65 GTO High Efficiency Radiator
 

Has anyone purchased one of these radiators from Ames? I purchased one for my one owner original 65 GTO. The first thing I noticed, the ears on the radiator cap were not aligned parallel with the radiator like my original radiator. Also, it had a lot of white residue inside. I also did not see any improvement in cooling. Am I doing something wrong?

As far as the cooling ... could be any one of half a dozen things causing problems instead of the radiator, so hard to tell.

High Efficiency radiator
 

I wish someone could offer some suggestions that I haven't tried yet. The heating problem occurs when driving on the freeway at a cruising RPM of about 3,000 at 75 deg air temp for about 20 miles or greater. I have done the following:

1. Installed SS spacer plates in the front cover.
2. Changed three different water pumps with different impeller configurations.
3. Re-gapped the spacer plate to the water pump impeller from .187 to .080-in.
4. Purchased a new fan clutch.
5. Installed a temperature gauge in the radiator outlet hose to monitor cooling across the radiator.
6. Added a fan shroud.
7. Flushed the cooling system with muriatic acid.
8. Flushed the cooling system with plain water and bursts of compressed air.
9. Changed from an anti-freeze to a water-wetter solution.
10. Made an adapter to solid mount the original aluminum 7-blade fan.
11. Checked the thermostat in hot water for proper opening temperature.
12. Tried putting two different size orifices at the radiator inlet, 3/8 and 1/2-in.
13. Checked the intake manifold temperature sending unit for proper output.

Uttergto ... I would suggest posting this in the heating and cooling section, you will get WAY more responses.

Had similar problem. Tried everything you tried. Solution was to reduce RPM. Installed AOD and problem completely disappeared. Never runs hot at highway speed any more. Take it for what it's worth. Good luck.

I had a cooling problem that I couldn't figure out. This was a motor that had been rebuilt prior to my ownership. The motor was clean and ran good. It wasn't until a frost plug started leaking that I found the problem. Once I removed the frost plug. I found that the block was full of rusty crud. Whoever rebuilt it, never replaced the frost plugs or cleaned the block.

What radiator did you purchase from Ames? They carry several brands and models.
Also, what is your water pump pulley to crank pulley ratio. You want to overdrive your WP pulley for better pressure.

Do you have the spring in the lower radiator hose to keep it from collapsing at high RPM?

Yes I have the spring in the lower hose.

I believe the radiator is from US Radiator. It has the original pulleys on the harmonic balancer and water pump.

The block was completely cleaned with the plugs out.

What is AOD?

Found a Heating and Cooling title, but could not open it.

Another thing I dislike about the radiator is the cap orientation, it is not parallel to the radiator like the original. I am going back to my original radiator, because I see no improvement in cooling.

Found a Heating and Cooling title, but could not open it.

Needs a good tune , timing & fuel will correct most hot runs.

A two row aluminum radiator with one inch or larger tubes will outperform a three or four row radiator by a wide margin. Your radiator is inadequate.

Don

High Efficiency radiator
 

The problem with this is this is a one-owner, numbers matching original 1965 GTO. An aluminum radiator with extra fans would look out of place.

You could paint it black. Additional fans should not be needed.

Don

High Efficiency radiator
 

I have already wasted about $700.00 on a radiator with a cap that is not oriented parallel to the radiator, supposedly for a 1965 GTO. I have questioned Ames Performance about this several times with no answer. Rather frustrating, I guess I didn't know what questions to ask before the purchase, but you would think the cap orientation is so obvious that it would be correct.

I've had good luck with re-cored original radiators. Not cheap to have done though. I figure if they were good enough for the originals they should still be good enough.

You didn't mention any temps ... so not sure what you might be considering too hot, or good. Bear in mind the smallish OEM radiators used in 65 required suitable temperature difference between air and coolant to work properly, so running a thermostat of the same rating as OEM would be important.

Meaning it's quite possible the OEM size radiator is not capable of maintaining the temp you desire, but is able to maintain whatever the OEM spec for temp is.

If your system does not maintain the OEM specified temp, THEN you have a "problem" ... if your system does not maintain 160 or 170 degrees you may NOT have a problem, you just have a system that was not designed to run at that low a temperature.

These are things I have done and checked. I am running a 180 deg. thermostat, the radiator has been re-corded and has been checked for flow. After driving on the freeway at about 3,000 RPM for 15 miles on an 80 deg day, the radiator inlet temperature is about 215, and the outlet temperature is about 205. As soon as I get on surface streets, the inlet temperature drops back to 185, and the outlet temperature is about 170. I am using 93 octane gas spiked with VP C12 (108 octane) with 6 deg initial advance in the distributor, factory specs.
1. Installed SS spacer plates in the front cover.
2. Changed three different water pumps with different impeller configurations.
3. Re-gapped the spacer plate to the water pump impeller from .187 to .080-in.
4. Purchased a new fan clutch.
5. Installed a temperature gauge in the radiator outlet hose to monitor cooling across the radiator.
6. Added a fan shroud.
7. Flushed the cooling system with muriatic acid.
8. Flushed the cooling system with plain water and bursts of compressed air.
9. Changed from an anti-freeze to a water-wetter solution.
10. Made an adapter to solid mount the original aluminum 7-blade fan.
11. Checked the thermostat in hot water for proper opening temperature.
12. Tried putting two different size orifices at the radiator inlet, 3/8 and 1/2-in.
13. Checked the intake manifold temperature sending unit for proper output.

What was the purposes of the orifices in the radiator inlet? Never fall for the old "the water isn't staying inside the radiator long enough to cool" myth ... that's not how thermodynamics work.

So you have about a 15 F delta/T between inlet and out of the radiator off the freeway ... I wonder what the factor spec for temp drop through the radiator is.

At freeway speeds your delta/T drops to 10 degrees F ... which would indicate to me a lack of air flow (unusual at highway speeds), or some situation with the engine where it is producing an inordinate amount of heat at 3000 rpm.

If it was a coolant flow issue you should see a large delta T inlet/outlet at highway speed as you would have an plenty of air flow, but less than optimal coolant flow.

What type of shroud did you add? Shrouds are good at pulling more air at low mph but the wrong one can hinder air flow at high speeds. The later model factory shrouds had an important taper from radiator to fan opening that did a good job pulling air through the WHOLE radiator rather than the area directly in front of the fan. Fan depth inside the shroud opening is also very important.

Pictures would be a great help. Lots of time experience guys can look at your setup and spot something.

High Efficiency radiator
 

Everything is factory original except for the fan shroud; it is a plastic shroud from Ames. Driving on the freeway, the outlet temperature approaches the inlet temperature, and that's when I exit.
I am familiar with the equation Q=mCp delta T, where Q=heat transfer rate, m=mass flow rate, Cp=specific heat, and delta T= change in temperature. As the delta T approaches zero, the heat transfer rate also approaches zero.
I thought that eliminating the fan clutch and direct driving the factory aluminum 7-blade fan would help, but not much help. Next, I will tape a piece of yarn to a welding rod and check the airflow around the radiator. I guess I could try eliminating the fan shroud. I don't know how to insert photos.

Thanks, Rowland

Just looked at the Ames fan shroud ... appears to indicate it as a replica of an OEM part so I wouldn't think it would be a big problem.

Engine is stock?

There are those here that say lean mixtures etc. can increase temps at speed ... might want to start looking at something like that. I'm not very knowledgeable about that ... maybe someone will chime in.

High Efficiency radiator
 

The engine is stock .030 overbore with a Ram Air 3 cam. Maybe I will pull the spark plugs and look at them. I don't detect any pinging sounds.

Uttergto, the last time we spoke I was under the understanding that any discrepancies or questions were cleared up. I apologize if that was not the case. Before this thread was started we spoke about the cap orientation as well as the cooling abilities of the radiator. I understand that your original cap is parallel to the radiator, which some are. We have also seen the caps on original radiators rotated diagonally like the one you have received. This is something that none of us have an answer for; many things have been done on the Pontiac/Harrison assembly line without any rhyme or reason. As far as the cooling is considered, many of the members posting here have some good points; usually it is not the radiator, but one of the many other possible causes being listed. Please don't worry about the white residue, this is a light corrosion that copper releases when it comes in contact with any moisture; this is completely harmless and was most likely from the factory leak and pressure testing. Please feel free to email or call me with any other questions or concerns. Thank you!

Kyler @ Ames
1(800)421-2637
[email protected]

Kyler, thanks for your response. Regarding the radiator cap orientation, I have never seen one at this angle. I talked with Lee Barnes about this, and he agreed that this is incorrect. When I get some time, I will install my original radiator.

Rowland

Needs a good tune , timing & fuel will correct most hot runs.

High Efficiency radiator
 

Kyler, in 58 years of owning this GTO and looking at many GTOs and Tempests, I can't ever remember seeing a radiator cap at this angle. It is so obviously wrong that I am putting it back in the box and will not use it. It would be the laughingstock of car shows. I suggest you people selling these radiators get with the manufacturer and have them made correctly, or at least add a note to your catalog and inform your salespeople to inform prospective buyers of this problem.

I bought my radiator years ago from Performance Years Pontiac. Mine also has the same cap orientation. I learned to live with it and am tired of explaining to people the problem.

That's good to know !

I will stay with the original radiator and forget the $700 cost; I don't want to explain why the cap orientation is incorrect. I have been docked points at car shows for lesser things than this. You would think that restoration parts sellers would get with manufacturers and demand products be made correctly.

I'm guessing any radiator shop could desolder and rotate the fitting .. right?

uttergto, if you would like to return the radiator for credit please email or give me a call. Returning the radiator for a refund is always an option.

Thank you,
Kyler @ Ames

[email protected]
(800)421-2637

I can't do that because the overflow outlet tube is oriented to the radiator cap cutouts. If you rotate the cap, then the overflow is pointing in the wrong direction.

Kyler, I haven't had a chance to remove your radiator; too much work. I will try to get to it this next week.

Before proceeding any further, please feel free to email or give me a call.

Thanks,
Kyler @ Ames