Cooling upgrades

[Drew Pojedinec]

I'd normally post on the FE forum, but it is looking a little dangerous there today....  perhaps the heat is getting to folks.
Thankfully here in southern Georgia it isn't that hot.  Heck I still have jeans, boots, a tshirt and my button down shirt over that.  But it is hot enough I had to break out the large straw hat.

So speaking of heat.  My new engine build isn't thrilled with the 100 degree days either.

Situation is as such:
Engine is a 446 stroker, which I've posted about plenty recently.  Cooling system is a stock waterpump, 185 thermostat, Griffin radiator, dual flex-a-lite fans rated at 1100cfms and draw 8 amps, pushing and mounted in front of radiator.
Timing is 18 initial and 32 total in by 2850rpms or therebouts.
The fan's barely kept the old engine cool enough, and that was 100-150hp less of an engine.  I knew the fan's would be marginal at best, but I was mostly concerned with getting the engine running last time I was home.... figure I'd work out the details later.

-When running hard out on the country roads the engine is running peachy.  180 and lower, even 170 which kicks off my fans.
When pulling into town the engine is obviously overheating, gauges immediately shoots past 200 and engine begins to idle badly and I need to keep a lil throttle in order to keep her from stalling.  When parking car, overflow tank is full and pushing some coolant onto the ground.

This issue seems straightforward, the fans aren't doing their job well enough.  Solution I will pursue is changing them with two 12inch Spal fans which are rated at 1277cfms and draw 14amps.
https://www.summitracing.com/parts/spu-ix-30101505

Yes I know pulling is more efficient, but I like pusher fans because I have more room there, and I like the appearance better.
I suspect the stock waterpump is suffcient, and also suspect the Radiator is up to task.  (feel free to comment on either)

Question
My painless harness has a 20 amp relay for each fan.  (actually it has three relays for some reason).  Each relay says 12v 2X20amps.  I'm not fluent in electrical, so I assume this is 20amps, but I guess it could mean 40amps?
Is this sufficient for the task or do I need to upgrade the relays?

-Next issue
Due to running a radiator that has a radiator cap, and also running a surge tank (mostly for looks to be honest) I have two radiator caps.  I put a 14psi on the surge tank and a 7psi on the radiator.  I used the 7psi cap because I didn't want to overpressurize a surge tank.
My issue with this is that when parking and all coolant goes back into the system there is 4inches of air in the radiator, which isn't right since I have the surge tank.... so I obviously didn't think that through too well.
Plan for the future is to put the 14psi or higher on the radiator so it never leaks and putting the lower pressure cap on the surge tank and running the overflow hose from the surge tank.  No coolant leaks in or out of the engine are apparent.
Question
Is this a decent plan to keep the radiator topped off or does anyone have a better idea?


Any input would be greatly appreciated.
Thanks a lot!
Drew

[blykins]

Could you fit one of those 4000 cfm Taurus fans in there? 

Good call on the other forum.  I think it's everyone's time of the month in there. 

[Drew Pojedinec]

Here is the issue with a single fan on my car...
You either need to trim the hood latch support if it's a pusher.  Or the fan needs to be super slim in order to not hit the waterpump if it's a puller.
That is why I kinda like running dual fans.

I have 2.25 inches between radiator and waterpump pulley.  I have 3.25 inches between hood latch support on the pusher side.  Otherwise a junkyard run would certainly be in order.

I've got a lil time to figure this out, I have to attend a class in New Orleans this whole next week.  (Leadership and management for Merchant Marine officers.... blech, what boring stuff)

[e philpott]

Like the daul spals .... my Merzie pump just fits between the two fans like it was made for it , the fans kick butt on my half fill block

[jayb]

I think you've got the right idea on both counts.  The Spal fans are like tornadoes, they will really move the air through the radiator and should solve your cooling problem at low speeds.

On the relays, the contacts are rated at 20 amps, but there are probably two poles (sets of contacts) in the relay, and maybe only one is used with the Painless harness.  Just guessing.  One relay per fan is what you want to do.

I also think that putting the 7 pound cap on the surge tank should keep your radiator full, since the surge tank is higher. 

[BH107]

The Ford Contour fans are a good option for an OEM type fan and fit the Galaxie radiator pretty well. They also are offset so give adequate clearance to the water pump pulley. Plus they are cheap!

[Drew Pojedinec]

On the relays, the contacts are rated at 20 amps, but there are probably two poles (sets of contacts) in the relay, and maybe only one is used with the Painless harness.  Just guessing.  One relay per fan is what you want to do.

There are technically three relays all marked the same, one runs to each fan, and I forget what the third does (I wired it up a few years ago).  I'll assume they will be sufficient until proven otherwise.
Ben, thanks for the tip on the contour fans, I'll look into it.

Another part I forgot to mention, last time I was home I was in a hurry to get the engine installed/fired/cam broken in and I got to drive the car.
Might seem like I was in too big of a hurry.... but I spent 2 years saving for/building the engine, so the prospect of being 99.5% done and not driving the car before going offshore for a month was abhorrent.
Today, while scratching my head and staring at the engine, I realized I used a 5.5inch march crank pulley and a larger water pump pulley....
Duh.
Perhaps not the entire issue, but certainly not helping at all being way underdriven.

So ordered a 5.5inch waterpump pulley and will get some more potent fans and I suspect I'll have no other issues.

Thanks for the input.  (I'll always figure this stuff out, but it often helps to make it public... seems like I flesh out my issue faster this way for some weird reason).
Drew

[blykins]

Always good to have someone to bounce ideas off of.    I've got a couple good engine builder buddies who I call on occasion and run ideas past.

[Katz427]

FYI I had to test a whole group of the various electric fans over a period of probably 4 years. I worked for a supplier that made the cooling fans for Ford. We probably evaluated about all of them including Spal. The clear winner was the fans designed by a company in New England called Air Research. The blades had a longer chord length , and were swept. The particular design was chosen for the Taurus. It flowed a lot more air and developed a lot more pressure. I noted that most of the fans were rated at a by the manufacturer at a very low pressure. Many of the fans were in stall at a very low pressure. If you had a 1 row coil, that was about the limit. The Spal fans were rated better than most and actually had more chord length which gave them more pressure before they stalled. The Taurus fan was the clear winner as it lost less flow as the thickness of the radiator (resistance) increased. The upshot is that those "skinny" blade fans really fall flat on their face as resistance increases.

[cjshaker]

These are all just my opinions, so take them for what their worth....about .05 Peso currently

I'm not a fan of aluminum radiators on street cars unless they're really oversized. Copper is much better at heat transfer (check out this link: http://www.physicsclassroom.com/class/thermalP/Lesson-1/Rates-of-Heat-Transfer). Flex-a-Lite fans are junk. A 185* thermostat is fairly high, it won't be fully open till a little bit higher. The heat being generated from your engine is likely being sucked into your intake, causing the idle and stall issue when hot.

For what it's worth, I'm using the March underdrive pulleys on my Mach 1 with an all iron 427, pushing 500hp. I don't have any heat issues, and it's been around 90*+ with 75%+ humidity for the last few weeks. I have no issues running the car at these temps. Although I don't get into bumper to bumper traffic, I do do a lot of slow cruising through towns. I'm running a 160* thermostat, factory oil cooler, stock type copper radiator, Edelbrock water pump, previously mentioned March pulleys, and an aftermarket full blade flex fan, not one of those thin blade types. In VERY slow traffic on a hot day, the highest I've seen is 205*. That's in a cramped Mustang engine compartment with ceramic coated headers.

[Heo]

Finally Dough, Someone that agree with me on the
copper vs aluminium

[machoneman]

These are all just my opinions, so take them for what their worth....about .05 Peso currently

I'm not a fan of aluminum radiators on street cars unless they're really oversized. Copper is much better at heat transfer (check out this link: http://www.physicsclassroom.com/class/thermalP/Lesson-1/Rates-of-Heat-Transfer). Flex-a-Lite fans are junk. A 185* thermostat is fairly high, it won't be fully open till a little bit higher. The heat being generated from your engine is likely being sucked into your intake, causing the idle and stall issue when hot.

For what it's worth, I'm using the March underdrive pulleys on my Mach 1 with an all iron 427, pushing 500hp. I don't have any heat issues, and it's been around 90*+ with 75%+ humidity for the last few weeks. I have no issues running the car at these temps. Although I don't get into bumper to bumper traffic, I do do a lot of slow cruising through towns. I'm running a 160* thermostat, factory oil cooler, stock type copper radiator, Edelbrock water pump, previously mentioned March pulleys, and an aftermarket full blade flex fan, not one of those thin blade types. In VERY slow traffic on a hot day, the highest I've seen is 205*. That's in a cramped Mustang engine compartment with ceramic coated headers.

But a flex fan, especially a big one, eats up lots of otherwise free hp!

http://www.network54.com/Forum/215655/message/1066184641/Car+Craft+Cooling+Fan+Dyno+Test

[Lenz]

I still get too hot idling for "long" slow puts through town and heavy traffic.  I also am running a 160 thermostat, fabricated shroud and using a stock pump with an aftermarket flex fan.  I've not taken it to the point where I've overheated it but I do know that it just doesn't like to keep up unless I'm moving along, then no problem.  I had a guy tell me that some of the stock replacement pumps are junk and they won't move enough water at idle (something about the impeller material I think?), and I am also beginning to think that I want to get away from the aluminum radiator as this isn't the first time I've heard about efficiency for heat transfer there.

[machoneman]

I still get too hot idling for "long" slow puts through town and heavy traffic.  I also am running a 160 thermostat, fabricated shroud and using a stock pump with an aftermarket flex fan.  I've not taken it to the point where I've overheated it but I do know that it just doesn't like to keep up unless I'm moving along, then no problem.  I had a guy tell me that some of the stock replacement pumps are junk and they won't move enough water at idle (something about the impeller material I think?), and I am also beginning to think that I want to get away from the aluminum radiator as this isn't the first time I've heard about efficiency for heat transfer there.

Lenz, where do you live? I have 3 like new SS flex fans, all with different pitches, that I tried on my '70 Stang. I switched long ago to a an OEM type thermo clutch fan and love it for both cooling and low sound. All 3 fans were loud at cruising speeds of say 2,300-2,400 rpm, this over the sound of a worked near 500HP 358 Windsor with Flowmasters!  I'd be glad to ship them to you for a try if you'd like as they will (and are) just collecting dust in garage and they will not go back on the car.

[afret]

I've tried 3 different radiators and they all seem to work well.  I had the stock brass radiator recored to 4 rows, an aluminum 3 pass radiator with 2 rows of  1" tubes and now I have an aluminum single pass radiator with 2 rows of 1.25" tubes.  I had no problem cooling the 482 with a Contour fan setup with all three radiators.