Thermostats - Reische vs Evenflo - vs Stock?

[JMR76]

If you've read my previous posts, you'll see the big difference was when the fans were set to turn on.  Mine are around 190 now, but I would actually prefer 185 with the 170 TS I'm using now. 

I tried both the 160 and 170 TS with LMS TS fan settings.  The 160 was all over the place for daily driving and actually hotter at the highest temp. 

The 170 wouldn't get as cold, but was more consistent and had a lower high temp.  I did a lot of testing and found that if the fans run too much or all the time, it kept the intake fluid too cold (radiating to the thermostat) therefore the thermostat would not open all the way soon enough causing the temps to spike.  With the 170 my car seems to like running between 174 to 184 most of the time.


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[metroplex]

If you've read my previous posts, you'll see the big difference was when the fans were set to turn on.  Mine are around 190 now, but I would actually prefer 185 with the 170 TS I'm using now. 

I tried both the 160 and 170 TS with LMS TS fan settings.  The 160 was all over the place for daily driving and actually hotter at the highest temp. 

I think the 160 Evenflo/LMS t-stat is just a modified hot-side t-stat, so the bypass part isn't the same. I thought I read the 160 would basically try to open/close repeatedly in certain conditions causing the erratic reading/behavior. The cold-side t-stat, like the factory unit or Reische 4D, has that bypass part that allows coolant to flow, and as it opens, the heat motor is shrouded by the bypass valve preventing the erratic behavior.

Do you find your fans to turn on more often with it set to 190?
I plan to keep it set to 200F initially and see how the ECT/CHT are affected by just the 170 t-stat. My theory is that the 170 t-stat will open up sooner and allow the cooling system to do its job without the use of the fans while the car is moving because it would be fully open by 190F and my setpoint is 200F. That would be confirmed if I see the ECT/CHT at speed about 10F or more colder than what I've seen with the stock (190-195F ECT in single digit winter temps). So at the track, as the car is moving down the dragstrip, airflow and the cooling system should keep the engine colder than before - without the use of the fans. But that's just something I need to look into with data.

[MiWiAu]

My theory is that the 170 t-stat will open up sooner and allow the cooling system to do its job without the use of the fans while the car is moving because it would be fully open by 190F and my setpoint is 200F.

Also, don't overlook the fact that a lower temp stat will stay open longer, allowing for lower coolant temps, during periods of no load (coasting).

As I said in my previous post, coasting from 70MPH to 0 over 22 seconds allowed my coolant temp to drop from 185F to 171F (with a 170 stat). The OE unit would have closed earlier, keeping temps closer to 180F leaving the coolant with less ability to absorb additional heat.



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[JMR76]

If you've read my previous posts, you'll see the big difference was when the fans were set to turn on.  Mine are around 190 now, but I would actually prefer 185 with the 170 TS I'm using now. 

I tried both the 160 and 170 TS with LMS TS fan settings.  The 160 was all over the place for daily driving and actually hotter at the highest temp. 

I think the 160 Evenflo/LMS t-stat is just a modified hot-side t-stat, so the bypass part isn't the same. I thought I read the 160 would basically try to open/close repeatedly in certain conditions causing the erratic reading/behavior. The cold-side t-stat, like the factory unit or Reische 4D, has that bypass part that allows coolant to flow, and as it opens, the heat motor is shrouded by the bypass valve preventing the erratic behavior.

Do you find your fans to turn on more often with it set to 190?
I plan to keep it set to 200F initially and see how the ECT/CHT are affected by just the 170 t-stat. My theory is that the 170 t-stat will open up sooner and allow the cooling system to do its job without the use of the fans while the car is moving because it would be fully open by 190F and my setpoint is 200F. That would be confirmed if I see the ECT/CHT at speed about 10F or more colder than what I've seen with the stock (190-195F ECT in single digit winter temps). So at the track, as the car is moving down the dragstrip, airflow and the cooling system should keep the engine colder than before - without the use of the fans. But that's just something I need to look into with data.

The 190F fan setting seems to work good.  The original settings were lower, around 180 I think and my fans would pretty much always run.  Even more in the winter which was strange. 

The fans don't run a lot with the 170F TS and 190F fan settings, allowing the coolant to flow and cool more by itself.

I experience issues when the fan settings are too low and turn on before the TS is fully open.  Seems to get stuck at a higher engine temp as the intake flow is ice cold before it opens. 


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[JMR76]

Also, from my testing, the 170F TS likes to run between 172-184F without fans.  So with the 190F  fan settings the fans don't run as much. 

I would seriously want fans to start at 185 and off around 175 but they wouldn't do that at this time.  I am still happy with the 190F settings though.  At this setting, the fans barely run during the winter at all.

If your worried about the fans running all the time, I would ask LMS to set them at 190 first.  If your not satisfied you could them go to 200F.

PS. Don't use the 160F TS Unless your only tracking the car.  It's a good quality TS, but not the proper one for our vehicle.  The Reiche 170F is the one I decided to keep after numerous testing.  You can also PM me if you have more questions. 


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[metroplex]

Thanks! I did research on the cold side vs hot side issue and agree that the Reische is the better design as it matches the oem tstat. I have been running my own tune so it's not hard for me to change the setpoint setting. What does your ect tend to read in the summer without the fans running?

[JMR76]

Thanks! I did research on the cold side vs hot side issue and agree that the Reische is the better design as it matches the oem tstat. I have been running my own tune so it's not hard for me to change the setpoint setting. What does your ect tend to read in the summer without the fans running?

If I'm cruising my ect usually stays around 180-185 without fans.  Letting off gas and running downhill it'll dip down around 172.  Idling and heavy traffic it'll go up over 190 after a while and the fans kick in and cool it right back down.


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[metroplex]

My 4D arrived and I tested it. It starts to open at 164F and is fully open by 176F. Does this sound typical?

[MiWiAu]

My 4D arrived and I tested it. It starts to open at 164F and is fully open by 176F. Does this sound typical?

Sounds reasonable for a 170 stat. I'm guessing this was in a pot of water, so you could observe? Does your thermometer read 212 in boiling water and 32 in ice water?

Depending on the sensitivity of your thermometer, you will probably also pick up a temp difference at the bottom of the pot (closer to the heating element) vs the surface of the water.

Once it opens, you could remove the pot from heat and let the water cool and see when it fully closes again.


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[metroplex]

I installed it, took just over 30 minutes. I extracted all of the degas bottle coolant (about 0.5-0.75 gal, it's a fairly large bottle for what appears to be a small reservoir) and not much coolant came out of the housing area. The stock t-stat was really jammed in the housing/block and was probably the hardest part of the whole procedure. The O-ring gasket looks to be the same RG-571 that we use in the old 2V modulars and the 3V modulars.

Mike, yea I just used a pot of water. I did repeat the test and got about the same results.

The stock factory t-stat had a little plunger bleeder valve while the Reische did not have one. The stock t-stat also had some type of rubber coating on the internal valve of the t-stat.

[metroplex]

I wanted to drive the car for several days to help bleed it out completely before datalogging. After doing some normal drives (cruising) and some WOT runs, the data is fairly clear. The cylinder head temp is on average 10 degrees cooler than before using the same fan settings (as we are expecting). It seems the faster the engine runs, the cooler the cylinder head temps become. There's also a fairly dramatic change in knock retard. There's at least a 2 degree reduction in knock retard.

[derfdog15]

Glad it worked out for ya! And that you have seen the results I and others have seen.

With a 2 degree KR decrease, what was your normal KR before? I didn't see that major of a KR change, but I also run E20 and have minimal KR anyways, so KR was not really changed for me (since I had almost none already)