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Radiator to fan gap

tom jaffeux

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Need some information. What would be a good gap between the radiator and clutch fan or is it best to use a flex fan and can I use a shroud with a flex fan
 
I am not fond of the flex fan. Bought a new steel one to go back in my runner. No clutch straight drive. The fan should stick out of the shroud just a bit. Sure other's have the measurement for that. After putting the A/C in this car and first firing it up the throttle stuck open and it ran away with it self for a second and heard a loud squealing sound. Thought it was a fan belt turns out the fan was hitting the front of the A/C compressor. So wanted a little more space between the fan and water pump. So got a 2 inch is all they had. Put it together then heard a tick tick sound. Like some one was tapping on metal. After some inspection the fan blade now was hitting the shroud. So took it to a friend and we milled off an 1/8 inch in his mill. Now all is fine. 160 degree thermostat. The motor idles and runs well.
 
This is recommended. I have 1/2" and just fine though.
Screenshot_20210601-174426_Chrome.jpg
 
Hey diesel lv are you running a flex fan or clutch fan ? With or without a shroud
Thanks for the information
 
I have a serpentine setup w reverse rotation fan. Using 19" 11 blade nylon fan from Chevy truck w 496. My engine is a 610hp 496 stroker, using factory shroud w the Chevy fan direct mounted to pump due to no fan clutch short enough. 180° thermostat, runs in town n light to light around 195° and on the highway at 178° in 110+ temps.
 
Need some information. What would be a good gap between the radiator and clutch fan or is it best to use a flex fan and can I use a shroud with a flex fan

Find a 18-1/2" factory 7 blade fan and clutch, use the factory shroud and 180° t-stat. It will keep any combo cool as long as radiator is sufficient size.
 
From the face of my fan clutch to my rad is 1/2"....no clue on the fan blade to Rad distance, the blades are exactly 1/2 in and 1/2 out of the shroud though....runs cooler than normal operating temp!
 
Need some information. What would be a good gap between the radiator and clutch fan or is it best to use a flex fan and can I use a shroud with a flex fan
Are you starting from scratch? If so my advice would be to have the radiator installed and measure the distance from the face of the water pump pulley to the radiator fins...then find a clutch that's 1/2" to 3/4" shorter than that. That should put your fan blades in a good place inside the shroud
 
Try to use all factory type parts. Don't try to redesign the system that the factory spent millions engineering and testing on tens of thousands of cars.
They always use a clutch fan/shroud.
Flex fans have always been a cheap way to bypass the more expensive clutch setup.
Flex ok on a drag car that doesn't see constant use, especially at all rpms in around town driving.
Also 50/50 mix of the proper coolant and always use distilled water.
 
Thanks to all for the information it’s got me going in the right direction
 
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