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Discussion Starter · #1 ·
Is there some shade tree way to determine if you have sufficent air flow going through your radiator? I have been experimenting with a shroud/no shroud, fan closer/farther from rad etc. The current setup has enough "suction" on the front side of the rad to hold a dollar bill up, but I am not sure that is enough. Any help would be great.

Thanks.
 

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Jeff
Im guessing this is about your 67

depending on what fan your running ...most problems seem to happen at idle in traffic ...a shroud should always be used ...is the rad attached directly to the core support ?? with out the spacer box .. if so buy a shroud from ground up and get a good thermal clutch and 5 blade fan ...skip any flex fans if you have room for the other.
short of going electric ...even though thats the best cooling in city traffic , sensor opperated .. full CFM when triggered .. rather the low CFM at idle with the mechanicals .

3 keys to cooling ..1-good flow 2-a efficient rad 3- good CFM threw the rad

Don
 

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Discussion Starter · #3 ·
Hey Don,

Yes, my rad is connected right to the core support. I have a long water pump so the distance between the pulley and the radiator is about 1 inch too tight to fit an electric fan in there. I did try, but I was only able to put the fan on one side of the radiator and although it was a 2300 CFM fan I still had problems (and the sensor had leakage problems). So I went back to my fan with a shroud...but even with a spacer on it the fan was still 3 inches or more away from the rad. So I put a larger spacer on, but then it cut into the shroud....so it had to go. But to be honest it sure seemed like the CFM running through the rad was about the same for either setup with the fan, that is why I was asking how to determine how much is enough.

Thanks.
 

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When it comes to overheating, generally, if you overheat while driving down the highway, it's a cooling system capacity/efficiency issue. If you only overheat while in traffic or very slow speeds, such as putting around the neighbor hood, it's more than likely an airflow issue. And just like Don said, always use a shroud. If you don't use a shroud, the fan will mostly pull air from around the engine bay and just circulate around the hot air and not pull any through the radiator. Think of the shroud as a device that makes sure the fan has no choice but to pull air through the radiator.
 

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Hey Don,

Yes, my rad is connected right to the core support. I have a long water pump so the distance between the pulley and the radiator is about 1 inch too tight to fit an electric fan in there. I did try, but I was only able to put the fan on one side of the radiator and although it was a 2300 CFM fan I still had problems (and the sensor had leakage problems). So I went back to my fan with a shroud...but even with a spacer on it the fan was still 3 inches or more away from the rad. So I put a larger spacer on, but then it cut into the shroud....so it had to go. But to be honest it sure seemed like the CFM running through the rad was about the same for either setup with the fan, that is why I was asking how to determine how much is enough.

Thanks.
Jeff
click on this link and scrool to the bottom of the page to view the last 3 photos
https://secure.wf-api.com/www.chevellecooling.com/52.html?sm=14001&psid=p28Pd4OFW0sEkO2oQlLR
I am assuming this is a big block with long water pump ... the last pic should give a example of a worst case situation of long w/p and no clearence .
the twin 12 set up would be the best solution to your problem .
the pusher fan your running may be a low CFM unit and pushers ane aprox 10% less effective and also block air when not being used ... lose it and make a switch to twin pullers .

Don
 

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Discussion Starter · #6 ·
Don,

You are correct, that picture is pretty close to what my clearance looks like. Just to be clear I did not have a pusher fan on, I had a puller that when it started ran full speed. I would also agree that the only what to get this to work right is to use twin fans because as you see the water pump does not leave room for a single fan. I think that might be my next path to follow.

Thanks for all the input fellas.
 

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if it keeps the car cool, then airflow is good enough.
a few years back, i was playing with blocking off the grille of my Monte to try to make it into a more aerodynamic brick. i discovered that if i run an air dam under the radiator support, i can totally block off the grille and the car felt slightly more stable than with the grille open and no air dam. but without the air dam, i need about 1/2 of the grille uncovered. i also played with a large piece of sheetmetal that went from the bottom of the bumper back to the rad support below the radiator, and i could get away with about 1/4 of the grille opened up- the car kept right at thermostat temp of 185 and the car really felt a lot more stable without all that extra air building up under the hood.
every time i pop the hood, i find myself trying to think of new ways to manage the airflow into and around the front of the car...
but all that only applies to when the car was moving- the stock fan and shroud kept the car cool at low speeds, but i ditched it for an electric fan off an 85 Celebrity- which also kept it cool- and i now have the radiator/expansion tank/dual electric fan setup off my 94 Caprice 9C1, and it keeps it right at the 200-210 degree range that my temp switch is set up for.
 
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