlier post.
https://www.jalopyjournal.com/forum/threads/overheating.1321268/

 

OK

 

.....Just another reason to not start multiple threads about the same problem!