[AdamIsAdam]

Update: temps 82°. Straight highway for 60 miles and the highest it got was about 187° and it came down to 180° around town.

The Mechanical fan kicks on it about 179°. I can hear it. So far I'll very pleased.

Still no fan shroud.
160° T-stat

http://s300.photobucket.com/user/ada...82610.mp4.html

[68 Firebird]

Good Job.
May sound funny but had mine yesterday and wife noticed console was cool
And not warm. Also using the 160.
Keep at it!!!!
Gerry

[Jim Doran]

Glad you guys are making progress, but my .02

If you have a 160 t-stat and you are running 180+, your cooling system is NOT actively managing your temp. It will only be a matter of time before the circumstances cause you to go north of 200+;

The t-stat only sets the MINIMUM temp. If you are running at the t-stat setting, then all is good and your radiator and t-stat are working against each other which is the desired state. If you are running 180+ on a 160 t-stat you would run cooler WITHOUT the t-stat as the only function it is performing is a restriction.

I realize back in the day blah blah

[AdamIsAdam]

Yea, I understand that. I guess it's a matter of how good i want the system and how much time, money and effort I'm willing to throw at it.

What's interesting about my car is that the engine seems to run hottest on the highway. Today will be pretty hot and I plan to drive it a lot, NOT on the highway to see what my maximums are.

[Jim Doran]

Adam, I had the same exact problem on the highway. Griffin AL radiator that appears 100% stock solved it. Not cheap, but looks great and functions great.

Understand your on top of it.

For comparison, the new 2016 Camaro has 3 separate radiators !

[AdamIsAdam]

Originally Posted by Jim Doran

Adam, I had the same exact problem on the highway. Griffin AL radiator that appears 100% stock solved it. Not cheap, but looks great and functions great.

Understand your on top of it.

For comparison, the new 2016 Camaro has 3 separate radiators !

Which Griffin AL radiator did you go with?

I have an aluminum radiator, but don't know the kind. I like it based on the looks and all, but it's the wrong one for the year.

Griffin:

(http://www.griffinrad.com/load_detai...key_id=6-00156)

Par tNumber: 6-00156
Year/Make/Model: 64 Pontiac GTO
Core Size: 15X25.5X2.68
Tube Size: 1.25
Number of Rows: 2
Outlets: TR - 1.5"/BR - 1.75"
Additional Information: Early Pontiac V8
Note: Right Side Filler (passenger)

[Jim Doran]

You have the right link for the 64;

Here is the one for the 65 that I have;
http://www.griffinrad.com/load_detai...key_id=6-00156

[AdamIsAdam]

Originally Posted by AdamIsAdam

...
What's interesting about my car is that the engine seems to run hottest on the highway. Today will be pretty hot and I plan to drive it a lot, NOT on the highway to see what my maximums are.

I forgot to mention that yesterday I did about 30 miles in high 80s, all around town, and the temps were always at 180° while moving and when idling for extended periods they were 187°.

For a car that was routinely running 200-210° I'm pretty happy thus far.

I have a 19.5" fan that I can install rather than my 18.5" so i will toss that on there.

If I ever decide to upgrade further, I'll do a new radiator and then install the fan shroud I have, which is why I don't want to hack it up now.

[AdamIsAdam]

I can't remember if we linked this Engine Masters cooling fan HP dyno session before. It's great to watch. Unfortunately, the factory fan robs about 30hp as shown at this point:

https://youtu.be/ZXdLgaFXZzs?t=12m23s

And then they get back 8hp by ditching the shroud (which is how my setup is now since it runs cool without a shroud):

https://youtu.be/ZXdLgaFXZzs?t=14m23s

[lust4speed]

Can't think of any Pontiac performance engines after the mid 60's that came with what the Engine Master guys called the "stock fan" that caused the 30 horsepower loss. The clutch fan's 14 horsepower loss sounds about right.

The shroud would cost horsepower because it does what it is supposed to do - help the fan pull more air through the radiator. More air pulled requires additional horsepower, but it accomplishes why we have the fan in the first place which is to draw more cooling air past the radiator fins.

My non-air '67 HO did not come with a shroud, but was less than two weeks old when I went down to the dealership and purchased one to combat the temps I was seeing when stuck in summer traffic. While it dropped idle temps down by close to 20°, it did raise running temps blasting down the freeway by about 5°.

They didn't mention that the flow of air going through the radiator at speed would greatly reduce horsepower loss from the fan since it would be at or close to a neutral pull.