HudginJ3 wrote:

"But 50 years ago , these cars ran on the hot California and Arizona desserts with stock radiators and fans and AC systems. I have a hard time believing that I cannot get it to be reliable with stock setup. Hahah"

Having lived in that area, Mustangs were known for over heating. When I converted my 1970, 250 six to a 302 in 1979 I installed a big block radiator for that very reason. Ten years ago I changed the 302 for a 351W bored and stroked to 416 and installed a 4 core aluminum radiator thinking it would help. I'm not sure about that or don't have enough knowledge on this subject. I also installed a hi flow water pump but don't remember anything about it except it is aluminum also. The electric fans made a big difference but I don't know if it is fixed yet. Your questions are very good, I'm learning a lot. I did notice on my current engine that one of the head gaskets looks like it is leaking in the rear of the engine. I have to study that now before the bash.

Ialso read in a 66 owners manual (I think) that the max time to run ac was 30 min,, ha that gets you out of you driveway here in Tx rush hour 

That little electric fan with a shroud smaller than the radiator core is likely blocking airflow at high speed.
When I saw the upper hose sucking flat when revved, that is indicative of either a restricted thermostat or an engine block that is restricting water flow. We know the head gaskets and intake gaskets are on correctly.

Since the upper hose was collapsing, that indicates the water pump is capable and that the radiator is not restricting water flow.

I have same several Edelbrock pumps through the years. Every single one leaked after a couple of years. So far, Flowkooler has worked flawlessly.  I decided to change to them because they were less than half the cost of the Edelbrock pumps. Flowkooler pumps are simply an imported replacement pump with an impeller plate pop riveted in place.  You can buy or make the impeller plate separately.

Here is another thing about that the fan with shroud . So Steve you said that the shroud is obstructing airflow .

The shroud does have these flaps on all 4 corners . I could simply remove them... they are friction mounted ... you don't think those are opening when air is blowing through ? If so I can remove it and it'll add more airflow From the front at high speed .
May change what it does at idle though but... what do you think?

My concern about opening those flaps is that when the fan runs, (especially when standing still) air would take the path of least resistance and go IN through the flap hole, and out through the fan shroud opening, completely bypassing the radiator.

Remember that black 65 convertible with the 347 in it. He brought it in with overheating issues. It had exactly that same electric fan you bought.  Plus a wad of wires.
I removed it and installed a flex fan and 20" radiator with shroud and new thermostat. All heating issues went away.

200 on the highway and 190 in the city, seems like its working the way it should. If you can tell 10 degrees different and accurately I would rather have it that way than vice versa. Depending on your rpm's your engine is running on the highway. Think about it this way, modern cars are running 200-220 at all times with no fluctuations, so for an antique to maintain a 190-200 temp and not vary drastically I would say it's working ok. However I would investigate the upper radiator hose collapsing, it might be because everything is working really good with the thermostat closed, or it might be time to replace the hose.

If you live in the country you could pull out the electric fan and take it for a drive.  See what the temp is at hwy speed.  Pull is back in the driveway before it idles to long and shut it down.  

What number/temp thermostat are you running? Try a lower number?!! Have the fan come on sooner using a different sensor?! Check temp with a different thermometer. Your guage may be off?!
I agree with the other poster....190*-200* ain't really that hot. (I'm sorta old skool and like a "cooler" running engine 160*-180*).
Don't forget...at highway speeds the fan ain't running anyway!
As I have stated before...the Shelby valance solved all heating problems in my 66. I know that would involve body work and re-painting butt....opening up the front of the car made a HUGE difference in mine. Granted, I don't have AC butt eye do have the standard size radiator but it is the old 4-core desert cooler style. Thick butt little.
6sal6............Gonna miss you at the Bash

What SPAL fan you running TKO?

Texas! wrote:

210*F is NOT overheated. The hotter you can run an engine, the better it is. A 190* thermostat begins to open at 190* and is not fully open until somewhere around 210*.
I think you're chasing a non-existent problem. 

  When mine got up to 210 it didn't over heat but It was like crap.  It was smoking and pinging and about ready to die.  Happened at the Mcdonalds drive through waiting for food...LOL 
 

Texas! wrote:

210*F is NOT overheated. The hotter you can run an engine, the better it is. A 190* thermostat begins to open at 190* and is not fully open until somewhere around 210*.
I think you're chasing a non-existent problem. 

Consider that water boils at 212 degrees F at atmospheric pressure.  Or cooling systems are pressurized to 13-16 psi typically depending on the cap you run.  They also run typically a 50/50 mix of coolant and water.  Even at 0 psi the 50/50 mix raises the boiling point to 226 degrees F.  Adding system pressure in that 13-16 psi range raises the boiling point to 260-270 degrees. 

Now that's the point at which it will boil over, and you could certainly argue that its over heating below that temperature.  Temperature, like many other factors is a variable that needs to be considered in your tune.  A mixture set for an engine running 190 degrees F is going to be different than one for 220, etc.  I would assume that as temperature increases the mixture would become too lean, because as temperature rises so does efficiency, because atomization of the fuel improves. 

I didn’t see what diameter your fan was, but did see it was a six blade, i run a 18.25 inch seven blade flexolite flex and have also used seven blade rigid ford oem fan, no clutch- direct drive. Took care of my problem long ago, and this is on a 390 gt, bored .30 over, edelbrock heads and intake. radiator is a four core 24 inch. The fan and the shroud combo is a must, blades half in and half out of shroud.

Here is what I did since the last update : Derale Junk fan is OUT! and so is my Aluminum Radiator with the cooling core area being 15 1/2 inch instead of 16 1/2 like it should be. NOT because it makes a huge difference with an inch of vertical core missing, BUT, the 16" fans were just not fitting in it like they were supposed to.

So I now have a 3 row copper radiator : cleaned, pressure checked, and such. Stock style .
SPAL 3000CFM fan hard mounted on the radiator support (not zip tied on the radiator fins like people do.) this is an actual mount using the SPAL strap mount, and 65 era shroud mounts.

Air is out of the system completely. Fan controller is almost set just right.. need to tweak a bit ..
Went for a long highway run yesterday running AC the whole time, and cruising at 80mph , and the car never went above 190 . And at exiting, and stopping and idling at the red light, where usually the car would have overheated in 78deg F  weather wth the AC on. THe car sat perfectly at 190 the whole time. Got stuck in a jam, and again the car never overheated.
So this is looking like an end of an era of overheating issues for me!!!!! YAAY

But ofcourse as you can assume: with fan drawing 20A and AC, and MSD system etc, the stock alternator is not able to keep up with all this at idle. I tested the voltage to the battery, at 750-800 idle, FAN A/C and radio on, the battery got 12V from the alternator. So , a new 3G 1 wire alternator setup is on the way from PA-performace, with the conversion setup that lets the dummy light still function .

This setup comes in tomorrow, and will complete my upgraded charging system and the cooling system.

Also found issues with my spark plug wires (had two bad ones, replaced them, tested others)
I did retard my timing a bit too much ,and I feel it as the engine is sluggish. retarted timing generates heat too, and I want to get the timing set again using my vaccum guage..

Then i can move on to installing seat belts in the rear seat :D :D