New 4 row Radiator, New Fan, New Water Pump and Stat - still running hot!

[rsavage]

UBTRIPN,
What kind of fan do you have? If it is a flex fan, I'd get rid of it and get a clutch fan from a truck with AC. They pull lots of air. Hope you get it all set.

[ubtripn]

I may do just that because I AM GOING CRAZY!!!!!!!!!!!!!!!!!!! I put the shroud back on, a 180 thermostat in, cracked the thermostat housing and had to replace it, jacked it up to burp it 10 times, still running over 200!! I need to validate the temp but I think it is right. For a 350 sb I have never had this much trouble. I put a cigarette next to the outside of the rad where it should be sucking air in and it was blowing it away, could I have it on backwards, I don't think so because there is a label on the blade stating - facing engine but the person who put that on probably makes next to nothing so who knows.

Does anybody have a pick of a flex blade installed I could look at?

I will get a pick of mine and repost in a bit.

It ran better before with a bad waterpump and fan with a missing blade on a 40 year radiator. What the heck????? I should be able to tow a mountain and I can't even drive 2 blocks.

Here is my fan - does it look right?

[OhOneWS6]

That fan looks backwards to me. It may be for a serpentine system. The water pump rotates the opposite direction with an OE GM serpentine system. A water pump for an OE GM serpentine system will have an identical housing but the impeller is different to work with the reverse rotation.

That looks like a short water pump. I believe all short water pumps are for a v belt and therefore should be the correct rotation for your truck. That's not to say the rebuilder did not put the wrong impeller in the pump and you have a short pump with a reverse rotation impeller.

There are aftermarket serpentine system that are made to work with a standard rotation pump.

[ubtripn]

I have nothing to lose flipping it. Does it look backwards to everybody else?

The belt runs from the crack to the alternator to the fan.

[OhOneWS6]

The pitch on that fan is backwards. It is the wrong fan. You can't fix it by turning the fan around. You need a different fan. Here is a pic of my mostly original 72 Cheyenne Super fan. That fan is for a reverse rotation water pump.

[OhOneWS6]

If you turn that fan around the blades are going to flex forward and eat your new 4 core radiator up real quick like.

[68 IRON]

Ok someone call him and tell him not to turn that thing around! Thats gonna make one horrendous noise...not the fan hitting the radiator, but what come out of his mouth when he finds out what he did! Pictures do help though...
No really somebody stop him!!!

[68 IRON]

Dang, we've all been there....so frustrated and determined to fix the problem that the solution is right under our noses. I hope he went to the store to get a replacement....I'm starting to sweat!!! This is nerve wracking!!!

[OhOneWS6]

I hear ya. He showed to be online when I originally posted. No response and now he is offline. I sure hope he read this first. This has all the makings of an expensive lesson.

[ubtripn]

Thanks guys, I got lucky, the distance kept it away, I will go get the right fan. Thanks for the concern, really, I mean it and thank for the solution, sincerely!!!!

[ubtripn]

OK, I have in my garage a 19inch fan with a fan clutch, shroud wont fit but I may as well give it a shot. I'm taking the other one back. I did not know 68's came with fan clutches. Thanks everyone for helping solve this.

[OhOneWS6]

Keep us updated. Glad you didn't damage anything. :wipes forehead:

[ItsRandy]

Originally Posted by ubtripn

I thought a thermostat either was open or closed not metering in between. Learn something new everyday.
Posted via Mobile Device

As someone else said, the thermostat temp is the minimum temp. After that it is supposed to regulate the temp so the motor runs at close to optimum (or design) temp. The valve in the thermostat is constantly moving as it tries to maintain a consistent temp after the motor warms past the design temp of the thermostat (160*, 180* etc). The radiator and water pump supply the coolant the thermostat asks for, all the parts work together, that's why it is called the "cooling system".

[ItsRandy]

Originally Posted by ubtripn

I thought a thermostat either was open or closed not metering in between. Learn something new everyday.
Posted via Mobile Device

As someone else said, the thermostat temp is the minimum temp. After that it is supposed to regulate the temp so the motor runs at close to optimum (or design) temp. The valve in the thermostat is constantly moving as it tries to maintain a consistent temp after the motor warms past the design temp of the thermostat (160*, 180* etc). The radiator and water pump supply the coolant the thermostat asks for, all the parts work together, that's why it is called the "cooling system".


Sorry about the double post.

[68 IRON]

I soooo glad it worked out! You acutally had me sweatin'! Now take it easy and keep coooool. Good job!

[ubtripn]

THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!! I had bought a used fan with a clutch for five bucks for no reason at the time. It is an inch larger in diameter so I couldn't put the shroud on but I slapped it on and it stayed at 180!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I could NOT have figured this out without you all, thanks you, thank you, thank you. I had given up. Then you all pulled me out of the hole. I cannot say thanks enough.

[ubtripn]

Its Randy - so what your saying is that its A SYSTEM =) gotcha Just joshin ya, thanks for the description, I had viewed it more like a light switch rather than a regulating potentiometer if you know what I mean. Your description helps a lot.

[MagmaJct]

I'm new to the board, but I'm already seeing that this topic, fan shrouds, is a repeating concern. I'm considering putting something together that will help teach the basic concepts as to why a shroud is important.

I've seen others mention that the 260s didn't come with shrouds new. I find this hard to believe, but that doesn't mean it's not true. It's just that it doesn't make sense for it not to have a shroud. Then again, fans didn't have a clutch at one time either.

[ubtripn]

Great idea. They do seem to be important.

Does anybody know if the 4X4's came with a bigger fan? Sinced I have one that is an in larger it would be nice to get lucky and have a shroud out there somewhere to hunt down.

[ubtripn]

Disregard, it appears 19 inch is the stock size.

[OhOneWS6]

Glad you got it sorted out.

[ubtripn]

Thanks again for all of the support!

[taank]

I went electric. I will never go back to a mech fan. 4 row alum radiator. High flow 165 stat. I run at 180 degrees
Posted via Mobile Device

[ubtripn]

Did you take the electric off another vehicle?

[Stocker]

Originally Posted by ubtripn

Does anybody know if the 4X4's came with a bigger fan?

Originally Posted by ubtripn

Disregard, it appears 19 inch is the stock size.

Negative.... my OEM fan is 18".... shroud opening is around 19 1/4" - 19 1/2".