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Discussion Starter · #1 ·
What would be the best way to flush the block before installing a new 3 core radiator? I have a Zerex flush kit to clean the whole cooling system, but I want to make sure the block is clean before installing the new radiator. Isn't there a plug on the engine block that can be removed? I had planned on changing thermostats as well and going to a 160 degree to keep the engine a little cooler. Is this a good idea? Thanks, Jarrell
 

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I agree w/ you on the lower thermo for the summer. As long as you don't have a FI system. A high pressure flush after the Zerex, going from the top down is the best route to get out the heavy particles.
My 2c's
 

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Jarrell, When I got my V-6, I bought a submersible aquarium pump, 500 GPH, and ran a pint of flush through the engine from a 5 gallon bucket filled with water. I ran the system for 12 hours, then drained and ran clear water through the engine until all I had coming out the hoses was clear sparkling water. My take on changing to a cooler thermostat for summer is don't. Contrary to popular belief a cooler thermostat does not necessarily keep the engine cooler. It may not allow the coolant to stay in the radiator long enough to get sufficiently cool and may actually allow the coolant to free flow through the radiator as if the thermostat was not there. I have seen folks overheat their engines in the high deserts of CA and NM by taking out their thermostats. JMTCW.

Ron
 

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Cleanliness is.....

One way to help clean the block while the engine is assembled (and even still in the car!) is to remove the water pump so that access can be gained to one side of the block's waterjacket.
A high pressure garden hose and a length of 1/8" welding wire can loosen up lots of rusty crud that has settled to the bottom of the jacket.

The best way is to acid dip the completely disassembled block during an engine rebuilt - but that requires the engine to be taken out and apart, ofcourse.

Overheating is due to lack of cooling capacityand a 160 degree thermostat does not help that much. It may delay the inevitable just a wee bit by stating the water circulation at a lower temperature. However, on cooler days (or if the cooling capacity of the system is sufficient) the engine will not reach opperating temperature and sludging of the oil can take place due to water not being forced out by the heat. That is why the oil level often drops when a hot run is done after cold, short runs around town - the water which has condensed into the oil from blow-by etc. has been boiled out of the oil.

If overheating starts to occur then turning the interior heater on fullbore can increase the cooling capacity enough to get home.
Bakes the driver but saves the cylinderhead.:D
 

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Discussion Starter · #5 ·
According to the FSM, (I didn't have it last night) there's a drain plug on right side of cylinder block. Couldn't you put in a nipple and attach it to a hose, let the water run slowly back through the block and back flush the block in the manner that Ron suggested? Or just run it at as much pressure as it could take without blowing the hose off, to remove any sediment before it settled? In the same vain, I thought about checking the water pump, and or, replacing it while there. My idea being I'm there, spent a good deal of money on the radiator, water pump would be cheap insurance, do it right the first time and not have to go back to that area for a while. Of course new upper/ lower radiator hoses, etc. Jarrell
 

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It's been my experience that the factory coolant drain plugs are usually so rusted in place they can only be removed by the heat/wax method. Not something you want to do in the car generally.
 
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