Thermostat Mod – Test Data
Pro
Joined: Apr 2005
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From: TEMECULA CALIFORNIA
St. Jude Donor '06-'07-'08-'09
I HAVE A SERIOUS FEAR OF MOTORCYCLES SO I DONT RIDE. BUT THAT IS THE BIGGEST DEALER IN THE SO CAL AREA.
Instructor
Joined: Nov 2007
Posts: 129
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From: Houston, Texas
Regarding galvanic corrosion, I wouldn't think that there is enough difference between the two aluminum alloys for corrosion to occur. It appears that the thermostat has a stainless steel bracket that comes into direct contact with the aluminum housing. So, if this material combination hasn't caused corrosion, then the two types of aluminum shouldn't be an issue.
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Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Regarding galvanic corrosion, I wouldn't think that there is enough difference between the two aluminum alloys for corrosion to occur. It appears that the thermostat has a stainless steel bracket that comes into direct contact with the aluminum housing. So, if this material combination hasn't caused corrosion, then the two types of aluminum shouldn't be an issue.
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From: Lackey, my own dragstrip VA.
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Enough of the personal insults and attacks for those with posts deleted.......
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Burning Brakes
Joined: Mar 2006
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From: Bedford IN
This seems like a lot of work when you can just buy a therm to do that. I put the 160 in mine and at highway speed runs at 174. In town it runs in the range you are looking for. I also had the fans adjusted when the car was tuned to support it.
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Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Obviously you have a better method/idea on how this should be done, please enlighten us. By the way, I would also like to know how the air gets hotter faster as well.
Last edited by vettenuts; Feb 26, 2008 at 04:12 PM.
Instructor
Joined: Sep 2006
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From: HOUSTON TX
this post seems to have gone down hill for you. i see alot of deleted posts. being an engineer you should see that flow would play a part in this as well as how air would heat faster than water. i am not here to suggest how to test but if you are going to put something out there don't expect people not to be skeptical of your results and methods. you are not the only engineer that is a member of the forum.
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Team Owner
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From: At the beach in little Rhody
You have a submerged air pocket in water with metal that is all basically the same temp. Explain the air heating faster please as it can't heat faster or exceed the surrounding water temperature. Also read above, I explicitly stated that the measured performance wasn't indicative of the final outcome. It was a parametric comparison. Read post #11.
As for the posts going downhill, I guess I missed those.
As for the posts going downhill, I guess I missed those.
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Team Owner
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From: At the beach in little Rhody
Ummmm, no it isn't. If you talk to ET, you will see he is running a cooler thermostat in the summer as well. But he also ensures his oil temp exceeds 200 degrees and that his engine stays above 180 minimum and he tries to keep the coolant temp within a specific range as well based on data he knows provides engine longevity and performance (not too cold). He has what he has referred to as the "sweet spot", the only thing I am trying to do is keep my motor within the same range he defines. With the stock stat and radiator, there is a very small temperature window to work within and a thermostat that opens slightly earlier will make it much easier to keep the motor within this temperature range window.
Last edited by vettenuts; Feb 27, 2008 at 05:37 AM.
Safety Car
Joined: Sep 2003
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From: Cape Coral FL
Bob, thanks for doing the leg work and posting the results. Now that I have my LS2 up and running, I've started playing with it's thermostat also. I put an LS2 water pump in for now and it's using the later model thermostat. I'm also interested to see if the temperature curve is skewed due to the higher kw output of the engine. I'm interested in learning about 'spikes' in temperature due to sudden changes in power output and how a lower temp thermostat will effect to that.
One thing I didn't know is the LS2 thermostat is set to open at 187 degrees, a full 8 degrees cooler than an oem LS1 thermostat. Also I am running an LPE oil cooler. I'm really not interested in installing an oil thermostat unless it is mandatory. Having said all this I am trying to achieve your goals also. My differences mainly are larger displacement using the oem cooling system. That may change in the future.
One thing I didn't know is the LS2 thermostat is set to open at 187 degrees, a full 8 degrees cooler than an oem LS1 thermostat. Also I am running an LPE oil cooler. I'm really not interested in installing an oil thermostat unless it is mandatory. Having said all this I am trying to achieve your goals also. My differences mainly are larger displacement using the oem cooling system. That may change in the future.
Le Mans Master
Joined: Jul 2010
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There have been two threads recently on modifying the stock thermostat (a modification that isn’t discussed much anymore) and I recently got to check the new thermostat I just bought out of the box and then with a few different thickness shims. My goal is not to get a real cold thermostat, but rather get one to open around 180 degrees with good flow by the time the thermostat is in the low to mid-190’s. I am hoping that with the DeWitts radiator I have on order and this slight modification to the thermostat, I will be able to keep the engine temperature in a narrow range from 185 – 195 degrees from spring right through fall while ensuring my oil temps are over 200. That’s the goal; guess we’ll see how things work out in the coming months and if the oil doesn’t heat up enough I will re-install the stock unit. The other thing worth noting, the temperatures I am trying to achieve are based on how I typically drive the car as I don’t race the car so extended high RPM runs are simply not in the cards.
In the first photo the thermostat has been disassembled. You can see one of the shims that I made and the hole into which it is installed. The thickness of the shim will alter the opening point by lowering it, or as is the case if you get to approximately 0.100” thick shim, the thermostat will barely close.
One of the problems I ran into was how to measure data so it wasn’t subjective and I could repeat the test fairly well between the different shims and get a good comparison. After some messing around with the test, I decided to take the temperature at three points in the opening sequence. First, by hanging the thermostat such that the neck was downward, it was easy to trap air behind the rubber door that opens in the thermostat. The first data point would then be when the thermostat opened enough to release the trapped air. This doesn’t take much movement at all and you can barely see the rubber door move at all when this occurs since the movement is so slight. The second point of measurement would be when the rubber lip on the seal was even with the flat mounting surface of the thermostat (see the photo). Finally, I took a third measurement when the rubber lip was 0.2” from the same flat mounting surface. While this seems to be a precise number, it is actually the width of my flat screwdriver that I could hold in the water and use for a measuring tool. With one edge of the screwdriver against the flat mounting surface of the thermostat, when the lip was even with the other edge of the screwdriver blade that is when I wrote down the temperature.
Below is a photo of the shim installed prior to re-assembly of the thermostat.
Next was the method of heating up the thermostat so it was immersed in water. In the next photo you can see I bent up a coat hanger and hung it from a small stick across a large pot of water (my wife thinks I should be committed at this point
). The wire next to the thermostat is the thermocouple that was tied into a Fluke Meter for measuring the temperature.
Below is the Fluke Meter that was used to monitor the temperature, which is accurate to 1/10th of a degree.
Here is the data that I obtained, noting each shim was tested several times to obtain these average values:
It appears that with the 0.098” shim, the thermostat is barely closed. The 0.058” shim didn’t quite get me to where I wanted to be. The performance of the 0.075” shim, which seems to seal the thermostat better when it closes down again, will hopefully provide me the temperatures I am trying to achieve in the motor. However, if it is too cool the data will be used to make adjustments as necessary to get to my final goals.
So for now, when the motor is re-assembled in the spring, the 0.075” shim will be the first candidate and hopefully the last.
In the first photo the thermostat has been disassembled. You can see one of the shims that I made and the hole into which it is installed. The thickness of the shim will alter the opening point by lowering it, or as is the case if you get to approximately 0.100” thick shim, the thermostat will barely close.
One of the problems I ran into was how to measure data so it wasn’t subjective and I could repeat the test fairly well between the different shims and get a good comparison. After some messing around with the test, I decided to take the temperature at three points in the opening sequence. First, by hanging the thermostat such that the neck was downward, it was easy to trap air behind the rubber door that opens in the thermostat. The first data point would then be when the thermostat opened enough to release the trapped air. This doesn’t take much movement at all and you can barely see the rubber door move at all when this occurs since the movement is so slight. The second point of measurement would be when the rubber lip on the seal was even with the flat mounting surface of the thermostat (see the photo). Finally, I took a third measurement when the rubber lip was 0.2” from the same flat mounting surface. While this seems to be a precise number, it is actually the width of my flat screwdriver that I could hold in the water and use for a measuring tool. With one edge of the screwdriver against the flat mounting surface of the thermostat, when the lip was even with the other edge of the screwdriver blade that is when I wrote down the temperature.
Below is a photo of the shim installed prior to re-assembly of the thermostat.
Next was the method of heating up the thermostat so it was immersed in water. In the next photo you can see I bent up a coat hanger and hung it from a small stick across a large pot of water (my wife thinks I should be committed at this point
). The wire next to the thermostat is the thermocouple that was tied into a Fluke Meter for measuring the temperature.Below is the Fluke Meter that was used to monitor the temperature, which is accurate to 1/10th of a degree.
Here is the data that I obtained, noting each shim was tested several times to obtain these average values:
It appears that with the 0.098” shim, the thermostat is barely closed. The 0.058” shim didn’t quite get me to where I wanted to be. The performance of the 0.075” shim, which seems to seal the thermostat better when it closes down again, will hopefully provide me the temperatures I am trying to achieve in the motor. However, if it is too cool the data will be used to make adjustments as necessary to get to my final goals.
So for now, when the motor is re-assembled in the spring, the 0.075” shim will be the first candidate and hopefully the last.
