Low temperature thermostat?

Grumpy Bear · June 23, 2021

On 8/23/2016 at 5:12 PM, O_J_Simpson said:

Please do it. We need someone to do it and report back how it affects carbon build up in GM's DI engines. Keep us informed please.

142,000 miles. Most of them on a Riesch Racing 170 F thermostat in an IPSCO housing. Upper hose in photo below.

Uses old school 55 mm small block thermostats.

It's a single cab and I have zero issues with winter heat even when -20 F. Fact is it will cook you like a turkey.

Zero issues with a quick warm ups. Yes they are lower peak temperatures. It is why you install them.

Tosses no codes.

Motor oil remains safely warm. Depending on load, 188 to 205 F. No oil sludging. No fuel build up.

Transmission runs cooler that a thermostat delete alone.

On a really hot day, that is over 95 F it will run a bit warmer on the water but only a few degrees. That is to say the thermostat gets and stays wide open and does not throttle.

It does not over cycle ever.

IF you get caught in something like accident traffic on a hot day it will get hot enough to cycle the fans. Water and oils can reach the low 200's (F).

If you turn on the AC the fans will kick on sooner and keep everything under 200 F.

I experiences no loss of economy. In fact it has improved with age.

Zero carbon issues. Actually lowered the KI r e t a r d. (Got censored LOL)

What else would you like to know?

At the time I did this mod Katech had not yet released this unit (174 F). This would be a cleaner installation perhaps.

https://gwatneyperformance.com/product/katech-160-degree-gen-5-lt-thermostat-kat-a7260/

Edited June 23, 2021 by Grumpy Bear

pokismoki · June 23, 2021

i'm using the Katec 175 thermostat, best upgrade for Hp for the $$$ spent. you can also try the cts-V stat 195 not much difference vs stock there.

not until i got my hptuners was i able to take advantage of it by adjusting the fans and telling the computer there is a 175 in the motor. a 160 will trip the fans to stay on all the time. if you run the 160, you need to purchase the hptuners upgraded OS so you can tune the fans below 195, otherwise convert the e-fans to a full time mechanical fan system

i would spend the money again, stock thermostat is too hot 212 and the radiator on this truck is way too small, we got v6 radiators, try getting the tow max package radiator

2015 High Miler · November 29, 2021

I’m in need of a new Tstat and have been looking to see if there is a benefit. Most say no but the last two posts appear to say otherwise. I have An HPTuner and credits. I live in central Texas and am not too worried about the heat but I am considering the 174 v the 160. Current mods are headers and ORY to single straight through muffler and a mild tune. The 174 seems a like a good option.

As far as heat builds horsepower in drag racing, I’ve never heard that unless it was on methanol.

@pokismoki @grumpybear would like to know more. Thanks

Grumpy Bear · November 29, 2021

11 hours ago, 2015 High Miler said:

I’m in need of a new Tstat and have been looking to see if there is a benefit. Most say no but the last two posts appear to say otherwise. I have An HPTuner and credits. I live in central Texas and am not too worried about the heat but I am considering the 174 v the 160. Current mods are headers and ORY to single straight through muffler and a mild tune. The 174 seems a like a good option.

As far as heat builds horsepower in drag racing, I’ve never heard that unless it was on methanol.

@pokismoki @grumpybear would like to know more. Thanks

Lane:

IMHO you would be best served using the 174 F thermostat. Not just because a tune isn't required.

Log your oil temperature. It needs to stay above 170 F fully warmed to limit oil nitration rate. Guys that drag race and use a 160 F stat don't worry about it because they change oil more often than the accelerated rate will cause damage. The sweet spot for oil is between 170 F and 190 F. Nitration is a concern below and oxidation above. These trucks have an oil cooler in the radiator tank so it IS tied to water temperature AND load. Why logging is a good idea or at least monitoring it. Anyone that believes you have to reach 212 F to get the water out has never hung dried cloths in the winter :crackup: . It just takes longer. OEM's run hotter because most drivers never hit full temp and if they do don't keep it at least an hour to dry it out. Silly really. Cloths in the dryer will not dry no matter how hot it is IF you don't run it long enough. D'ho!

My normal driving has the oil temp about 20 F hotter than water temperature BUT I can make that much higher running faster than MY normal. Each guys truck is different cause each guy is different. . Pepper is so quite I forgot I had her in M3 once leaving town and ran about 20 minutes at 55 mph near 5,000 rpm. Oil temp reached 250 F . Normally with my 170 F set up it runs about 190 - 193 F.

Grumpy

PS. That cooler thermostat may not reduce temperature at all IF your radiator is too small FOR THE USE (load) you are asking from it.

Edited November 29, 2021 by Grumpy Bear

2015 High Miler · November 30, 2021

Thank you, Marty. I def agree with your perspective but wanted to make sure it would not effect the vehicle negatively. Thanks again!

Sean Murray · February 18, 2022

My radiator is going right now so i bought an all aluminum from Radiator Express for $350 stock radiator replacmement. Part number for Radiator Express is 227796 my stock radiator is gm part 84207654. I am also opting to run just a little cooler and buying the gm part 12674634 thermostat which runs at 194 as apposed to 207 gm part 12674639. Good read on this thread.

pokismoki · February 22, 2022

On 2/18/2022 at 9:30 AM, Sean Murray said:

My radiator is going right now so i bought an all aluminum from Radiator Express for $350 stock radiator replacmement. Part number for Radiator Express is 227796 my stock radiator is gm part 84207654. I am also opting to run just a little cooler and buying the gm part 12674634 thermostat which runs at 194 as apposed to 207 gm part 12674639. Good read on this thread.

$350 sound a bit cheap is it thecorrect one, is that the larger6.2 radiator or the stock 5.3 unit?

I've seen the 6.2 rad is very pricy for the alloy upgrade, $900 from Moshimoto,,, not sure what GM wants for a factory 6.2 rad in plastic?

Edited February 22, 2022 by pokismoki

Grumpy Bear · February 22, 2022

On 2/18/2022 at 11:30 AM, Sean Murray said:

My radiator is going right now so i bought an all aluminum from Radiator Express for $350 stock radiator replacmement. Part number for Radiator Express is 227796 my stock radiator is gm part 84207654. I am also opting to run just a little cooler and buying the gm part 12674634 thermostat which runs at 194 as apposed to 207 gm part 12674639. Good read on this thread.

Thanks for the 411 on this. I see they have two radiators for my V6. One for tow and one for no tow. Wait for it!! :crackup:

Part number: 84186716 with tow. $456.58 OR>>>>>>>>>>>>>

23126398, 23126400, 23445975, 23394780, 23378658, 23445969, 84186716 (same part #) without tow for $217.64

And the difference is???? One has quick connects and the other does not. Yea, the part you can reuse from you old unit.

Oh wait, there is more. The standard V6 unit, tow or not, is 1" thick. The V8 non tow is .875 and tow 1" thick. V6 uses 6 plate stacked plate internal exchangers. The V8 uses tube, single row single pass exchangers. Same width and under a 1/2" difference in core height. Same hardware. The oil and transmission coolers are the SAME SIZE in each unit and differ only in the fitting size and style.

There is a reason Pepper behaves so nice. V8 sized towing radiator with stacked plate exchangers is standard on a no tow truck. WOW!!! And cheap too! Swap fittings from one side to the other. D'ho. Gotta love GM.

etex211 · May 12, 2022

Smokey Yunick studied the whole "water temp vs. horsepower" thing decades ago. His conclusion was that an engine makes the most horsepower when the water temp is around 230 degrees.

TJay74 · May 13, 2022

16 hours ago, etex211 said:

Smokey Yunick studied the whole "water temp vs. horsepower" thing decades ago. His conclusion was that an engine makes the most horsepower when the water temp is around 230 degrees.

And hence how outdated info and testing from "decades" ago is when it relates to much more modern engines and ECM's.

A LTx engine wont make more power at 230° of coolant temps, it will make less power due to the heat. The coolant temps alone will have the ECM pulling timing, couple that with it increasing the IAT temps and them pulling timing as well.

GM's Ltx engines already struggle to not detonate on 91, adding heat to them in the form of coolant temps and intake air temps will only cause the issue to be worse as the temps go up.

Grumpy Bear · May 13, 2022

I don't know if I would call Smokey's information outdated. It's more "Tune" specific TJay74. In fact your point is accurately based on this fact. Current technologies are not rigid their tune. They are adaptive as you note. And correct, a higher water temperature does all you say with all the results you list. Lower has the opposite effect to the degree the ECM is adaptive to and as someone noted in an earlier post you can exceed that tune with a 160 F if you live in the right area, thus climate. Why Katech and Reische Racing offer 174 / 170 F stats, respectively. 90% of the effect with zero need to retune.

In Smokey's day this was not true. Tunes of the day actually removed what little flexibility there was from the tune. Locking or removing the vacuum advance plate in the distributor for example. In his world, stock car racing asphalt oval, even the mechanical advance was locked or very limited. 10W40 was also the rule of the day and viscosity is heat dependent.

Got back 50 years before Smokey and advance was a leaver next to the steering wheel. Mixture was as well for some motors.

Smokey's information can be useful if applied to the right situation. No sir, not outdated. Just not a common need for it. It's been awhile since a Winston Cup Gen 1 SBC has been raced at Talladega.

pokismoki · May 14, 2022

On 5/13/2022 at 2:55 AM, TJay74 said:

And hence how outdated info and testing from "decades" ago is when it relates to much more modern engines and ECM's.

A LTx engine wont make more power at 230° of coolant temps, it will make less power due to the heat. The coolant temps alone will have the ECM pulling timing, couple that with it increasing the IAT temps and them pulling timing as well.

GM's Ltx engines already struggle to not detonate on 91, adding heat to them in the form of coolant temps and intake air temps will only cause the issue to be worse as the temps go up.

you sure he said that? your qoute might be a typo,

I know some modern drag racers prefer a high oil temp and lower coolant temp... for reduced oil viscosity and best detonation resistance

Smokey was working with carbs too, so the higher water temps improved atomization and fuel distribution in older v8's, our modern reverse flow heads and DI injection is apples to oranges comparision

Edited May 14, 2022 by pokismoki

Grumpy Bear · May 15, 2022

10 hours ago, pokismoki said:

I know some modern drag racers prefer a high oil temp and lower coolant temp... for reduced oil viscosity and best detonation resistance

Ones I know use 5W oil to begin with.

5WT RACE OIL - QUART

Popular for class racing in NHRA Stock and Super Stock
Also popular in NHRA Competition Eliminator

Modern racers know that the viscosity during the pass is what matters and that number when oil temps hardly hit 100F is high even in a 0W5.

10 hours ago, pokismoki said:

Smokey was working with carbs too, so the higher water temps improved atomization and fuel distribution in older v8's,

Yea, I was tuning drag race carbs then. We used fuel coolers and packed the manifold with dry ice. Change density.

There's enough going on past 6K rpm to keep the fuel vapor.

Smokey use heat and a lot of it in his "Hot Vapor Engines".

https://www.legendarycollectorcars.com/featured-vehicles/other-feature-cars/smokey-yunicks-hot-vapor-fiero-51-mpg-and-0-60-in-less-than-6-seconds-see-and-hear-it-run-in-our-exclusive-video/

customboss · May 15, 2022

Was sponsored by SYNERGYN from Dyson Oil Company for IMSA road racing and we successfully ran a 3w30 syn blend oil in an engine that required synthetic 15w50 or 20w50 according to GM engineers. Cut a lot of heat and allowed improved tuning.

Racing oil bottles vis specs are a joke. Meaning nothing. There is no such thing as WEIGHT in viscosity readings.

SYNERGYN was developed by Mike Dyson . Many of their products taken to next level by former Gulf Oil and Amsoil chemists.

https://wiki.anton-paar.com/en/sae-viscosity-grades/

https://www.machinerylubrication.com/Read/294/absolute-kinematic-viscosity

Grumpy Bear · May 15, 2022

42 minutes ago, customboss said:

There is no such thing as WEIGHT in viscosity readings.

Enough people believe it that marketing uses the term successfully. The rest of us know "Weight" when used like this means "Grade", An agreed viscosity spec at 100 C.

We use the terms heavy and light to describe the viscosity of a pancake batter. Sometimes stuff just sticks