[AdamIsAdam]

WHAT THE HECK RADIATOR DO I GET? I'll start reading more. I'm sure this question is almost as heated as "what oil should I use?"

http://www.hotrod.com/how-to/engine/...-for-your-car/

[AdamIsAdam]

I confirmed that my water pump pulley is 6" and crank pulley is about 8"

Still awaiting ET times!

[FrankieT/A]

Above 30 MPH you don't even need fan. Your looking in the wrong place. Aluminum radiator yes, clearance the water pump yes. Operational and dialed in vacuum advance yes. The fan is not going to change a thing at 60-70 MPH and 3000 RPM. You are experiencing normal Pontiac temperature creep at 3000 RPM and above. Start thinking about an OD tranny. 3000 RPM on the highway is a miserable experience. I've done a lot of things to a lot of cars over 3 decades, best thing I ever did to any one of them was Over Drive. Followed by Four Wheel Disc running a close second. All Pontiac woes go away with OD. Old Pontiac buddie saw me on the highway once cruising for a long time at 80 MPH with the windows up and A/C on. The next time he saw me he told me "it was weird seeing an old Pontiac tooling along like that!"
I bet if you drive around all day never going above 2000 RPM your temp never goes up. Now imagine doing 75 MPH at 2000 RPM. Just my opinion....

[Lee]

A mechanical is NOT going to offer more cooling than a proper electrical fan - not at the engine speeds where you NEED the most cooling, at lower speeds or idling.

A GOOD electric fan, with proper shrouding, will flow over 3000cfm at ANY time. At idle, a mechanical will only flow a fraction of that.

On my old 469" Firebird, it ran MUCH cooler after adding an electric water pump and an shrouded Black Magic fan. It also dropped nearly a tenth in e.t., and gained a solid MPH in trap speed.

The same car, when I had the mechanical pump and fan, once had the fan belt break on the highway. With the belt OFF, the airflow through the radiator was enough to keep the radiator cool. The airflow also spun the fan (no clutch, a flex fan mounted directly to the pump) fast enough to keep the water circulating through the motor. I was able to drive about 15 miles down the highway without over heating.

My Falcon wagon had a rather small opening for a radiator, and a 620hp stroked small block - less than half the radiator surface area that I had with the Firebird. The factory radiator was NOT up to the task. I worked with C&R Racing, and they developed a 2-pass aluminum radiator, aluminum shroud and a 3000cfm SPAL electric fan. I had a Meziere electric water pump, and used a DC Controls PWM controller which was designed to control both the pump AND fan at variable speeds. DC Controls also provided cool "indicator" lights I mounted on my dash - they turn on ONLY when the motors (one for the fan, another for the pump) are actually running, the color varies with the motor speed, and if the motor stops the light goes off (a warning system). I drove that car in 100+ temps, and it never overheated.

There are some 3-pass radiators out there for GM's, one of those would be a good choice.

Use the largest shroud, highest CFM fan you find, and do your best to have the shroud cover the entire fin area of the radiator.

Control the fan with a DC Controls PWM controller, and use the indicator lamp to KNOW that the fan is running.

[JSPONT]

The last 2 post are correct. I have a fan controller, you can turn a knob to have the fan come on at any temp. I have mine set at 180. An led light lets me know its on. When I cruise down the highway now, it will actually shut off for a while, turn on a little, shut off... So you have to look and see whats wrong by elimination. You have a new pump, clearanced I hope, tune and timing good, proper thermostat, after that its a radiator.
Isn't hot rodding fun! LOL

[Chicagogoat]

Years ago on another forum, Lee suggested that I use the DC control for my electric cooling setup and it was really excellent advice! Before I used typical stuff to control the fan a Flexalite 15" Black Magic fan and their variable speed control which sucks big-time! Then the CSR WP was just powered by a simple calling relay.

DC controls make a few different controls for different applications. As Lee mentioned the one we use controls both fan and WP with one sensor and variable speed is extremely efficient and reliable as heck with 4 years so far all street driven and just a few track outings. It soft starts both fan & pump on start up then ramps up the power to constantly match the load for consistent temps. Again, key here is a high capacity aftermarket radiator and high output fan rated above 3000 cfm. The WP you decide to use is irrelevant. The CSR I run flows less than the Mezeire I believe and has a tiny impeller compared to the good cast one on the mechanical pumps.

Another point about shrouded electric fans that I don't see discussed at all is their tendency to limit airflow thru the core at highway speeds. That shroud with the tightly fitted fan acts the same as a funnel that can overflow with too much coming in. That's why if you noticed the larger dual fan setups have trap doors that open up at high speeds maximizing flow thru the core when you need it most. As I stated before the Black Magic fan consists of a 15" fan and a decent sized shroud to cover most of the core for excellent cooling at low speeds. The rest of the core say 20% or so gets enough airflow bleeding thru at high speeds. This is an excellent fan for a setup under 550HP is my recommendation. It's rated at 3300 cfm and draws about 20 amps. Be prepared to beef up your wiring and upgrade that alternator.

[John62]

When you say DC Controls, are you talking about Delta Current Control or some other brand. I use the Dakota Digital controller to control two 13" fans and it is fully programmable and has worked great for a few years now. I don't see how a fan that draws 20 amps will ever pull more than about 2100 cfm.
The rated CFM is highly subjective and is not always accurate. Think of the current draw rating like a
horsepower rating. The higher the current rating the more powerfull the fan will be. Regardless of the rated CFM.

[Chicagogoat]

Originally Posted by John62

When you say DC Controls, are you talking about Delta Current Control or some other brand. I use the Dakota Digital controller to control two 13" fans and it is fully programmable and has worked great for a few years now. I don't see how a fan that draws 20 amps will ever pull more than about 2100 cfm.
The rated CFM is highly subjective and is not always accurate. Think of the current draw rating like a
horsepower rating. The higher the current rating the more powerfull the fan will be. Regardless of the rated CFM.

Yes that's it.http://www.dccontrol.com/constant_te...ontrollers.htm

The popular flexalite black magic fan is rated (supposedly) @3300 cfm.
It's rated at 18 amp draw. But I do recall having the amp probe on it after putting the new control on and it was drawing over 20 amps. The CSR pump was pulling like 10 or so. http://m.summitracing.com/parts/flx-188

[John62]

The black magic does look like a nice piece. I wonder if we are getting off base here. His problem is at highway speed, above 3000 rpm. Electric fans on new cars are designed to shut off at 45-50mph. At highway speed he should need no fan at all. So saying that back to basics, Good water pump, good impeller, tight clearance I like the high flow tstat 180 deg., take the kink out of the upper hose, [see pictures in original post] and a good radiator, aluminum with 2 rows of 1.25 cores from Griffin or Mark7, or a copper 4 row with tigher rows of cores like US Radiator makes. Then a fan and shroud. I wonder if that upper hose is higher then the filler neck and trapping air, slowing water flow? The filler neck should be the highest point.

[AdamIsAdam]

So many opinions and directions!

Originally Posted by John62

The black magic does look like a nice piece. I wonder if we are getting off base here. His problem is at highway speed, above 3000 rpm. Electric fans on new cars are designed to shut off at 45-50mph. At highway speed he should need no fan at all. So saying that back to basics, Good water pump, good impeller, tight clearance I like the high flow tstat 180 deg., take the kink out of the upper hose, [see pictures in original post] and a good radiator, aluminum with 2 rows of 1.25 cores from Griffin or Mark7, or a copper 4 row with tigher rows of cores like US Radiator makes. Then a fan and shroud. I wonder if that upper hose is higher then the filler neck and trapping air, slowing water flow? The filler neck should be the highest point.

John, Chicagogoat, etc
You are correct on a few things and some other items need clarification:

- I don't have a new water pump. (Does that just unbolt without taking timing cover off?) It's got newer bolts, so I assume it was at least off at some point since the engine was built in 2012. I will eventually take it off and check clearances.

- upper rad hose gets fully inflated when the car is running, so that kink is gone. However, with that water neck, the hose is higher than the radiator. I have new filler neck to be installed when I drain the system. Also, I have a home made spring in the lower rad hose.

- My Taurus fan shroud I could see being a funnel and blocking airflow. I did do this one test: as I drove at 3,000 on the highway, I turned off my fan. Temps went from 200 to 210. I turned the fan back on high, and they went back to 205 or so. That doesn't totally address the funnel issue, but it says that the fan pulls more CFM running than not running at highway speeds because of that shroud.

- So, electric or manual fan setup? I do combined city/highway with this car, and the temps are bad on the highway. Not sure the answer. I like the electric fan setup, the idea of having full cfm during low speed cruises and parking lot driving, etc. but don't want temps at 200+ and would like to be able to make longer trips.

- Radiator: How do I ID what radiator I have? I don't see any markings on it. I do like the shape of it. Plus the top makes for a very handy tool holder when working on it! (don't discount that, it's really that handy; plus I don't scratch my newly painted engine bay)

- Cliff and others with vast pontiac experience say go manual fan. That says a lot.

I'm wondering how I know if my radiator is part of the problem or not. How do I know? Just trial and error? That gets expensive. (And WHICH FREAKING RADIATOR? SO MANY THEORIES!)

So what's the first thing to try?

[60man]

FWIW a triple bypass radiator has the hose inlet/outlet on opposite sides.
I bought one off EBay for $230.00 IIR. My motor ran too warm for me so I went with Flo-Cooler pump and the triple bypass radiator and all is well now with stock clutch fan.
Dumped electric fan.
This is in my 60 X race car/Ventura

[AdamIsAdam]

Does that mean my radiator is a triple bypass because the hoses are opposite sides?

Originally Posted by AdamIsAdam

[tom s]

Have you got a lazer temp gun?If so check the water temp when it goes into the radiator and when it goes out.Know how much temps drop.You can also check temps at diff parts on the engine like thermo housing,xover,head etc.Tom

[Jim Doran]

- My Taurus fan shroud I could see being a funnel and blocking airflow. I did do this one test: as I drove at 3,000 on the highway, I turned off my fan. Temps went from 200 to 210. I turned the fan back on high, and they went back to 205 or so. That doesn't totally address the funnel issue, but it says that the fan pulls more CFM running than not running at highway speeds because of that shroud.

It is possible that by turning on the electric fan with the current shroud setup, that all it is doing is reducing the funnel & blockage effect caused by the current setup. It is helping to evacuate the high pressure air held up in front of the shroud.

An interesting experiment would be to remove the shroud if possible and go for a highway drive.

[AdamIsAdam]

Originally Posted by tom s

Have you got a lazer temp gun?If so check the water temp when it goes into the radiator and when it goes out.Know how much temps drop.You can also check temps at diff parts on the engine like thermo housing,xover,head etc.Tom

Yup, got those numbers. With car hot, around 200° or so based on my electric gauge reading from intake crossover, the laser says temp on the upper radiator hose near radiator is 190° and on lower hose near radiator is 160°. I would think a 30° at idle with electric fan running means the radiator and fan is doing a decent job, right?

The fan shroud is pretty restrictive as I examine it, so I can see why it gets hotter at highway speed with fan off.

Next question: I have the 15.5" radiator support, but my core is 18" tall. How? What shroud will fit?

[tom s]

What does the lazer say at the temp sender?Is your gauge accurate?I hate elect gauges.Tom

[AdamIsAdam]

Originally Posted by tom s

What does the lazer say at the temp sender?Is your gauge accurate?I hate elect gauges.Tom

I found my notes from when I took these readings. Gauge in the car said 210. Laser pointer at crossover said 209. 190 and 160 were as I said before.

[Squidward]

Originally Posted by AdamIsAdam

Squid,
Thanks for the detailed reply, but you left out the most important detail: WHAT ET DID YOU RUN?

Seriously, I may make this a winter project and convert over to a mechanical fan. Debating just going all out and putting a new radiator in or doing this I stages.

My water pump pulley is about 6". I think my crank pulley is 8" but I have to check my notes later.

Embarassed to post it! 14.9... 0.6 sec slower than my last one. New carb, not dialed in yet. I'll get it, tho. This car has easy 13's in it, will try to squeeze 12's when I get my deeper gears in.

[AdamIsAdam]

Originally Posted by Squidward

Embarassed to post it! 14.9... 0.6 sec slower than my last one. New carb, not dialed in yet. I'll get it, tho. This car has easy 13's in it, will try to squeeze 12's when I get my deeper gears in.

Don't be embarrassed. I took my 68 LeMans to the track for a big Stock Appearing drags event. It was very hot/humid (excuses already) and I only ran 15.39. HOWEVER, I ran 15.39 ALL DAY LONG! I dialed in at 15.38 and advanced all 8 rounds to take the full event, winning by .011! (I was cutting REALLY good lights too ;-)) I even started to calm down enough to step on the brakes when the other guy spun the tires so I wouldn't break out (hence the 15.55 run).

I got two nice trophies and was featured in several magazines! Time of my life. Oh, and because it was my first return to the track in 20 years, that 15 seconds was the most exciting 15 in a long time!

Watch the day here:

[AdamIsAdam]

Update: I FINALLY had some free time when it wasn't raining to take the car out for a spin. I wanted to drive only around town and stay off the highway just to gather data.

Results: after 45 minutes and never going at highway speeds, covering 16 miles. It's 65° out side.

Car never got over 190-195°. Mostly around 185°.

So, what does this tell us?

I'm thinking the easier change to make is to revert to a clutch fan and shroud.