Keeping my baby cool
02-11-2005, 03:53 AM
#1
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Keeping my baby cool I don't know how wide-spread this issue is, but I have probably dropped close to 3K in cooling attempts, and its getting fairly frustrating. Here is my setup- I hope someone has had similar experiences so I can figure this problem out once and for all.
1974 Porsche 911 w/ LS1.
2-core, 19x31 inch aluminum radiator mounted on a rear-leaning 45 degree angle to the car's level.
I have a 20x9 inch rectangular hole cut in my front bumper that allows outside air into a shrouded radiator intake. I have a mammoth 75A electric puller-fan on the inside of the radiator that blows out through a hole in the bottom of the front compartment (pretty decent size hole, larger than the intake).
High-flow aux. water pump in add. to the stock water pump.
Thermostat: 160 degree
The problem is this: After running on the freeway for about a half-hour at 2500-2800 RPM, my temp starts climbin up over 180 and close to the 190 range. From everything I have understood, this is now beyond the ability for the themorstat to control the engines operating tempurature, and I will eventually start climbing into the low 200s.
How do I get the temperature down to 170s or low 180s? Is that this thermostat's operating range? I'm open to any suggestions.
Thanks in advance.
1974 Porsche 911 w/ LS1.
2-core, 19x31 inch aluminum radiator mounted on a rear-leaning 45 degree angle to the car's level.
I have a 20x9 inch rectangular hole cut in my front bumper that allows outside air into a shrouded radiator intake. I have a mammoth 75A electric puller-fan on the inside of the radiator that blows out through a hole in the bottom of the front compartment (pretty decent size hole, larger than the intake).
High-flow aux. water pump in add. to the stock water pump.
Thermostat: 160 degree
The problem is this: After running on the freeway for about a half-hour at 2500-2800 RPM, my temp starts climbin up over 180 and close to the 190 range. From everything I have understood, this is now beyond the ability for the themorstat to control the engines operating tempurature, and I will eventually start climbing into the low 200s.
How do I get the temperature down to 170s or low 180s? Is that this thermostat's operating range? I'm open to any suggestions.
Thanks in advance.
02-11-2005, 04:39 AM
#2
Wow, that's a lot more hardware than I'm running and I've had no problems with cooling. This includes 5 road course events, most of which were in 85+ degF ambient temps. Just a Modine stock-replacement 17.25" x 26.25" single-row aluminum rad w/ plastic tanks cooling it.
Sounds like you've either got an airflow problem, or a coolant flow problem.
1.) Coolant flow: where is your cyl head bleed plumbed? What is the plumbing distance from the water pump to the rad?
2.) Airflow: I'm lost, that fan should move enough air to swap heat off the rad.
Sounds like you've either got an airflow problem, or a coolant flow problem.
1.) Coolant flow: where is your cyl head bleed plumbed? What is the plumbing distance from the water pump to the rad?
2.) Airflow: I'm lost, that fan should move enough air to swap heat off the rad.
02-11-2005, 07:38 AM
#3
Originally Posted by Classic Style
The problem is this: After running on the freeway for about a half-hour at 2500-2800 RPM, my temp starts climbin up over 180 and close to the 190 range. From everything I have understood, this is now beyond the ability for the themorstat to control the engines operating tempurature, and I will eventually start climbing into the low 200s.
ah, so is it only climbing at speed?
all "bottom feeder" cars that get their radiator cooling air from under the car have a air dam.
basicly, its a piece of plastic that drops down below the radiator... so at speed, its easier for the air to go up and thru the radiator then around it.
without it, cars like 3rd and 4th gen Fbodys would overheat when driving down the road.
as for the actual temps you see, they're normal.
the stock operating temps for the LS1 is over 200*.. the fans dont kick on until 226 and 234... unless you change them.
the thermostat only controls the min temp of the system. once that temp is reached, its fully open and its like the thermostat isnt even there..
02-11-2005, 10:00 AM
#4
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Originally Posted by crainholio
1.) Coolant flow: where is your cyl head bleed plumbed? What is the plumbing distance from the water pump to the rad?
2.) Airflow: I'm lost, that fan should move enough air to swap heat off the rad.
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02-11-2005, 10:07 AM
#5
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Originally Posted by MrDude_1
ah, so is it only climbing at speed?
as for the actual temps you see, they're normal.
the stock operating temps for the LS1 is over 200*.. the fans dont kick on until 226 and 234... unless you change them.
the thermostat only controls the min temp of the system. once that temp is reached, its fully open and its like the thermostat isnt even there..
as for the actual temps you see, they're normal.
the stock operating temps for the LS1 is over 200*.. the fans dont kick on until 226 and 234... unless you change them.
the thermostat only controls the min temp of the system. once that temp is reached, its fully open and its like the thermostat isnt even there..
That is what my front bumper looks like. The provision that is shown for a license plate has been cut out to allow air through. I do not have air pulling from the 2 bottom slits but I guess I could if you think it would really improve things.
Also, I did change the stock thermostat to a lower-temp one. The one I pulled out had "212" on the valve.
02-11-2005, 10:31 AM
#6
Originally Posted by Classic Style
Photo of the air-dam
That is what my front bumper looks like. The provision that is shown for a license plate has been cut out to allow air through. I do not have air pulling from the 2 bottom slits but I guess I could if you think it would really improve things.
Also, I did change the stock thermostat to a lower-temp one. The one I pulled out had "212" on the valve.
That is what my front bumper looks like. The provision that is shown for a license plate has been cut out to allow air through. I do not have air pulling from the 2 bottom slits but I guess I could if you think it would really improve things.
Also, I did change the stock thermostat to a lower-temp one. The one I pulled out had "212" on the valve.
changine the thermostat changes the min temp... it still will not change the operating temp, since the engine doesnt sit on the thermostat...
as far as the airdam, looking at it, i dont see one..
im not refering to the bumper, but rather a piece under the car... in this case, you actually WANT some air to get under the car... then it hits the cooling airdam, forcing the air to go up and thru the radiator...
you can see it in the pics below... notice its right infront of where the bottom edge of the radiator is.... making the air go up and into it.
02-11-2005, 03:00 PM
#7
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Your temp climbing as described is exactly what signals us in the Dealership to look under an F-body for that concern. It's quite common for people to break off that lower air dam and then start to have elevated coolant temps at freeway speed.
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02-11-2005, 07:11 PM
#8
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Originally Posted by Oscar Will
Your temp climbing as described is exactly what signals us in the Dealership to look under an F-body for that concern. It's quite common for people to break off that lower air dam and then start to have elevated coolant temps at freeway speed.