cooling for 351 windsor stroked

[NMattison]

my radiator is speced at 19" h x 26" wide from my mauf at ac do i need a super built cooling radiator to keep this thing cool? any help would be great thanks

[Roscoe]

Look, I know you are new here and only posted twice but in order for you to get an intelligent answer you must provide all the necessary information in an understandable format such as:

I have a 351W stroked to 392ci. I am running a standard water pump and radiator with a 180 deg thermostat. I will be driving it mostly on the street and not racing. Should I upgrade the radiator to one of those aluminum ones? Do I need a larger one than normal based on my engine?

You see by the example above how easy it is to understand and digest what you are trying to say? With this information we can give you the answer you are looking for. Now you try it.

And by the way, what is a "mauf at ac"??

Welcome to Club Cobra,
Roscoe

[NMattison]

thanks roscoe for the constructive criticisim well i am building 351 windsor stroked to a 392 iam using an edlebrock victor series water pump #8843 my thermostat is not purchased yet buti can use a 180 or 190 whatever. my measurements from a&c in ny said my size is 19w x 26" H i am using an tremec tko so do i need a special radiator ? my engine builder said i cant get a radiator too big any suggestions would be a great help

[Roscoe]

I think you will be fine with a two row aluminum. Now I have an A&C also http://www.priveye.com/cobra.htm and I am using the 19 x 26. I started out with a Griffin from Summit for 185.00 but that one started leaking after about a year or so.

I went to Afco Racing http://www.afcoracing.com and they took one of their standard aluminum ones and modified it. They put on -16AN fittings top and bottom, blocked off the filler cap (you don't need it) and added a draiin petcock. Total cost was around 255.00. They did a nice job.

I plumbed the system with -16AN and use a 180 thermostat.

Roscoe

[Mr.Fixit]

Aluminum or copper/brass, it doesn't affect the cooling ability as much as you might think, only a few percent. (Difference between a 19"x26" and a 19" x 25") The biggest problem is airflow, it doesn't matter how big your radiator is if you don't have a good fan setup. You will run cool on the highway, but get hot in traffic. A good puller fan or two and a SHROUD and you will be ahead of the game.

[Roscoe]

Actually Mr. Fixit is correct; and I overlooked this area in my post. A fan is VERY important. I wound up with a Derale spiral fan. Very hi volume. I can idle with the fan on all night and it won't go over 180. On the road, as long as I don't get into traffic, I don't need the fan at all.

Stay away from pushers.

Roscoe

[Charlie]

There is nothing quite as instructive as road testing. Mr. Fixit and Roscoe are absolutely right, the real key is airflow. But you will never know till you go drive it around. As long as you already have the radiator and the water pump and the engine and the . . . . well, what have you got to loose? Just go try it and see if stays cool. If it stays cool at speed and heats up in traffic, then you need more fan, not more radiator. Thats what I found I needed in my case.

[fordnut]

Don't get sucked into using under drive pulleys such as March they will slow down the coolant flow . no matter how much air you move acorss the radiator it will still heat up in traffic. Your water pump must flow the max coolant your radiator will handle.

[DAVID GAGNARD]

NMattison;

I have played with water pumps-pulleys and radiators for two years to get my car where I could drive in parades and around town without overheating..... One BIG mistake is putting underdrive pulleys on a street car. They are strictly for race applications only..... Your crank pulley should be the same diameter or no more than one inch less diameter than your water pump pulley and you will have no problems....

Tried three radiators and four or five electric fans before figuring out I just was not turning the water pump fast enough... Very expensive lesson but now I know better....

David

[MidOHasp]

I am running a 408W stroker and had mounted the alternator way up high with a March bracket. This required switching the output of the surge tank to driver side and running hose along the front frame rail back over to passenger side, up around and back down into top of radiator. We totally redid this old FE surge tank for our windsor and literally blew it off the top of the stat housing 10 times (not enough metal for the hose to clamp to) before eliminating it completely. In the mean-time, we are running a straight in-line fill tube until we get a new surge tank or have this one redone (the right way). Now we can keep the system together but we see these drastic temp spikes.

We'll be running at 170F (75C on gauge) or even cooler for 20 minutes, breathe on the throttle A LITTLE and it will spike (as fast as the gauge can move) to 260F (130C). Scary. Running it over and over (keeping foot out of it) and topping off coolant, now we're running pretty steady between 170 and 200. Must have gotten some air out of the system. But if you put your foot in it, that gauge just starts climbing again, slower now. Don't have the balls yet to see how far the gauge will go now. Would rather play it safe and make some improvements first.

Switching to a regular drive pulley as soon as it comes in the mail (next couple days), hoping that will fix, but seems like there's a lot of ground to make up considering how hot we get.

This is a dyno tested 508hp (flywheel) smallblock, and I know it will run warmer than bone stock, but I know there are others out there making even more power than this that aren't overheating.

Suggestions?

[John A. Simpson]

Am I wrong? Don't you need a thermostat or a restrictor to keep the water in the engine long enough to absorb some heat?

[Bart Carter]

Originally posted by John A. Simpson Am I wrong? Don't you need a thermostat or a restrictor to keep the water in the engine long enough to absorb some heat?

You need the thermostat so your engine will not run too cold.

Keeping the water in the engine for a certain length of time to "absorb heat" is old tech. Racers found out long ago that faster/cooler is actually more efficient.

[John A. Simpson]

So what do they sell restrictors for? I'm confused.

[MidOHasp]

I'm not sure if you are asking me about the stat, but if you were, yeah had a 195 stat in there that wouldn't open in a pot of boiling salt water (boiling temp probly ~230F) and replaced it with a 160 that is operational. Things are *okay* now but I don't like okay - can't light the tires in third when I'm driving like a sissy to keep the thing from boiling all the water out.

[Bart Carter]

Originally posted by John A. Simpson So what do they sell restrictors for? I'm confused.

Profit.

From Stewart Racing:

We strongly recommend NEVER using a restrictor: they decrease coolant flow and ultimately inhibit cooling.

For applications requiring a thermostat to keep the engine at operating temperature, we recommend using a Stewart/Robertshaw high flow thermostat. This thermostat does not restrict flow when open. The Stewart/ Robertshaw thermostat enhances the performance of the cooling system, using any style of water pump. However, the Stewart Stage 1 high-flow water pump may require this thermostat to operate properly, and Stewart Stage 2, 3, and 4 water pumps simply will NOT operate with a regular thermostat because these pumps have no internal bypasses.

Stewart further modifies its thermostat by machining three 3/16" bypass holes directly in the poppet valve, which allows some coolant to bypass the thermostat even when closed. This modification does result in the engine taking slightly longer to reach operating temperature in cold weather, but it allows the thermostat to function properly when using a high flow water pump at high engine RPM.

A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.

Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.

[Bart Carter]

When looking for a radiator/shroud combination, I needed to be sure that my choice would handle any horsepower I had. If you are thinking over 450 HP, you don't need to take a chance.

I went with the Ron Davis radiator from Levy Racing. These are custom designed for only Levy Racing to work in a FFR. They may be copied, but not duplicated in the quality and design. I felt the radiator was not an area to cut corners.

Maybe it is overkill, but I wanted the best.



(not my picture, but a Levy Racing-Ron Davis radiator)