[Formulajones]

Originally Posted by dataway

Formula .... if it's cooling that good now ... actually might want to consider going to a 180 thermostat. Probably gain some engine efficiency ... and I bet with the increased heat transfer of 180 degree coolant it would be rock steady at 175-180 in the worst of conditions.

I see the secret to that SCJ cooling system right away. That no clutch mechanical fan looks like it's about 1/2" away from the radiator core, that's going to create a seriously powerful draw through the radiator.

Yep, 180-185 doesn't bother me a bit, so long as it stays there. The engine seemed to not complain during the times it was running 195 or more but it was nerve racking knowing this thing is built and tuned on the edge with 91 pump gas, and I've had engines that go from running fine to detonation city when the temps approach 200 degrees. So there is that concern.

May try it as an experiment in the future, as long as it holds that temp and doesn't creep. But I'm going to wait to pass judgement until we get into our 100+ degree temps here, and drive the 200 mile round trips to Phoenix for shows. If it passes that test I'll feel more comfortable. Those days are just about here. 96 degrees today at the house, and Phoenix is projecting 110+ today.

Yes the no clutch mechanical setup on the mustang is a factory SCJ piece, car also has a factory engine oil cooler on it. You're right, the fan is close. There is just enough room in there to work on the bolts for the fan but it's much easier if you pull the radiator out first.

[nmoreilly]

Originally Posted by HWYSTR455

Went thru this years ago with electric fans, only 2 setups actually worked well for me, the Flex-a-lite 4600 dual setup and the Derale dual powerpacks, both with shroud reliefs.

https://derale.com/product-footer/el...ual-powerpacks

It's not just the fan selection, or just the shroud selection, it's both.

So many advantages to running an electric fan, if you're not after an original look or build, there's no reason not to run electric fans. Just choose wisely.
.

What radiator did you use ? We put the car on the chassis dyno and ran from 2,000 - 4,500 RPM and the temp ran up quickly from 180-205. Currently has a 10 year old Rodney Red with dual SPAL fans and I'm wondering if it's a shroud / air flow issue. The build is a bit milder than formulajones car. Need a solution that will keep the car cooler and don't want to have fans on all the time.

http://forums.maxperformanceinc.com/...d.php?t=823250

[HWYSTR455]

They were champion radiators. If your radiator isn't clogged up, then don't swap it. Post a pick of the shroud and fans. May also want to make sure it doesn't want more timing, or look at the curve, that too can cause heat issues.

Most of the shroud 'kits' I see have the cheaper SPAL fans on them, so they can seem competitively priced. But the lower end SPAL fans don't flow much air, IMO they just sit there and spin, little airflow. If you look on the sticker on the fan, it should tell you which model it is.

Here is one of the 'nice' SPAL fans, MSRP is $170ea for a 12" fan, to give you an idea.

https://webstore.spalusa.com/en-us/p...-12-p-12v.aspx

Even if you get the pair at half price, you are still looking at $150 for just fans.

.

[nmoreilly]

Thanks

See Pictures

[HWYSTR455]

Yeah, those bird cage ones dont drawmuch air, and wo a shroud, it wont pull a lot across the core

[torqhead]

In my experience, the biggest issue other than fan speed/air movement is the assembly's that don't have a way for the air to move across the entire radiator. You would be surprised how much of an impact it makes when you add up all the "real estate" that the enclosed cover mask outside of the fan area. You would almost be better off just mounting the fans by themselves without the casing so when the car moves air flows...

[HWYSTR455]

Ah, i see the shroud,no reliefs tho. I suspect tho the fans dont draw a lot. Withem them on high, do you feel a draw from in front of the car thru the grills?

[nmoreilly]

Shroud depth 1-5/16....core to fan blade 2.

[HWYSTR455]

I will measure mine tonight for comparison

[Formulajones]

Been driving the car. Was pushing 100 degrees outside today. We buzzed down the highway for a good stretch. 3,000 rpm doing 60-ish and the engine ran 169 degrees and stayed there the entire trip. Temps even dropped from there once off the highway and cruising at less rpm. Can't complain for the size of this engine and the HP it makes. Things will get even better with a tighter converter and a little less rear gear.

Pretty sure dad is done with the electric fan idea, the factory clutch and shroud with this Cold Case radiator is kicking a$$.

[RocktimusPryme]

I bought one for myself at a show this weekend. They didn’t have it in hand so I gotta wait for shipping. I’ll let everyone know if my results are similar.

[Formulabruce]

Originally Posted by torqhead

All I'm going to say is anyone that takes a good look at that setup and thinks about it should realize the concept of cooling water through a radiator is airflow. When you block airflow over roughly almost half of the radiator undoubtedly you will lose cooling capacity.

Although the fans don't move as much as other options, I bet if you cut big ol holes in the metal areas of that shroud so air could pass through it would probably keep it a lot cooler. I'm sure that wasn't cheap, but sure looks to me like it was designed for looks versus proper cooling.

Excellent Post !

[Formulabruce]

Originally Posted by Formulajones

Been driving the car. Was pushing 100 degrees outside today. We buzzed down the highway for a good stretch. 3,000 rpm doing 60-ish and the engine ran 169 degrees and stayed there the entire trip. Temps even dropped from there once off the highway and cruising at less rpm. Can't complain for the size of this engine and the HP it makes. Things will get even better with a tighter converter and a little less rear gear.

Pretty sure dad is done with the electric fan idea, the factory clutch and shroud with this Cold Case radiator is kicking a$$.

Glad it worked out this way. Gm engineers Designed the shroud with many vacuum gauges in the outside cone to test the flow.
I find it odd that the "Engine masters" on Hot Rod TV took down their video on fan shrouds and fans and HP. They basically Proved that a Clutch fan is more efficient with HP and economy with its factory shroud. I am betting the aftermarket advertisers just hate that video.
While the new radiators have some great flow, you cannot forget science...
NOTE, Plastic IS mentioned Below ! .. its LAST hehe

[Formulajones]

While science is true and copper has better thermal properties than aluminum, I have never once been able to match temps with copper to what a good aluminum radiator does.

I guess they just don't make a decent efficient copper radiator?

Funny thing. We've run all kinds of copper in various cars here, 3 core, 4 core, desert coolers, high fin counts etc... And they do the job. But every single time I've swapped in a good 2 core aluminum the temps come down. Makes me wonder about science.

Couple cases of that. One is dad's GTO I started this thread about. Nothing has changed on the engine. With a high fin count 4 core copper and the stock shroud and clutch fan the engine would run 185 most days, and would push 190 if you ran the car on the highway extended periods, but would never get any hotter than that. Drove it that way for 2-3 years.
Swap in the Cold Case with their electric fan setup and that pretty much didn't change anything for the better, matter of fact made highway cruising at times a pinch worse. Once I took off the electric fans/shroud and reinstalled the stock shroud and fans, we are basically back to just changing a radiator and comparing temps from copper to aluminum. Suddenly now the car runs cooler than it ever has before with no other changes. We have yet to be able to get this thing past 170 degrees, and it's been 100 outside.

Another example is my chevelle. Same 4 core copper in that car, stock shroud and stock clutch fan. 185 pushing the car on a hot day was about as hot as it would get. It was never a problem. I simply switched to a Griffin radiator and changed nothing else. Now the car runs 165-ish on a hot day. Matter of fact I was driving it today following dad, 100 degrees outside, 3100 rpm to go 60 mph and mine never crept above 165 today. Nothing has changed on this engine in 15 years. Just the aluminum radiator dropped temps on this car a solid 20 degrees.

I've had similar results with my firebird as well.

Kind of odd when you look at the science end of it. I believe it's the better design of the aluminum that contributes. 2 cores that are 1 1/4" wide rather than having 3 or 4 small cores of 1/2" or less. Because by the time the air passes through the first 2 cores, the air is heated and isn't doing much of anything for the last 1 or 2 rows. This is also the reason why I avoid even aluminum radiators that have more than 2 cores. It's better to have 2 big cores rather than 4 small ones.

[Formulabruce]

Surface area of the actual Aluminum Big cores.( not the fins) More air flow in volume.( less "cores") . If copper radiators were built that way.. WOOAH....

[torqhead]

Originally Posted by Formulajones

Kind of odd when you look at the science end of it. I believe it's the better design of the aluminum that contributes. 2 cores that are 1 1/4" wide rather than having 3 or 4 small cores of 1/2" or less. Because by the time the air passes through the first 2 cores, the air is heated and isn't doing much of anything for the last 1 or 2 rows. This is also the reason why I avoid even aluminum radiators that have more than 2 cores. It's better to have 2 big cores rather than 4 small ones.

Interesting, I've got a 4 row aluminum. Runs fine, have you ran a test to compare the 4 versus 2 aluminum?

[JLMounce]

Biggest issue with the brass radiators is how they are constructed. while copper does transfer heat better, the fins are brazed to the tubes with a solder material that does not. So a good portion of the heat transfer ability is lost in how the unit is constructed.

[Formulajones]

Originally Posted by torqhead

Interesting, I've got a 4 row aluminum. Runs fine, have you ran a test to compare the 4 versus 2 aluminum?

Yes I ran a 4 row aluminum years back (champion) and my experience with that was not good at all to say the least. That one would temp creep always and never stop. As long as I was moving I was safe, but any long period idling had the temps climb and never seemed to find a peak. I would shut it down at 230 as it was still climbing. That wasn't the only problem I had with it but long story. Granted I had to idle for periods of a 1/2 hour or more to see this situation but there were a couple instances I ended up pulling over and shutting it off to cool down.

After talking to people like Ron Davis it was explained to me that more rows aren't the answer as the more you have the less heat is transferred due to heating of the air. Larger tubes and less rows work better. While you may find a 4 row aluminum or even a 3 row, can do the job and work fine in a lot of applications, the 2 row with very large tubes is more efficient and pretty much how most of the big radiator companies do it these days. Talking with Griffin they stick pretty much to 2 rows and just change the tube size depending on the HP or the cooling capacity you're looking for.

That's what impressed me about the Cold Case. It has 1.25" tubes. My Griffin in the Chevelle is the same, and I already knew how well it worked cooling a 600hp BBC with A/C Talking with them years back they told me they would even build a single row with one large tube if needed. The larger the tube the more surface area to dissipate the heat. Anyway I was pretty sure at that point the Cold Case would work well, and in dad's instance with 571 cubes and 724 hp, he had a lot of naysayers that told him there is no way he would keep it cool on the street and he was crazy. Well, the darn thing is running cooler than my little 454 chevelle now LOL

Just throwing this stuff out there. You guys are welcome to do what works for you.

[Formulajones]

Originally Posted by JLMounce

Biggest issue with the brass radiators is how they are constructed. while copper does transfer heat better, the fins are brazed to the tubes with a solder material that does not. So a good portion of the heat transfer ability is lost in how the unit is constructed.

That's along the same lines I was thinking. It's the construction that inhibits the copper radiators ability to cool better.

[64speed]

My Tempest has the small core support that only takes a 15 inch radiator. I just saw where cold case was offering the HO radiators in that size with the 1 1/4 tubes. I swapped it with them and other than it using a 1966 upper radiator hose the swap is direct. It will be a long time before I find out but I hope it will cool my beast.