Cooling Tip for you
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
What is important in cooling of IC engines is the RATE of heat flow, BTU/hr. The engine makes heat (BTU/hr) and the radiator gets rid of heat (BTU/hr). When the radiator gets rid of heat as fast as the engine makes heat, the coolant temperature will be stable. If the radiator gets rid of heat not as fast as it is being made, the temperature rises. The rate (BTU/hr) the radiator can get rid of heat is determined by a number of factors, but the largest is the difference between the inlet coolant temp and the air temp passing through the radiator. Air flow rate (cubic ft. per minute) is also important, slow airflow, slow heat transfer rate. Mechanical fans on older cars and electric fans on and after 84 vettes ensure airflow when the car isn't moving or moving too slow.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
Thread Starter
Pro
Joined: Jan 2009
Posts: 686
Likes: 4
From: Austin Texas
I originally micrometered the inside of the gooseneck and, by removing casting flashing, have increased the cross sectional area in the straight pipe of the gooseneck where it meets the dome by 13.6%
Yes, this will increase potential flow of coolant through that gooseneck, and the amount of coolant entering the engine, provided that - the formerly puny 0.940" dia opening where the pipe met the dome was the most constrictive part of the system, which it appears to me to have been. Opening it up seemed like a good idea, unless the casting flashing was purposely engineered in. My guess is that it wasn't.
Now that two days have passed I can report my engine runs steady at 192-3 F using a 180 stat. I can also report that when I let it curb idle to the point that the fans kick on, the rate at which the temperature drops is greater than it was prior to my opening and radiusing the juncture of the straight pipe poriton of the gooseneck at the dome, and I conclude the 13.6% increase in cross sectional area on that part has had an impact on cooling in my engine.
Casting flashings are a manufacturing variance. All I'm suggesting is that some folk might want to inspect theirs to identify a potential opportunity to putting that ID to its design config. size by removing that variance. If next time you pull your gooseneck and you're happy with what you see, then do nothing and remain happy. If you have a restrictive bead of flashing in there there as I did, you might consider removing it.
It used to take my engine about 5 mins driving at hiway speed to get it to cool down from the in-traffic temperature. Now, I watch that temp gauge drop like a rock, in about a minute. You heard it here first.
Yes, this will increase potential flow of coolant through that gooseneck, and the amount of coolant entering the engine, provided that - the formerly puny 0.940" dia opening where the pipe met the dome was the most constrictive part of the system, which it appears to me to have been. Opening it up seemed like a good idea, unless the casting flashing was purposely engineered in. My guess is that it wasn't.
Now that two days have passed I can report my engine runs steady at 192-3 F using a 180 stat. I can also report that when I let it curb idle to the point that the fans kick on, the rate at which the temperature drops is greater than it was prior to my opening and radiusing the juncture of the straight pipe poriton of the gooseneck at the dome, and I conclude the 13.6% increase in cross sectional area on that part has had an impact on cooling in my engine.
Casting flashings are a manufacturing variance. All I'm suggesting is that some folk might want to inspect theirs to identify a potential opportunity to putting that ID to its design config. size by removing that variance. If next time you pull your gooseneck and you're happy with what you see, then do nothing and remain happy. If you have a restrictive bead of flashing in there there as I did, you might consider removing it.
It used to take my engine about 5 mins driving at hiway speed to get it to cool down from the in-traffic temperature. Now, I watch that temp gauge drop like a rock, in about a minute. You heard it here first.
Last edited by ChrisWhewell; Apr 28, 2009 at 05:41 PM.
Pro
Joined: Mar 2008
Posts: 702
Likes: 0
What is important in cooling of IC engines is the RATE of heat flow, BTU/hr. The engine makes heat (BTU/hr) and the radiator gets rid of heat (BTU/hr). When the radiator gets rid of heat as fast as the engine makes heat, the coolant temperature will be stable. If the radiator gets rid of heat not as fast as it is being made, the temperature rises. The rate (BTU/hr) the radiator can get rid of heat is determined by a number of factors, but the largest is the difference between the inlet coolant temp and the air temp passing through the radiator. Air flow rate (cubic ft. per minute) is also important, slow airflow, slow heat transfer rate. Mechanical fans on older cars and electric fans on and after 84 vettes ensure airflow when the car isn't moving or moving too slow.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
The old wives tale that I heard was realated to the small diameter holes in the rear water jacket gaskets of the lower intake manifold.
Can anyone explain why these they aren't opened up like the front water jacket gaskets are?
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
What is important in cooling of IC engines is the RATE of heat flow, BTU/hr. The engine makes heat (BTU/hr) and the radiator gets rid of heat (BTU/hr). When the radiator gets rid of heat as fast as the engine makes heat, the coolant temperature will be stable. If the radiator gets rid of heat not as fast as it is being made, the temperature rises. The rate (BTU/hr) the radiator can get rid of heat is determined by a number of factors, but the largest is the difference between the inlet coolant temp and the air temp passing through the radiator. Air flow rate (cubic ft. per minute) is also important, slow airflow, slow heat transfer rate. Mechanical fans on older cars and electric fans on and after 84 vettes ensure airflow when the car isn't moving or moving too slow.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
With constant reasonable airflow, slower coolant flow in the radiator results in low heat flow out of the radiator (low BTU/hr) for the reason that the average coolant temp in the radiator has decreased (inlet temp minus outlet temp) and the heat flow rate is determined by the difference temp between the coolant temp and the air temp.
The thermostat controls coolant flow rate (gallons/hr) and when the radiator isn't removing heat fast enough, the coolant temp rises and opens the thermostat more which increases flow rate, and allows the radiator to remove heat at a higher rate to match the rate heat is being made in the engine. The radiator can remove heat faster with faster coolant flow because the average radiator temperature increases (inlet temp minus outlet temp) and thus the temp difference between the air and the coolant rises producing higher (BTU/hr). The engine temperature will stabilize when the heat flow out of the radiator matches the engine heat flow into the coolant.
