KMatch

I should be above this with a hundred years experience and all, but I'm getting my *&# kicked...

Fresh rebuild on 302 stock bore. AFR heads, no difference from the GT40s with temp. 36° timing on Trickflow stage 1 cam. VintageAir a/c, not much difference with it on or off. New 3 row copper/brass rad with either 185 or 195 t stat - it's been a few months and I don't remember getting dressed this morning. All shoved into a 65.

Highway speeds are always 195 unless allowed to creep higher in town - then it takes a bit to regain control. With a Hayden electric fan, the temp at intown speeds would creep to 230ish. I kicked the ideal around about a clutch fan from a crown vic (the donor car) with no shroud and saw a "slight" improvement so I installed a shroud and trimmed the 18" fan to fit in a 17" hole. Still higher than my comfort zone nearing 230 at times in town. I hate snake oil, but after all conventional thinking petered out, I drained the rad to thin the coolant and put in water wetter topped off with water to get close to the 15% coolant mix called for. Now it creeps ABOVE 230 which it never did before. Did I mention how I HATE snake oil?? (Those of you claiming 30° drops... how damned hot were you running it before??) Looking at the front end of this thing, it appears having an engine requiring a cooling system was an afterthought. There's simply no room for adequate airflow. What are some ideas to get air into this thing without looking like a hack job??

dodgestang

Well it has been slightly warmer ambient as well.

You can bolt the 67 sized radiator into the stock spot. It is larger than the opening but the actually cooling fins of the radiator are the same size as the opening in the 65. You can also trim out the radiator support and stuff a huge radiator in there if you want....but that involves cutting sheet metal.

scottybaccus

It sounds like highway speeds are OK, but around town is getting you hot under the collar. If that's the case, you don't have an issue with air intake. you have an issue with making air flow at low speeds. This is the weak point of a clutch fan. It works best at road speed where you may not need it.
You probably will need to go to electric fans. (yes, two of them)

The reason it's hotter after a fresh rebuild is likely a combination of summer temps and the tighter tolerances in the engine generating more friction heat. You might try experimenting with different engine oils, but that brings you back to the serpent medicine.

Best bet for low speed cooling is one fan on a t-stat operated relay, a nother on an A/C relay. You might find you just need them both on the T-stat. I posted some particulars to think about here: https://mustangforums.com/forum/clas...ng-w-pics.html

maybe something there worth reading.

68GT 302

Could it be a water pump issue? I replaced mine and noticed about a 10deg drop in temps.

gjz30075

Are you sure you fully 'burped' the system? You could have added air pockets with the change.

wgc68nyc

Mine has been having similar problems ever since I had the A/C added.

Is your condenser right in front of your radiator? The fact that the condenser gets the initial airflow and then the rad is my theory on why I am running hot.

I intend on running a hipo Spal puller on the inside and the biggest pusher I can fit on the outside on the condenser and see if that helps.

Let me know if you find a solution though I am starting to feel like there may not be one.

Does anyone have an mustang with an aftermarket a/c and have been successful at keeping their engine cool at 90+ temps while using the a/c?

If so what is your setup?

KMatch

Burped, vented cap with reservoir, 1200 miles of tinkering with various systems including coolant issues with no real changes. The same exact clutch cooling fan that was cooling a family truckster with the same shortblock and transmission and it can't hack it all of a sudden. The only real difference besides a "slight" performance increase would be about a half gallon reduction in coolant capacity and a ton less airflow due to the restrictive grille/valance combo. It's dying for air and with the a/c condensor, trans cooler, and hood latch there's just not alot of room for a pusher fan which is what I'd like to do.

KMatch

Brand new specd for a 65. Verified before install.

KMatch

I want to reverse my electric and use it as a pusher, but where do you find the room? And it was assembled on the loose side - new rebuild kit in honed bores equals looser than factory. I've gone from Pennzoil 10-30 which turned to gunk, to Mobile1 10-30 which rattled, lowered the oil pressure and smoked, to 15w40 SM rated which I use in my shop for a bus fleet. Pressure is better, all is quieter, temps always the same regardless of oils and all these oil changes with 1200 miles on it...

JMD

How big is your radiator?

Yea I know it does ok at highway speeds but...

A cooling system that is marginally satisfactory with iron heads, might be marginally unsatisfactory with aluminum heads...

On Saturday I installed an aluminum radiator with a 2" core in favor of the 2 row copper rad on my 85 Mustang, it made all the difference,,,,

A 2 row that is half plugged up doesn't make it...