Advanced cooling design!

[Procharmo]

What denotes a radiators ability to cool and what percentage of cooling ability to the following attributes add.. The size and speed of fan(s).The air flow available. The size, material and number of cores.

My Porsche 911 has two 8"x10"x1" and a smaller 5"x20" centre radiator.
Do you think the two side radiators are connected in parallel and then the returns are fed into the centre radiator or the other way round!!!I'm not taking the Porsche apart. It's my daily driver and I can't afford the down time!
https://static1.pt-content.com/images/pt/2010/04/_2736-1.jpg

How much extra cooling is to be had by a separate engine oil cooler and transmission cooler? Could these extra coolers mean you could get away with smaller engine radiators?

I'm looking to design a cooling system for a twin Procharged 406 SBC which cannot have the radiators in the conventional location.
Much like the one below.
https://static1.pt-content.com/images/pt/2010/04/DSC_2154-1.jpg

But I cannot cut my frame rails and have twin Prochargers hence I cannot use radiators the same size as above.

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I did ask here before but It was deemed a cooling question. However I think the possible solution demands some physics and structured thinking with regard to air flow, fans, driving location etc...


I am considering adding a 3rd radiator above my blowers...
https://static1.pt-content.com/images/pt/2010/04/radiator_26x7x35_picture-1.jpg

[LSx_88_Ciera]

This may sound like an off the wall suggestion.
Look into coolers made for water cooling a computer. They are using some different tube design techniques with very high fin counts which increase cooling efficiency. I think you may be served well to run a combo of series and parallel, left and right in parallel and a series of smaller coolers on each side. Does anyone offer an over/under setup for the chargers vs the side by side setup.
I must say I am intrigued by your dilemma.

[Twentyover]

....
My Porsche 911 has two 8"x10"x1" and a smaller 5"x20" centre radiator.
Do you think the two side radiators are connected in parallel and then the returns are fed into the centre radiator or the other way round!!!I'm not taking the Porsche apart. It's my daily driver and I can't afford the down time!

Parallel. This presents the greated log mean temp difference to the incoming air yielding best cooling efficiency


.... How much extra cooling is to be had by a separate engine oil cooler and transmission cooler? Could these extra coolers mean you could get away with smaller engine radiators? .............

Additional cooling is available, the amount is dependent on how much heat the TOC is adding to the mix. Usually EOC and TOC's are placed in feont of the water radiator. If you're using the Porsche to tow a trailer up a grade, it will add more heat than if you're running on a level surface

[Procharmo]

Thanks guys. Good solid technical/scientific info... I'm going to go parallel and add the extra one above the blowers in series if needed.
It does pay to look at what OEM manufacurers did to package cooling into a small space for the 911 and adapt it to my Camaro dilema......Looking at the front of the Lambo Gallardo, Murci and Ferrari 360 and 430, twins must allow some space advantage over a large single and now that I know they are parallel I feel more at ease.
https://static1.pt-content.com/images/noimg.gif

When you want a deep comprehensive answer, you can do not better than come to the guru section!!!!
Cheers.

[Procharmo]

Just found a simple answer to this question buy comparing domestic hot water radiator systems to this dilemma.

https://static1.pt-content.com/images/noimg.gif

However I'm limited to -12AN hoses as I cannot find -16AN Y blocks..

[Rod]

why don't you design your own blocks? and have them machined? you can even do them yourself online with different companies like eMachineshop.com
(http://www.emachineshop.com/)
or instead of a Y use a T from RBS superchargers.com (http://www.rbssuperchargers.com/Page.cfm?startreturn=1948&MaxReturn=20&StartPage=1&InfoID=3921&Category1=New&Category2=All&Category3=All&Category4=All&Search=&Sortby=) has many different sizes

or just mill out an aluminum block and thread the AN fittings you want into it?
https://static1.pt-content.com/images/pt/2010/04/Junction-1.jpg

[MonzaRacer]

One big thing to think of is the coolant you use. check out Evans Cooling NPG+ 375F deg boiling point with no pressure, no corrosion issues and simply the best you can buy.
http://www.evanscooling.com/ or call 1-888-990-2665
Trust me this stuff WORKS.
Friend of mine has a V8 Monza with a 060 over 80 model 400 sbc, this thing ran hot in his truck with hug by large 4 core, but when strapped into his Monza, even with an aluminum replacement rad he couldnt stay under 240F deg. We pulled it out, cleaned everything and double checked heads/gaskets. Flush was ran through everything, and NPG+ installed,,,, run 195 on a 192 thermostat an d never goes over 210 ever.

[tonykim]

In OEM applications the cooling system is designed to handle all the heat loads generated by the thermal management systems. The design space is obviously the width and depth but also very importantly the amount of airflow available. This airflow estimate is based on the ability of a fan to either pull or push air through the cooling system with the vehicle or ducting restriction downstream. Typically the cooling system air side restriction is much smaller than the vehicle restriction behind it.

In practice what's typically done is that radiator core(s) and other auxiliary heat exchangers are sized based on the package space available and to match the heat rejection requirements on the internal cooling medium (water for the radiator circuit, air for a charged air system). Then the airside mass flow across the engine and vehicle operation range is estimated in a combination of experience from past vehicles, 2d simulations, and cfd analysis which use manufacturer fan curves adjusted for the restriction as installed. Just using a manufacturer's fan curve to estimate air flow often get's you nowhere. Each car, truck, or engine builder defines cooling design points (typically high hp or torque, high ambient, low vehicle speed) where the system must perform below certain top tank values. With that met everything else works.

Without simulation software for most people it's a process of trial and error. The most common mistakes people do are not having a correct blend of coolant or having a very deep radiator without proper fan shrouding or fan installation, too low a coolant flow, or poor baffling. Air is like electricity and it will take a path of least resistance. If you have a very thick radiator sitting in between large open gaps the air would prefer to bypass the cooling system and exit under fender wells or into the engine compartment. Large and deep radiators also require higher coolant flows so that the the localized fluid velocities get high enough to reach optimum heat transfer. Imagine the difference between pouring water from a waterhose into a bathtub or pushing it through a straw.

[Procharmo]

why don't you design your own blocks? and have them machined? you can even do them yourself online with different companies like eMachineshop.com
(http://www.emachineshop.com/)
or instead of a Y use a T from RBS superchargers.com (http://www.rbssuperchargers.com/Page.cfm?startreturn=1948&MaxReturn=20&StartPage=1&InfoID=3921&Category1=New&Category2=All&Category3=All&Category4=All&Search=&Sortby=) has many different sizes

or just mill out an aluminum block and thread the AN fittings you want into it?
https://static1.pt-content.com/images/pt/2010/04/Junction-1.jpg
Thanks, I found -16 AN and -20 AN Y fittings at Peterson fluid systems.

[Procharmo]

One big thing to think of is the coolant you use. check out Evans Cooling NPG+ 375F deg boiling point with no pressure, no corrosion issues and simply the best you can buy.
http://www.evanscooling.com/ or call 1-888-990-2665
Trust me this stuff WORKS.
Friend of mine has a V8 Monza with a 060 over 80 model 400 sbc, this thing ran hot in his truck with hug by large 4 core, but when strapped into his Monza, even with an aluminum replacement rad he couldnt stay under 240F deg. We pulled it out, cleaned everything and double checked heads/gaskets. Flush was ran through everything, and NPG+ installed,,,, run 195 on a 192 thermostat an d never goes over 210 ever.
Thanks for the info. It does look promising. I hope he can export to the UK!!!

[Procharmo]

In OEM applications the cooling system is designed to handle all the heat loads generated by the thermal management systems. The design space is obviously the width and depth but also very importantly the amount of airflow available. This airflow estimate is based on the ability of a fan to either pull or push air through the cooling system with the vehicle or ducting restriction downstream. Typically the cooling system air side restriction is much smaller than the vehicle restriction behind it.

In practice what's typically done is that radiator core(s) and other auxiliary heat exchangers are sized based on the package space available and to match the heat rejection requirements on the internal cooling medium (water for the radiator circuit, air for a charged air system). Then the airside mass flow across the engine and vehicle operation range is estimated in a combination of experience from past vehicles, 2d simulations, and cfd analysis which use manufacturer fan curves adjusted for the restriction as installed. Just using a manufacturer's fan curve to estimate air flow often get's you know where. Each car, truck, or engine builder defines cooling design points (typically high hp or torque, high ambient, low vehicle speed) where the system must perform below certain top tank values. With that met everything else works.

Without simulation software for most people it's a process of trial and error. The most comomon mistakes people do are not having a correct blend of coolant or having a very deep radiator without proper fan shrouding or fan installation, too low a coolant flow, or poor baffling. Air is like electricity and it will take a path of least resistance. If you have a very thick radiator sitting in between large open gaps the air would prefer to bypass the cooling system and exit under fender wells or into the engine compartment. Large and deep radiators also require higher coolant flows so that the the localized fluid velocities get high enough to reach optimum heat transfer. Imagine the difference between pouring water from a waterhose into a bathtub or pushing it through a straw.
Thanks again Kim,
I'll take all the points raised into consideration. The pair of radiators I have now will go in the car and we will see what does and doesn't work from there. Ducting may be constructed as well, if needed.

[tonykim]

If it was me I would run these radiators in parallel which I think is what you've decided. only problem with this is if you're still getting hot top tank temps it could be one side cooling better than the other and you'll have trouble figuring that out. also once you have the electric fans installed you may need to figure out a way to baffle around the area of the cores that isn't inside the fan radius. just come up with ideas. sometimes this is needed and sometimes not. often you'll get more ram air cooling (just air flow from vehicle speed with fans off) with some of the core not shrouded/baffled and not in the diameter of the fan.

also if you have other coolers like for the auto trans, power steering, a/c, etc. keep this out of the main air path to the radiators and try to use air coolers as much as possible.

also consider the option of running an electric water pump. if you can get some info from the radiator manufacturer about optimum coolant flow you can try to size your pump mass flow to get close to that. standard mechanical water pumps will increase mass flow with rpm and with smaller radiator surface area, even with lots of airflow you may find you have low rpm cooling issue. with an electric pump you get constant coolant flow all the time....just another thought.

[Procharmo]

Thanks for all the input on this thread. I will install the small radiators I have in parallel. I can get the hoses to be identical in length to equalise flow. I also have plenty of room to upgrade to a pair as large as 14.5" x 18" x 2.5" overall size if needed. The fan sits above the channel in the frame..
Made a start!!!
https://static1.pt-content.com/images/noimg.gif

One down one to go. (It's only the mock up!) Some bracketing, welding and tidying up is needed....

https://static1.pt-content.com/images/noimg.gif

But I guess it will all be worth it when I can get these in between the rads...

https://static1.pt-content.com/images/noimg.gif

[slownova73]

JEEEBUS! i cant wait to see the finished product... and hear it whistle at me!:1st:

[Procharmo]

Thanks, progress is slow but steady!

https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif

[beyonda68]

Love the pics. Great progress.

[Procharmo]

Thanks.

It idles and sits in central London traffic at 170 degs....I burnout then idle again with no great temp increase....I have the 3rd rad but have found no need to fit it yet. I'm waiting on a new carb as the old one didn't allow any significant boost before it went lean (1lbs). As soon as I get the dual needle quad inlet Carb shop beast installed I'll let you know how the cooling holds up when I take her up to 8000 rpm.................stationary!!

[beyonda68]

Wow looking at those tt the phrase that comes to my mind is that "size does matter"
:firefire:

[Pagani]

Love your new setup

[Procharmo]

It got to 200 degs today in rush hour traffic........ So I think it's time for the 3rd rad........

https://static1.pt-content.com/images/noimg.gif

After a few measurements and a quick template I bolted it to the rad support. I may put some rubber bushings on the bolts later.
Now I've just got to plumb it in series with the two parallel radiators.

https://static1.pt-content.com/images/noimg.gif

I will also have to move the power steering reservoir.

https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/noimg.gif

[67zo6Camaro]

Wow, that's some crazy sh*7^t. Love it. The tech info is great, I'm just in the process of moving my radiator from the front to the passenger seat in a Convt. Looking for weight reduction and weight balance for Autocross/track stuff. Working on aluminum boot set-up around driver area covering back seat and passenger seat area that will house the fan shroud set up.

Cheers
Brett

[Procharmo]

Wow, that's some crazy sh*7^t. Love it. The tech info is great, I'm just in the process of moving my radiator from the front to the passenger seat in a Convt. Looking for weight reduction and weight balance for Autocross/track stuff. Working on aluminum boot set-up around driver area covering back seat and passenger seat area that will house the fan shroud set up.

Cheers
Brett

Your project sounds involved. Wont you get hot with radiators inside the car? Is there enough room to put radiators under the car?

My original 355 with iron heads, intake, a Procharger P600B, stock brass/copper radiator, air con rad, Procharger 3 core intercooler and mild steel induction tubing was quite heavy.

I had to trim the front springs when I changed to ally heads, intake, water pump, power steering, Becool radiator, Procharger F1C and aluminium induction pipes. It gained about two inches.

Finally changing to a relocated battery, loosing the heavy intercooler, loosing the massive Becool radiator, shortening the induction pipes but adding a gear drive, extra blower and pair of light weight radiators actually raised
the ride height by around 3/4". So I figure the addition of this last radiator will have a limited impact on front rear weight balance.

You'd be surprised how much the stock front bracing brackets all weigh as well.

[67zo6Camaro]

Yep, when I put the standard front mount aluminum radiator in I was also surprized of the combined weight with fan and hoses etc. My car is around 3000 lbs dry (no driver or gas) and I just like playing with the numbers (weight to tire contact size). I have a full frame with adjustable coil-overs at all 4 corners, so ride height is not an issue. Car is currently used mostly for Autox and track so time in the car is limited and it's a full time roadster. The shroud set-up should move the hot air back away from me,,, but that remains to be tested. This will be set-up "B" for track use, I also have the original set-up "A" for street cruising with the seats back in the car for the family. I should be able to interchange between the 2 set-ups within a few hours.

Brett

[uxojerry]

Have you thought of using meth injection for it's engine cooling properties? There are other benefits but it may provide a little more cooling to supplement your modded radiators. One of the best systems is manufactured in the UK I think.

[MonzaRacer]

OK I am going to make a point,,,,200 degrees is NOT hot, and I have seen horsepower increases in engines when my customers would wanted to run at 14, 150,160 degrees, so I made a point of tuning several engines cold, and then started pulling them at higher temps and ever time we wind up with more power.
See the whole reason for people wanting cooler temps is NOT for power or any other reason but this,,,,water/coolant boils at 212deg F at sea level.
With this in mind THINK, the engine IS a heat production device,,,the engine USES heat to make power,,,so rejecting it to the atmosphere is ridiculous unless required like "in the olden days" because we had little ability to run our engines hotter,,,using the energy many reject to the air.
So many people mistake cooler as safer. With proper coolant such as the Evans NPG+ that doesnt boil like water at 212.
I have seen power increases of anywhere from 12 to 48 hp on raising the operating temps with proper coolant. With the advent of synthetic oils, few engines using Eagle Armor Coat components and oil coolers to maintain a proper mix of part cooling rather than having a complete engine at 140-150 coolant temps, use the heat to your advantage.
We had a 0.100 over 454, Eagle rotating assembly, AFR aluminum heads, thermal coatings keep combustion chamber heat in, Evans coolant and with identical engine as year before (owner sells old engine and rebuilds every season,,must be great to have sponsors!)And we picked up almost 40 hp and 30 lb ft of torque, it did use more fuel, but he couldnt be burnt down on line either. His rail had a Sirocco sized radiator with single core and 1 in tubes. We ran engine at 225 into bleach box and it never got to more than 240 by end of run on hottest day.
Air temps mattered little to the car and we had an alky guy try to burn him down. We had just switched to E85 as his fuel budget went up as his truck got stolen and totaled and insurance didnt leave him with enough to get another diesel so he got a gas GMC.
0.13 faster, oil never contaminates (no milky color) and the engine so far has shown NO wear or damage and we never had issues on gas OR E85. Oh and E85 got us another solid 0.10 in 1/8th.
I see so many people complaining when building $10k engines and then quibble over $200 in coolant AND benefit is you NEVER need pressure caps on system, so if it pushes coolant due to blown gaskets,,,you broke something.
Kind of cool.

Oh and cool car!