'67 Fastback Overheating

[Thasador]

I have a 1967 Ford mustang fastback. Right now it has a 351 Cle engine, 4 barrel holley carb, aluminum intakes, flowmaster dual exhaust system, new radiator.

Now whenever the mustang is not in motion, it has a tendancy to overheat. I put in a new radiator with new hoses in the other day and made sure my water pump and fans still operator. But it still overheats. Am I dumping too much fuel into the combustion chamber or does the aluminum intakes have a part in this? Please help me out here.

[mechhound]

Originally Posted by Thasador

I have a 1967 Ford mustang fastback. Right now it has a 351 Cle engine, 4 barrel holley carb, aluminum intakes, flowmaster dual exhaust system, new radiator.

Now whenever the mustang is not in motion, it has a tendancy to overheat. I put in a new radiator with new hoses in the other day and made sure my water pump and fans still operator. But it still overheats. Am I dumping too much fuel into the combustion chamber or does the aluminum intakes have a part in this? Please help me out here.

You say "Now whenever the mustang is not in motion, it has a tendency to overhaeat." If I understand it right as long as you are driving the car it stays cool, correct? If the answer to that is yes, that tells me that your fan is not pulling enough air through the radiator. When you are driving, the speed you are driving pushes that much air through the radiator. No shroud?, fan mounted backwards?. Just some thoughts. As long as it is runnng good, I'm sure your intake or fuel system has nothing to do with the overheating.

[351wStang]

Make sure you have enough water in the system, no air pockets.
Make sure your water pump is turning the right way.
Make sure your thermostat isn't stuck open.
Make sure your fan is turning the right way.
- Also what fan do you have on the car? Flex-fans are prone to overheating.

I have the stock 2 core brass radiator and mechanical (non-clutch) fan without a shroud in my '69 Cougar. It's got a 475hp 351w and runs just over 155* with a 160* t-stat in it. I'm actually installing a 180* t-stat to try to get it to heat up a little.

You may want to check your timing. If its not advanced enough then its will cause your motor to overheat.

[Thasador]

I have a dual fan system that sits behind the radiator and a single in front of it. I dont know exactly what type of fans they are because they are about 10 years old. I know they are made of polyurithane or some other material. They are installed correctly and that is one of the things I looked at. The water pump was placed in correctly with the help of my father (original owner and grease monkey) And I just purchased a new thermostat but have yet to put it in. I was thinking that the upgrade from a 289 stock engine to the 351 with the 4 barrel holley carb would be producing too much power and heat. Maybe that the radiator is not up to par with the amount of power i am using? I have a replacement radiator but it was the size for a 289. Can that be the problem?

[mechhound]

Originally Posted by Thasador

I have a dual fan system that sits behind the radiator and a single in front of it. I dont know exactly what type of fans they are because they are about 10 years old. I know they are made of polyurithane or some other material. They are installed correctly and that is one of the things I looked at. The water pump was placed in correctly with the help of my father (original owner and grease monkey) And I just purchased a new thermostat but have yet to put it in. I was thinking that the upgrade from a 289 stock engine to the 351 with the 4 barrel holley carb would be producing too much power and heat. Maybe that the radiator is not up to par with the amount of power i am using? I have a replacement radiator but it was the size for a 289. Can that be the problem?

To put things into perspective, you would create a lot more heat driving down the highway at 60 or 70 MPH than you would sitting idleing. If it would run cooler driving down the highway at speed than when idleing, I would say your fans are not moving enough air through the radiator. How warm does it get sitting and idleing? What is the temperature outside at this time? I assume all the fans you have are electric, do they run all the time or just kick on at a certain temperature?

[Thasador]

I have a toggle switch to turn on all fan circuits. I have not drive my mustang since california. Currently i am residence to Washington state, much colder environment. But i do not wish to drive if it is going to harm the engine. But will a small radiator that is not up to par with a bigger installed engine do it?

[351wStang]

It could. Most of the 289/302 radiators were single core. 351w/c radiators were 2 core & most FE stuff was 3 core.

Sounds to me like a fan/rad upgrade is needed. Spend the money once and get a 16" Spal fan, you wont regret it, its the only one you will ever need.

[Thasador]

Thanks you guys for your help. I'll see what I can do.

[351wStang]

No problem. Got any pics of the car? I love the old ones.

[Thasador]

I'll get my digital camera tomorrow from my ex-fiancee and grab a few shots for you guys. Rebuilt 351 cleveland with only 1,800 miles on it. new jet black interior, origial/referbished dash and gauges. Hurst shifter 4 speed manual. The only thing left to do after this overheating problem is the paint job. Fiberglass "dragon snout" hood with functional scoop. ^_^