[JLMounce]

There's been a lot of cooling discussions here about shrouds, fans, radiators etc.

I decided recently I wanted to try one of Mike's shrouds after I started having some cooling issues with my previous setup.

That previous setup was a Cold Case CHC11 radiator with a Flex-a-Lite Black Magic 180 fan. This was all in front of a 580hp 465.

Full context, I did end up replacing the radiator with this change, so I can't give everything a 100% apples to apples comparison. My original CHC11 sprung two small leaks from the upper portion of the end tanks. Likely because I accidentally smacked the core with the engine when I was installing it last. I had cured that leak with a few Bars stop leak tablets, but ever since I did that, the system wouldn't cool as efficiently.

I finally hit 225 degrees in stop and go traffic in 90 degree weather and that was my impetuous to get this changed.

So what did I do? Basically, everything.

New CHC11 radiator from Cold Case
Fast Monty's dual 14" fan shroud
Dual Maradyne M142 fans
Big 3 wiring upgrade
Robert Shaw 180 degree stat
New AC Delco Upper and Lower hoses
New heater core hoses

My car with the previous setup has always run 195 on the highway, and would run about 205 in slow moving main street style cruising. In true stop and go traffic, or idling, it would slowly creep to 210 before leveling off.

With this new setup, also in 90+ degree heat, the engine now runs on the stat on the highway. In that slow moving main street cruise type situation, I observed nearly 15 degree cooling reduction, with the system running right at 190.

The idle creep is still there, but dramatically slowed. It now takes roughly 15 minutes of loaded idle time (in drive, on the brakes) to reach 210 degrees. If the car is put in park, it slows that time down even further. If the hood is opened, the fans pull the temps down to below fan off threshold of 183 degrees.

So, what is this telling me? By and large this radiator/fan/shroud combination is doing everything it's supposed to be doing. The hood open behavior leads me to believe I have a heat soak issue related to air under the hood. When the car is moving, even a little, the hot air is being evacuated. When stopped, it's building under the hood and finding place in front of the radiator to move, causing a loss of cooling efficiency.

Through a bit of research, it's also possible my water pump may be partly to blame. I am running a PRW aluminum performance pump with the 6" AC pulley. This pump is somewhat designed for higher rpm use and may give up some flow at idle and low engine speeds. It's designed to shine above 3500 rpm for sustained periods.

For my car that spends most of it's life cruising around, the Flowkooler may have been a better choice as it's designed around providing better low speed coolant flow.

I'm testing some additional idle RPM to see if that has any effect. I may look at other remediation measures such as hood vents as well.

Anyhow, I'm pretty stoked on this setup. The install looks nice as well compared to the old Flex-a-Lite fan which always kind of looked like an afterthought.