I installed aussie heads on a 400 and when it warms up it throws the water out of the raidiator as if a head gasket was installed backwards. I checked and they are correctly installed. does anyone have any suggestions?

 

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Make sure you have the RIGHT thermostat. It must look like this one:
http://homepage.mac.com/joshkeady/33...hermostat2.jpg
There is a port under the 335 series engines that regulates flow thru the engine and is controlled by that copper colored "skirt" under the thermostat.

Note: The picture above is of a 180°F thermostat but a 190-195°F stat must be used on a 351M/400.

Coolant flow in the 335 series; 351C/M/400:
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The 335 series routes coolant water in a unique fashion; directly from the head to the block without passing thru the intake manifold so the manifold is "dry". Coolant flows from the head to the block, and then into a chamber below the thermostat. When the thermostat is closed water flows downward thru the water bypass orifice (part number D0AZ-8K517-A on a Cleveland) and into the water pump for recirculation. When the engine warms sufficiently the thermostat opens and most of the coolant flows through the thermostat and then to the radiator for cooling with a small portion still flowing thru the bypass orifice. If the wrong thermostat is used the orifice will not be closed off properly, or if the orifice is removed on a 351C, a major portion of the coolant will flow directly back to the water pump rather than through the radiator which will cause overheating and hot spots. The hot spots will throw coolant out.

 

is it possible that the heads have had the "Clevor" modification done to them? this would make them act as if the head gaskets are on backwards

 

Thermostat must be 190-195 ? Why is that? I have a 170 if memory serves correctly on mine, is that a problem?

 

Broncochuck
Ford designed these engines to operate in the 190-195 degree range. It has to to with efficiency with higher temperatures in the combustion chamber. The 170 won't hrut your engine, it just lets it run too cool for best efficiency.

 

Actually 170°F will hurt the engine. There is a chemical reaction that occurs on the combustion chamber walls at lower temps that accelerates wear. The wear rates double for every 10° below 180°F. 180°F is the minimum temp that should be used and the stock temp is much better. Lower temps also increase fuel use and decrease efficiency. Some of the increased longevity of modern engines is due to their higher operating temps.

 

Wow, I never knew that. 192 degree thermostat is already bought and wiuting for the cam install this weekend.

 

Don't feel bad, very few people know that. I was just lucky enuf to have access to SAE articles and papers on a variety of subjects and lots of time to read them as part of my job for years.