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Item Posts    Sort Order

crossflow radiator vs regular type

Posts: 87
Joined: 11/08
Posted: 03/02/13 11:25 AM

Does any one know of a set up with Electric fan on a cross flow radiator? I have a regular alum 4 core with electric fan and it won't keep my temp under 200! I was told that a cross flow is much better then top to bottom is this true?. I know someone makes a setup for early mustangs.

347 bored 40 over and can't keep it under 200... I'm told shoud not tun over 190 on a bad day..

New pump new everything  

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Posts: 455
Joined: 04/12
Posted: 03/02/13 09:25 PM

lets check the cooling system for function before tossing more money in parts..

when it gets to 190/200F.. does it loose coolant and overheat???

most cars don't come close to overheating until 245F...

does your radiator cap hold pressure??? squeeze the upper hose.. with the engine slightly warmed or warmed up... does it have pressure inside.. or does the squeeze just allow air to flow out and then back in as you release..    that would be a bad thing..

it must hold pressure.. until it reaches 8 to 10 PSI.. then release any excess into the recovery tank..  where it will be pulled back into the radiator when the engine cools off...


are you running a 180 or 192 thermostat???    

do you have 50% to 70% coolant to water mix... to allow the boiling point to be up around 260F

is your bypass hose hooked up and flowing.. NO KINKS in it..  there are some brands that are not quite the right shape.. and kink when installed..  blocking flow.. preventing the proper circulation of coolant until the thermostat opens...

warning.. electric fans cannot cool without a properly selected 180 or 192F thermostat..  a 160F thermostat will become wide open before the fans cycle on and you will have a runaway cooling system as the coolant will be flowing thru the radiator so fast that NEITHER the fans or the RAM air through the grill will cool the engine..

restrictors instead of thermostats just don't work....

i think we went over checking that the square corners of the head gaskets are sticking out from under the FRONT of both heads...  not the BACK of either head...   FRONT on either side..

this allows water pump flow to go all the way to the back of the block around all the cylinders on each back then up through the back of the head and forward to the intake crossover.. where it is either blocked by the closed thermostat and forced thru the bypass and around again  and again until the coolant is hot enough to open the thermostat and swap cooler for the hot. then the cooler will close the stat again allowing the fans or ram air to cool the stationary coolant in the radiator..

with the gasket on backwards... the coolant in the back of the block and the back of the head will not have enough flow to cool those cylinder... the back of that cylinder bank will overheat and destroy the pistons, rings.. cylinder walls and the heads..

now... a few more questions...

are the fans relay controlled... so the power wire circuits to the fan motors have larger conductors to allow the fans to spin at full power...

are the wires properly crimped to terminals.. not just wrapped and taped..   (sorry.. i have found a lot this way)  

are the fans turning in the proper direction..  again.. sorry.. but i have even found improper direction fans on belt drive systems..

do you have or can you borrow an infrared temp gun...  to verify the actual temp at the thermostat housing and the radiator.. TOP and bottom...

clogged radiator cores can be found with creative use of the infrared temp gun.. by going back and forth across the tubes.. if you find cool tubes when the others are HOT. you have found restricted tubes.. this does happen..

there are all kind of cross flow radiators..  please search one out that includes properly sized electric fans on shrouds...

but the Thermodynamics of the system cannot be overcome.. even with a big radiator..

lastly.. do you have any restriction in the fuel system that would drop the fuel pressure at high speeds.. leaning the motor out and causing uncontrollable overheating???  

Post Reply
Posts: 635
Joined: 07/06
Posted: 03/03/13 10:33 AM

Most articles I've read on installing later model crossflow radiators in 65 -66 Mustangs involve cutting the opening in the radiator header wider than stock and rotating the battery 90° by using a 67 type battery tray that orients the battery longways front to back. Crossflows are way more efficient and the hoses are on different sides instead of the same sides. So, also a different waterpump is used that has the inlet on the drivers side instead of the passenger side.

Sorry, Ihave seen better photos on this project but couldnt find the one I remember. Hope this gives you some basic ideas.

Wayne is absolutely right about the correct thermostat in an aluminum rad. I had a 160° stat and in winter, the car would never warm up to operating temp running cold and summer, too hot. A 180° helped. Probably needs a 190°.  

Post Reply
Posts: 87
Joined: 11/08
Posted: 03/15/13 07:46 PM

Thats great news thank you, I am going to inspect the hoses and such tomorrow and double check that its all working properly before I go and switch to a larger radiator and Electric fan set up. Thank you for the pages and information both of you.  

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