raw water cooling system Q....

djmakko

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{lease help me understand the cooling system a little better, I have an 87 260/5.7 alpha 1. my thermostat housing has 6 holes comes with the T with balls, one hose is the intake , one to water pump, two to risers, two to exhaust manifolds,
Now I have seen some engines also 350's with a thermostat housing with 4 holes they are still raw water cooled but the two risers had plugs on them , so then one hose is the intake , the other is the water pump , and the two remained to exhaust manifolds, my question is what is the difference? Reason I asked is because I have to change my thermostat housing due to a different intake manifold that came with my new engine , sits about 4 inches to far and the water intake hose is directly above the Power Steering belt.
 

Don S

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Re: raw water cooling system Q....

{lease help me understand the cooling system a little better, I have an 87 260/5.7 alpha 1. my thermostat housing has 6 holes comes with the T with balls, one hose is the intake , one to water pump, two to risers, two to exhaust manifolds,
Now I have seen some engines also 350's with a thermostat housing with 4 holes they are still raw water cooled but the two risers had plugs on them , so then one hose is the intake , the other is the water pump , and the two remained to exhaust manifolds, my question is what is the difference? Reason I asked is because I have to change my thermostat housing due to a different intake manifold that came with my new engine , sits about 4 inches to far and the water intake hose is directly above the Power Steering belt.

You must have a newer engine, or the cooling system was upgraded because the check balls didn't start till 89.

Here is the system flow diagram. It should explain how it works.

View attachment #15 GM V8 89-92 554.pdf
 

djmakko

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Re: raw water cooling system Q....

Don ,
the original engine is an 87' perhaps the previous owner upgraded it (IDK), but that is what i have, a 6 hole thermostat housing, but now im installing in a new engine 2004' all the accessories fit in to the new engine from the old, except the T stat Housing, I need to replace it but , all i can find are 4 hole housings , the diagram explains how it flows I understand that , what i dont quite get is the 4 hole set up why are the inlets on the risers plugged , and still a raw water cooled . im confused!
 

Bondo

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Re: raw water cooling system Q....


Ayuh,... The water Flows are different, but the water is still exhausted through the risers,...

It comes up from the manifold below, that's all,...
 

djmakko

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Messages
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Re: raw water cooling system Q....

thanks Bond-o , so i can use either set up ? 4 hole and 6 hole , and if i use the 4 hole would i then change the gasket between raiser and manifold or keep the same? or leave it alone ,
 
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