Technical changing cooling fan -- Updated

Some times you have to make parts ,
Some times have to set down & Think out side box .
I know might be hard if Limited to Tools.
May be switch to a signal Serpentine belt set up , I know it will change all pulleys
& Ac ,
Look threw Rock Auto multiple manufacturers Over years ,
I have took Multiple pulley apart to get the pulley size I need, Drilled spot welds , redrill bolt Patterns.

Try straight Water , I have seen 15-20 degs in drop over Antifreeze

 

do what you want, but the speed way fan will fix the problem... it's an inch thinner and would allow you to remove the spacer....that and it'll move 10 times the air across the radiator... it'll suck a beach towel in the grille like panties on a camel toe

 

looking at this pic...when that fan flattens all its doing is blocking air flow...

 

The fan flattens at high speed. He writes it is a low speed/idle problem.

 

They're usually stainless steel blades, not tin or aluminum. I hear lots of horror stories about them, but I've had one for 50 years now and never an issue. Another for 15 years and no problem. They rarely cause any issues related to cooling or overheating. The issue is somewhere other than this type of fan. Either not enough radiator, or clogged radiator. Or no shroud, or fan not sitting correctly inside the shroud. Or no way to evacuate hot air from the engine bay, or many other causes.

 

When it come to the Look a like
6 blade Flex & Derale Fan from
Summit
Jegs
& other Vender
Check the Rivets Not being set/ smashed correct !

 

I'd personally still do a cooling system flush. It cleans any oxidation and gunk from your system that will slow heat transfer. Air Conditioning is a higher stress on your engine and cooling system. A flush will confirm you're getting the best heat transfer possible in the system, if it's still doing it then you can worry about airflow.

 

Pontiac used a flex fan , heavy duty cooling , don't recall any complaints then ..

 

^^^^^
Grill Opening & size
Same with Rad ,
Vs
Ops was Not engineered for Ac

 

100% right about the grill and radiator not ment for A/C, but its what I got to work with. I am pretty sure its the rpm of the fan and water pump. This fan should be plenty for a inline six with no horse power. My pulley ratio is under driven a little, it needs to be overdriven quite a bit. I have a second thread going about pulley dimensions and I believe I have it figured out. Now to find a pulley and get the belts sizes straightened out. I need a 6" or smaller pulley for a short water pump V8.
At idle there should be no flex in the blades, 700 rpm.

 

Even a smaller grille opening can run cool if the area around the radiator is closed in to ensure any air coming through the grille can not escape around the sides of the radiator. I had some issues with the small radiator and grille opening on my Austin sedan with SBC power. Once air came through the grille it hit the radiator fine, but some gaps around the radiator allowed fresh air to bypass the radiator. I closed in those gaps to force any air to go through the radiator and never had anymore cooling issues.
My radiator core is only 16"x17" and the core is 2.5" thick to accommodate the small surface area. It never runs over 195 degrees.

 

I have rubber dams all across the top and side so all air passes through the core. Like I said, once moving or the rpm comes up, it cools right down. I would leave it as is, but the a/c warms as the engine does. At idle ( 750 rpm ) the water pump is running at 730 rpm. Just going to 6" pulley will speed up the water pump to 859 rpm, drop down to a 5 3/4" pulley would bump it up to 897 rpm.
I measured the fan, it's 18" across, some reason I thought it was a 17", it doesn't have much pitch to the blades.

 

another ghost post speedway fan and you are done... my 37 with 462 ground pounding, tire roasting, hp runs cool in the 102 degree vegas heat with the ac on.... I'm fixing the same problem with my wifes 55 t bird.. just got the speedway fan today... tomorrow I will no longer have a over heat issuse with her bird..

 

I getting ready to place the order, I'am going with the Vintage Air solid 6 blade. The Speedway has
1 7/16" to the front, 3/4" to the rear. Vintage Air is centered 1" each way, thats what the VA tech told me. The Speedway fan will be to close to the core.

 

you are correct, I lay'd one on the counter, the speedway I got only goes 5/8'' to the rear, with a total width of 2'', I'm a vintage air dealer , but have never used one of their fans... nice to know about it...it's good you are addressing this as every time the AC stops blowing cold you hit the max on the high pressure side of the compressor.. this will kill the compressor.. so are just gonna replace the fan and see what works??? interested in the results...

 

on the T bird,... didn't get it done yet... I decided to go to a 4 core radiator,new fan aluminum manifold. electronic dist. coil and plug wires...I'm rebuilding all the front end suspension on my 61 t bird,.. re doing the engine mounts on my 59 F100, trying to get it lowered, trying to finish metal work on my 58 chevy to get a finish dead straight last coat of primer..
on my 53 the head pressure would climb setting at idle, even though the motor tempt was fine... so I put 2 pusher elect. fans that come on when the ac is on, like the new cars...it can sit and idle with the ac on till it runs out of gas and never over heat, and head pressure stays under 300

 

The new fan from Speedway came yesterday, 24 hours from order to the door! Its pretty nice looking, and is a 50/50 split front to back, ( they should advertise that fact, it would be handy to know for guys with clearance issues ). I went with a 17" steel six blade replacing a 18" flex, a 6.25" diameter pulley replacing a 7.125" diameter, and making a new shroud for the smaller diameter fan. It will spin the water pump and fan a little more then 100 rpm faster. The new fan has a more aggressive pitch to the blades so I am hopeful this will work out.

Our school bus at work have electric clutch fans that turns on and off by the A/C pressure sensor or engine temp. I've seen 450 + psi high side when the fan relay goes out. We change more compressor then we should due to cheap relays and worn out clutches, an old fashion clatch fan would solve a lot of problems. This is exatly why I don't let the engine heat up even though it's not boling over.

 

did you get her done???

 

I got the new fan, still waiting on the pulley to show up. I have the new shroud laid out on the metal, I need to sleep on for a bit before getting out the cutters. Hope to make progress this week.

 

So I finally had time and gathered all the parts need to finish this up. I purchased a Vintage Air 17", 6 blade, steel fan, a 6.25" water pump pulley, new water pump and sheet metal for a new shroud. I switched out a 18" flex fan and leaking water pump.

I believe the problem has been solved, it never got over 185 setting idling for a while, though the hood was off. A/C was plenty cold and even cycled the compressor while idling. The smaller pulley will speed up the water pump and fan just under 100 rpm, so that helps a bunch. Shroud has a 17 3/4" diameter, and the fan is dead center of the opening. There's enough air blowing now you can actually feel it being pulled in the grill, the flex fan wouldn't do that. I do have rubber dams to go over the top of the radiator, had to pull them to get the hood ornament off so I could pull the hood out of the way. The Vintage Air fan blade has pitch from front to back, the flex fan blade was about 25% flat across the front and the rest was pitched. I believe that made the difference, at idle the flex blades couldn't have been flexing at 750 rpm.

 

So now you hat to get it running hotter?

One of mine runs 185. Was designed to run around 210-220.
Thinking about changing stats. At least make sure it’s not hung open.
More efficient at that temp

 

Thanks for the update! Glad you seem to have got it sorted, I’ll keep an eye out for you cruising now that it’s staying cool