1966 mstang overheating

[Ron Richardson]

Ihave a 66 mustang with a 289,atuo,a.c.. It has a new rad. ,an elect. cooling fan mobil oil any other suggestions that might help ?

[River Bum]

I run a 180* stat and love it. 98% of the time it now runs at 180* and the other 2% it has hit 210* at 100* outside though with a/c on. Changed the coolant?

Ron

[Mike Hill]

you say the rad. is new but how many cores does it have? if its only a two you may need a three core if the 180 stat. doent help. since you do have ac is the cooling fan strong enough to pull enough air through the condenser?

[Ron Richardson]

It has a 3 core rad. already and a high volume water pump to, I'm wondering if the flow could be to fast if that's possible ?

[wileys_farm]

Your radiator won't flow with the thermostat closed. Don't beleive me? Take your cap off and look while your engine is cold and running. Ya there's water in there but it's not flowing. If it is you have thermostat trouble. Check this first. If water is flowing all the time its your thermostat if not your thermostat get back with us.


Are you perhaps getting water in your oil? Oil in your water?

If everything is good I would bet you have gotton your timing out of wack. If your engine is not in time they WILL run hot. They will start out fine but when the engine first heats up the temperature will increase dramatically, and keep goin until you shut it off. Did you use a quality timing light when you put your engine in time? Get back with me.

Wiley

[River Bum]

FOOTNOTE: water wont start to move until car is warm or hot. So if you try what wiley said, wait until warm or hot and remove pressure before opening cap!

Ron

[River Bum]

I have a question. I had timming done about 6 months ago on Suburban. Then just had it done again (long story, the pep-boys thing) and they said it was off 3* last guy had a bad gun or? This guy just typed in 4* shot the light and said look its off, turn the dist. and all done, it was on the mark. He also showed me the RPM's before he fixed the timming with his gun too, it was 770. Not sure what normal is, nor do I know if the RPM goes up with the timming as he turned it up (advanced it)

Ron

[wileys_farm]

The last person may or may not have known that the timing is off. Many people set the timing on a vehicle in different degree's to their satisfaction. See on a small block 350 some people like it about 8* some people 10* and even some go to 12*. See there is a 4* margin here. Because one man likes it and thinks it would run better at 8* don't mean its wrong its just a personal preference. Usually a chevy engine has a 4* increment. Look on your aftermarket timing chain sets and you will notice the extra keyways +4* 0* or -4*. I always try to center the cam and crank up on zero and then work with the distributor for a couple of degrees. I have seen very few bad timing guns but it doesn't mean there not out there. I know your engine is a 454 and this timing thing I'm saying is for a 350 has little in common but the fact of the matter is if I set your timing at 10* and then you go to a friend's house and they put a timing light on it and they say they always run at 14 or so, then everyone would think the way I set it was wrong. When I wasn't. People adjust the timing for more top end, mid range, or low end. It just depends on the preference. I hope this made since to you. If not write back and I will explain it another way.

[raceman6135]

Ron:

Are you running any anti-freeze/coolant in the system, or are you running straight water? If you have coolant in the system, make sure it's no more than a 50/50 mix, unless you live in a really cold climate (like I do). If you have too much coolant to water, that will also decrease the cooling ability.

Timing, like wileys said, is mostly a matter of preference, as well as what modifications have been done to the engine, how heavy the vehicle is, and even what altitude you live at. The higher you live, the more advance you will need because the air is thinner/less dense and will lean out your mixture, making it more difficult to ignite. This is the reason old Dodges came with electronic ignition on their "lean burn" engines in the early '70s.

Speaking of mixture, could you be running lean? Pull a couple of spark plugs and check their colour. They should be a light tan to light chocolate colour. If they are lighter than that, the engine is running too lean (not getting enough gas), and then you must check your fuel system to see what adjustments must be made. Sometimes it's as simple as enrichening the idle mixture screws on the sides or front of the carburetor (depending on which carb you are running).

To answer River's questions, yes, changing the ignition advance at the distributor will affect idle speed. That is why tuning a vehicle is a multi-step process. Once the timing is set, you may find that you have to lower the idle speed and sometimes even adjust the idle mixture screws on the carburetor.

As for idle speed, 770 rpm is just fine, as long as it idles nice and smooth. For a stock engine, 770 rpm is pretty darn perfect, but I've modified engines with increased compression, hotter camshaft, a better intake manifold, carburetor and headers and have had to increase idle speed to 1000 rpm. It does "clunk" the U-joints a bit when put into gear, but this engine is made for performance and may not be the same as your situation at all.

DJS