Just got my 54 with a 239v8 up and running but after letting it run for awhile temp kept rising. I just put a brand new radiator (stock) new thermostat (180) and new hoses. I let it run until it got to around 200 degrees and shut it down. I felt of the upper radiator hose and it was cold. I know I put the thermostat in the correct way I double checked it before I put the top hose on. The only thing that I didn't put on new was the water pump but it was fairly new. Any ideas would be appreciate.

 

If you pull a heater hose there should be good flow, that would show the water pump impeller is doing its thing? If it has sat for a long time a good flush of the block?

 

Sounds like your new thermostat may be defective and not opening as it should.

 

Run it without the thermostat and look to see if fluid is flowing into the radiator....

 

So if I start it up and pull one of the heater hoses off I should immediately get water flow if water pump is good?

 

If you pull the heater hose from the pump. If you pull the return hose and the heater core is plugged or the heat control valve is stuck shut you might get little or no flow. Just remove the radiator cap (while cold) and watch for water movement in the radiator tank. If the pump is pumping and the thermostat is opening (or removed) the flow should be easily seen once the engine is warmed up. Check the coolant temperature with a thermometer stuck in the tank water (an inexpensive meat thermometer will work as long it reads in the 100 - 250 range) rather than relying on the instrument gauge or a IR temp gun.
If you want to check the thermostat, when out, put in a pan of water on the stove and bring the water to a simmer. The thermostat should have popped open if working.

 

Seems crazy to me that they haven't found a better way to do what a thermostat needs to do. Below is 2 stats, the one on the left caused a boil over but the new one on the right is nothing short of a major restriction in the system even at wide open. Can it be true that even high end luxury cars with sixty zillion microprocessors still have one of these "stone hammers" in their power plant?

 

the "major restriction" is often necessary to keep the water from circulating too fast when the engine is operating at higher speeds, If not restricted, the water moves thru the radiator and back to the engine so quickly it doesn't have enough time to give off it's excess heat in the radiator, resulting in a boilover. The further we drive at higher speeds the worse the problem. The failure rate on thermostats is really very low, they are both dependable and cheap to produce, a rare combination these days. A different solution i.e. a computer controlled variable speed electric water pump, would be much more complex, expensive and consequently would have more components exponentially more likely to fail. A perfect example of the K.I.S.S. principle.

 

Just a thought, did you get all the air out of the system? I always drill a 1/8" hole in the thermostat flat metal plate to allow the air out.

 

X2 on this

 

it sounds like to me that you still have air in the system.

 

Ditto, air pockets cause exactly what you described.

 

Park it with the nose up hill. Warm it up with the cap off
than let it cool down. Top it off and do it again. This should
work the air out if the cap is the high point in the cooling
system. This is why to put it on ramps on a steep drive.
Work the air out. Make sure the top rad hoses are not above
the fill cap ever. Not even the heater core should be above the
cap. But some are and this is how ya purge out the air. One way
anyway. Works for me.

I hope after all this work ya don't find a bad block.

 

Thanks guys will try these methods tomorrow.

 

I drill a 1/8" hole in my t stats to allow air out on the refill