[Squidward]

Making brackets to hang the fan. I didn't like the idea of using the thread-thru plastic ties to hold it in place. Good news is that the fan fits, with enough room to run factory shroud and a flex fan. Gonna roll these fans in series, see if I can get some insane air flow at idle. Or at least adequate.

[Squidward]

I should have used the plastic ties.

While mounting my fan brackets to the top of the radiator, I slipped with too much pressure on the drill and popped into one of the tubes underneath. Now I either get a new radiator, or I plug that tube. Angry with myself.

[JLMounce]

oof that sucks! Sorry to hear that. Any radiator repair shops locally that might be able to fix it?

[RocktimusPryme]

Originally Posted by Squidward

I should have used the plastic ties.

While mounting my fan brackets to the top of the radiator, I slipped with too much pressure on the drill and popped into one of the tubes underneath. Now I either get a new radiator, or I plug that tube. Angry with myself.

That does suck. If I opt to do the same thing I think I will cut the drill bit and mount it so its just a little stubby deal sticking out of the end of the drill that can only go so deep.

Im still in the middle of my PWM swap. Its been a bit dramatic. I got a new 600 Bosch motor for free, because the junkyard accidently wrecked the fan when removing it (2005 Volvo XC90). Was fine with me because I only needed the motor. ....... Then I cooked that new motor. 100% my fault. I didn't have 10 gauge black wire. So I used what I had, forgot I had red on the ground wire and put it in backwards. Dumb, unforced error, but these particular models do not tolerate being wired backwards at all even for a short time.

I bought another Volvo fan from a 2009 XC90 intended to swap the blade and motor into my SL500 shroud, which Volvo says are interchangeable from 2003-2014, but it appears that in 2007 they started using their own motor and not a bosch unit. I was initially annoyed but now Ive decided I might like the XC90 shroud more than the Mercedes SL500 one I had originally planned. So now I think Im just using the newly acquired fan and shroud.

They are both close, and both are about 4" deep. The volvo is slightly too tall, and the Mercedes is slightly too wide. Ive decided I would rather deal with too tall. But Im convinced either unit can be made to work, and would be even easier in a car with a slightly bigger radiator than a first gen.

The crazy part to me about the 2009 Volvo fan, is its open in the back. Which had me staring at it forever trying to figure out if they switched to a pusher fan, but no. Thats just how it is. There is a cage on the side that goes toward the radiator, but the exhaust side of the fan is wide open.

[Squidward]

Originally Posted by JLMounce

oof that sucks! Sorry to hear that. Any radiator repair shops locally that might be able to fix it?

Gonna look this weekend. I'm not ready to drop the $400-ish for a new rad. Pretty sure I only popped one tube, which represents maybe 1% or less of my total surface area. Maybe a rad shop can clean it out internally and plug the hole.

That does suck. If I opt to do the same thing I think I will cut the drill bit and mount it so its just a little stubby deal sticking out of the end of the drill that can only go so deep.

I'm sure I won't do that again, maybe use a step drill.

OK, I take that back. I'll be sure to do many more dumb things. It is my destiny.

Sorry to hear about your fan fiasco. I was scratching my head to hear you describe an open exhaust side of the fan. Weird.

In my exploring, I had come across the Volvo pwm, and it looked cool. I enjoy junkyard adaptations.

My ac clutch is slipping bad on my 04 GMC, and it is still so hot here. So that job just got bumped up in the que. Drove to work today at 5pm, no ac, windows down, 113 degrees. It reminded me of when I drove my 73 Formula as a daily driver from 1999 to 2007, no ac. A 64 oz Gatorade jug filled with ice water and stuffed under my shirt was my air conditioning. Sometimes you need some discomfort to make you appreciative.

[RocktimusPryme]

To give an idea, this is the back of both fans. The one with the yellow writing is the 2007+ Volvo fan and the other is the Mercedes fan.

That whole top area on the Volvo is blank plastic and will be removed. Both of these are basically the same size.

But it’s crazy to me that the back of the fan is open.

[Squidward]

Curious: Any idea of how much air they pull, and what kind of amp draw?

[RocktimusPryme]

Originally Posted by Squidward

Curious: Any idea of how much air they pull, and what kind of amp draw?

So the attachment below has information with the same motor, but a smaller 15” fan for a Volvo sedan. No flow numbers but it says highest amperage recorded was 42 amps.

The big 800 watt span fans in 6th gen Camaros are recorded over 5000 cfm in free air with roughly the same size fan as the one I’m using.

These are 600 watt motors. Given the blade is basically the same I would guess it’s at or slightly superior to the Lincoln Mark VIII fans just in a slimmer depth package with more control over the speed. Somewhere in the neighborhood of 4000 cfm. I should have one of them in one way or another this weekend.

[Squidward]

Nice flow. Also nice that it has a thinner profile.

[Squidward]

New radiator coming. Instead of drilling DOWN on the square channel brace to mount my fan brackets, I will mount the brackets with horizontal holes back to front.

[Shiny]

caca

hate it when that happens

[Squidward]

Originally Posted by Shiny

caca

hate it when that happens

Yeah. In years past I would've launched into a profanity saturated violent tirade. Thankfully that's not me these days!

[TedRamAirII]

Many Jeep Grand Cherokees, and Ram Trucks use a mechanical fan along with a electric fan. if you have the room, why not?. The design of them, allows good airflow when not turned on.

[JLMounce]

I've been researching Bernoulli's principal and looking at ideas for better ducting on these cars.

Basic idea is that air is lazy. REALLY FREAKING LAZY! Probably lazier than your 13 year old nephew.

The basic problem is that with these cars and how they are designed, it's a packaging nightmare that destroys the radiators efficiency because of the fact that air is lazy. Laymens like ourselves see a few sets of numbers or ideas and apply it when physics tells us something else needs to happen. Case in point is the front end design and access to fresh cool air. We might logically conclude that having as much grill opening to the radiator as possible is our best bet.

This is hurting us in actuality. For most of our cars the front end inlet sizes are larger and provides more air exposure to the face of the radiator than the area of that radiator face. Often, the entirety of the front end from the grill to the radiator core support is open. in many cases there are other openings from the core support area to the engine compartment that allow air to flow without passing through the radiator core.

Remember, air is freaking lazy and will take the easiest path it can find.

If we look at modern vehicles, many of them have very small grill openings and often there is specific ducting that is directing that air to the radiator. Based on Bernoulli's principle, in most cases the inlet should be somewhere around 1/3rd the area of the core. This reduces the velocity of the incoming air as the volume increases from the inlet to the core, creating high static pressure on the face of the core.

Without this ducting, we don't get nearly as much pressure increase at the core. The air just kind of tumbles around and looks for some other escape vector instead of through the dense radiator core. Having a radiator with lots of cores and lots of fins per inch actually makes this worse!

On the back side of the radiator, we want to create the opposite, a reduction in static pressure, but an increase in velocity. This acts in the same manner as scavenging does in your exhaust system. Basically making physics force air to stop being lazy and go through the radiator.

In many cases, we don't have room behind the radiator for proper ducting and we're using a puller fan (mechanical or electric) to do the job of increasing the air velocity. The next problem here is that the fan is slamming this column of air directly into the engine and from there into a hot engine compartment with little to no real venting taking place. This has the effect of creating pressure on the back side of the radiator, reducing mass air flow through the core/s. It also increases drag on the car itself. It's interesting to note here that Pontiac design engineers knew this and started implementing strategies on the 69 TA and in later TA's that had fender extractor vents. This not only aids in cooling, but decreases drag.

So, what can we do? On a first gen f-body specifically, the hood latch upright presents a massive space limitation for getting any real type of ducting to work here. I think you "could" model an inlet box that has a foil in it around the hood latch, but it would be pretty complicated. If this piece was removed entirely, there's plenty of space up front to have a proper air inlet mounted that seals to the core support. This would however require the removal of the hood latch and associated hood and valence modifications that would come with removing that piece.

Having one side of of the equation is still better than none of it.

But what can be done about the reverse side? From a ducting standpoint, probably not a lot, unless you move the engine back, or the core support forward. What you can do is provide cooling vents to the hood and fenders. While the placement of the 1969 Trans Am vents isn't optimal, the fact that it has a fairing over the actual vent creates a high pressure zone that sucks air from engine bay. Likewise if you added vents to the hood with gurney lips at the leading edge, you're also creating a high pressure zone that will relieve hot air from the engine bay.

I've observed this with my car in that with the hood open, I can't get the car to creep heat, even in upper 90 to 100 degree temps. That tells me just how much effect the hot underhood is having on my cooling system.

Now, all of this is a lot and for most people really overkill, unless you're doing the silver state classic.

Practically then, what can we do? We need to pay critical attention to the seal of the radiator against the core support as well as any passages from the front of the car through that core support. The more we do to seal the front end to force air through the core, the more efficient it's going to be. Even if not originally equipped, I also believe that the upper radiator close outs are not an optional piece (unless the hood seals to the core support) as well as the lower closeout that incorporates and air damn. That air damn is positioned on nominally the same plane as the back side of the radiator, and is creating some of that low pressure zone needed to help air move through the core.

We also have to take care that the radiator is sealed to never allow hot underhood air to circulate to the front of the core, further reducing cooling efficiency. Additionally, the shroud in use needs to "see" the entire core. In my case, I use the Flex-A-Lite black magic fan that is only 22" wide and 17" tall. For my factory sized radiator that is 23" wide and 16.5" tall, I end up with half an inch of exposure to the hot underhood air, instead of the fan drawing air through the radiator only, as well as 4.2% of the radiator that at a stand still, is doing precisely nothing, as it has no air flow at all across it. In fact, considering that the rear most tubes would be subject to hot air from the engine bay, it may actually be hurting things.

I've mentioned it before, but my one complaint about the Cold Case radiator is that it sits a bit more than an inch from the core support. That area is subject to the underhood air being drawn around to the front of the radiator, further reducing efficiency. These areas need sealed up a much as absolutely possible. In fact, I would go as far as to say that, I'd take the radiator off and clue foam around the back side of the core support where the radiator mounts, that way it completely seals off the engine bay to the core.

In my case at least I think there's a solid 5-8% efficiency increase to be had just with those items. But, I think that what I'm learning with some research and my observations is that what we think we should do to help keep these cars cool, can at times exacerbate the issue if we don't first take care of some of the minutia.

[RocktimusPryme]

So installed and working.

Good news.
2007?-2014 xc90 fan fits pretty will with minimal trimming. Wiring is easy and getting a negative polarity PWM signal out of the Holley EFI is pretty easy.

I let it just sit and idle for like 10 minutes at temp and it wouldn’t get past 182 on a hot day. And that’s only at about 60% duty cycle. Plenty of power left. I have it set to go to 80% if it gets to 190.

Bad News
We have reached the limits of my 78 amp 12si alternator. When I went for a drive it started to drop down below charging voltage at cruise RPM.

I thought I had a 94 amp but I found out I did not when I looked up the Carquest PN.

So a cs130 swap is in my very near future.

Overall a success though. I’m making a video. I’ll make a seperate thread with a full write up and post the video when I’m done.

[JLMounce]

Looks good! How does it do on the highway? Noticing any temp creep there? The fan is big enough that I doubt it is restricting flow at speed much.

[RocktimusPryme]

Originally Posted by JLMounce

Looks good! How does it do on the highway? Noticing any temp creep there? The fan is big enough that I doubt it is restricting flow at speed much.

The battery voltage gets out of hand pretty quick. I’ll have to get either a pumped up 12si or cs130 to install next weekend before I can get out there.

But I’m with you, it’s an 18.25” fan and it’s not a ton of blades. So I think it will be fine.

[Squidward]

Originally Posted by RocktimusPryme

The battery voltage gets out of hand pretty quick. I’ll have to get either a pumped up 12si or cs130 to install next weekend before I can get out there.

But I’m with you, it’s an 18.25” fan and it’s not a ton of blades. So I think it will be fine.

I run a CS130 I pulled from a yard, mid to late 80's, unknown make/.model.

Nice thing about a 60's accesory setup is that if you take off the rear alternator brace that attaches to the water neck, you can accommodate the slightly different spacing on the cs130. I also have one from a mid 80's Camaro that I have used.

I know these cs130's have bad reps with their bearing longevity due to small size, but there are bearing rebuild kits aplenty for cheap out there.

[Squidward]

Finished install of the Proform brushless 16" fan. I installed it as a puller on the radiator, in series with the nylon mechanical fan that Sirrotica recommended from his circle track days. I mounted the electric biased a little bit more toward the driver side so that the motor wasn't directly in line with the wp pulley/fan. Radiator is brand new 4 core Champion equivalent, so there should be little to no difference from that change.

I have it triggering off the FiTech at configurable on/off setpoints. I also can trigger it with a manual switch under the dash. The third trigger comes from the ac clutch power via a separate relay configured as an inverter so that everything is a ground trigger. I haven't hooked that up yet.

Fan turns on and off at all trigger temps, and works with the manual switch.

Last night I started up the car, put the AC on, and let it idle with 100 degrees ambient. Before, idling with AC on in similar ambient got me to 200 degrees quick and easy. It stayed at 176, fan running, until I got tired of watching it.

I will also do some more testing with enabling/disabling the electric fan to isolate cooling attributable to the electric fan.

[Squidward]

Here are pics. Wiring is functional, but needs some looming and cosmetic management. Pics also of series fan stack with factory shroud. I will also consider some air gap sealing too.