Radiator Fan

[Stewart G Griffin]

EDIT:
response temporarily withdrawn.

[fxrsrider]

Well either way... Nobody seems to be giving me that answer.

Option A
Step 1.  Determine what temp you want to run at.
Step 2. Install appropriate thermostat per your answer to above.

Option A1.
Step 3. Install a mechanical fan that pulls air through the radiator.

Option A2.
Step 4. Install a clutch fan that matches your mechanical fan's direction and operates within the temperature range indicated in Step 1. (note: a clutch fan is optional)

Option B.
Step 3. Install an electric fan.
Step 4. Install a temp sending unit calibrated to the temp determined in Step 1 such that the fan turns on at the appropriate temperature.

Option B1.
Step 4. Install a switch on dash that controls when the electric fan turns on.

Option C.
Step 1. Follow Steps 1-3 of Options A & A1.
Step 2. Install an electric fan on the grill side of the radiator/ac condenser (if applicable) that pushes air through the radiator towards the engine block.
Step 3. See option B.

Option D.
Put the fan that "overcools" back on and drive your truck.

[fxrsrider]

Well either way I need the thermo stat to open and I need to [know] if the clutch fan is correct. Nobody seems to be giving me that answer.

Most clutch fans look the same.  The temp range that the clutch is designed for is determined by the metal coil in the center (like the old mercury controlled heating and cooling thermostats that you may find in old homes).  Unless you provide manufacturers and part numbers, no one will be able to tell you if that clutch fan will serve your needs.

Per the link you provided.  The fan you show....the listing states that the fan is not recommended for engines larger than 250ci.....so, I would suggest you find one recommended for 350ci or more.

As well, that fan is a "standard, clockwise" rotation.  It's not clear if you need that or a "counterclockwise" rotation.

[enaberif]

*sigh still no straight answers*

I am running v belt and need clockwise.

[fxrsrider]

Well that is the thing....I know the fan blades are opposite to one another and I had to take off the fixed fan because it was over cooling my truck...

Option A:
Put that fan back on, nevermind the clutch, drive.

Option B:
Put that fan back on, put a clutch on...

http://www.summitracing.com/parts/flx-5555
http://www.summitracing.com/parts/hda-2747
http://www.summitracing.com/parts/hda-2797
etc...

...drive.

[enaberif]

You can't clutch that fan. That fan will not allow the thermostat to open.

[Stewart G Griffin]

Ok, now that i thoroughly read your question i've determined that you ARE NOT running a serpentine setup AND you are running a conventional v-belt with conventional water pump.  Correct?



Where did you get the fixed fan in the picture?

RE-EDIT:
i guess the better question is where did you get the clutch fan in the picture which has a tag of "76 chevy truck" on it?

[Stewart G Griffin]

i just checked my 83 fan as well as the one that came with the 305 and they are both also pitched differently than the clutch fan pictured.

[enaberif]

Ok, now that i thoroughly read your question i've determined that you ARE NOT running a serpentine setup AND you are running a conventional v-belt with conventional water pump.  Correct?



Where did you get the fixed fan in the picture?

RE-EDIT:
i guess the better question is where did you get the clutch fan in the picture which has a tag of "76 chevy truck" on it?

The fixed fan came on the truck. I know that there was A LOT of previous stuff done to this truck that was very questionable and this could possible be one of those things.

The picture with the clutch fan came from ebay which I know is also not necessarily a reputable source.

Is your 83 serp or v belt?

[Stewart G Griffin]

1) Ok, in that case i would look for other fans that will fit 73-86 trucks.  i think the ebay one may be incorrect.  They may have meant 96 truck.
i don't think clutch fans were used until 80's ish, but by looking for fans starting in 73, we can look at the pitch angle.

2) my 83 is conventional v-belt.  i don't think serpentine was used on trucks until after 87?

Now, i'm wondering how are you sure that the thermostat won't open?  If the thermostat won't open wouldn't this mean the engine would eventually overheat?

[enaberif]

1) Ok, in that case i would look for other fans that will fit 73-86 trucks.  i think the ebay one may be incorrect.  They may have meant 96 truck.
i don't think clutch fans were used until 80's ish, but by looking for fans starting in 73, we can look at the pitch angle.

2) my 83 is conventional v-belt.  i don't think serpentine was used on trucks until after 87?

Now, i'm wondering how are you sure that the thermostat won't open?  If the thermostat won't open wouldn't this mean the engine would eventually overheat?

Because the coolant would be low and I would top it off and run the truck and it would be low again. It wasn't loosing coolant. You can tell when the thermostat opens because you can literally see the water flowing BACK into the radiator.

I was able to verify this as I replaced my 195 thermostat and with a temp gun watched as the housing hit 195 and the thermosat opened and the water flowed.

Since your 83 is v belt and you say the pitch is different I'm going to assume that when looking at the front the slant of the blade goes right to left not left to right? Like my original fixed blade?

[Stewart G Griffin]

Yes---All of my fans are pitched like your original fixed fan.

But i'm a little confused regarding the thermostat issue;  i thought that if the thermostat is closed then this means the water is ONLY circulating thru the engine, not the radiator---which means the engine would soon overheat?

[Irish_Alley]

to say you "cant" over cool an engine is kind of a misstatement.  keeping the engine temp too low and the fuel wont conver into heat like it normally would. heat is energy released during a combustion,  so the cooler the engine runs the more heat that gets removed via water and cooled down in the radiator now and that heat is replaced by more heat from the next combustion. so if you have to remove heat it will get replaced by more heat and youre equivalently waisting energy.if we're talking intake temp thats a little different cause the cooler the more dense meaning more fuel you can add. the reason we have to keep the temps down is cause of metal problems and the most efficient temps would surpass the failure temp of most metals

But back to the fan, whats your coolant:water ratio?

[Irish_Alley]

and has it always ran cold?

[Stewart G Griffin]

At this point i would like to rescind and nullify all my previous comments and just sit back and observe.