Changing thermostat. Any firm recommendations?

[biomedtechguy]

Thermostat housing can be a pia. Mancini Billet solved mine.

I just came back from the "billet water neck" rabbit hole. There are so many! I'm liking the O ring variety. Any comments?
https://www.manciniracing.com/bispalwane.html

 

[biomedtechguy]

I normally run a 180, works well for most things. Running it hotter is better for the engine to a point. The issue with running it at 200 is you’ve lost 20 degrees of buffer if you get into a traffic jam situation. As far as the whole power thing, I tried several thermostats in my Dart. The car was a solid .1 faster with a 160 over a 180. Not that that would be the case for every application but, it tosses a wrench into the equation that you’re referring too. Intake temp plays a big role in power production. That’s why guys ice the intake at the track. You raise engine temp you raise the temp of the intake.

Agreed. My intake is the Edelbrock/Chrysler aluminum 6bbl intake, and aluminum absorbs and sheds heat faster than iron, so it would be susceptible to under hood and adjacent parts heat transfer. I do have the N96 hood to help.
I did the simple math, and 3% of 400 HP is "only" 12 horsepower. I have to take into account the air conditioning I'm about to add too.
I guess 180° will be a good place to start.

 

[RJRENTON]

Regarding hot restart, the 1st article I linked agrees.
Regarding power, and engine temperature, here's an excerpt:
In an engine, by reducing the difference in temperature between the combustion gas and the engine metal, you cut the loss (waste) of heat from the combustion gas, so more energy stays in the combustion gas, which is doing the work of pushing the piston. Smokey Yunick wrote in his highly-respected book Power Secrets: “Some guys go to great lengths to keep the engine temperature down … though the engine doesn’t overheat, they don’t realize that they’re putting energy (heat) into the cooling system that could be used to produce power at the crankshaft. Running the engine at 180 degrees will drop the overall horsepower by 2%-3%. For max power the cooling temp should be at least 200 degrees.”

I agree with your premise re temperature operating range. Smokey Yunick was a great engineer, engine developer, pioneer and an all around good guy.....true to his moniker "Best Damn Garage in Town", his passing was a genuine loss.
Its amazing the number of people, who contribute to this site, have no real knowledge of the fundamentals of thermodynamics and heat gain heat loss fundamentals relating to engine design and operating conditions, specifically with regard to cooling sydtem velocity, system pressure and circulating volumes. Too many times people just accept the word of some other person as gospel, who seem to accept the "They said rule" without substantiation. Just my opinion of course.
BOB RENTON

 

[biomedtechguy]

I'm reading your post and others in this thread now:
https://www.forbbodiesonly.com/mopa...rmarket-cooling-systems.34967/#post-910422315

 

[Hemirunner]

I normally run a 180, works well for most things. Running it hotter is better for the engine to a point. The issue with running it at 200 is you’ve lost 20 degrees of buffer if you get into a traffic jam situation. As far as the whole power thing, I tried several thermostats in my Dart. The car was a solid .1 faster with a 160 over a 180. Not that that would be the case for every application but, it tosses a wrench into the equation that you’re referring too. Intake temp plays a big role in power production. That’s why guys ice the intake at the track. You raise engine temp you raise the temp of the intake.

Agreed. The biggest issue, fuel boiling point, with the higher temps comes into play with a carb much earlier than EFI due to the lower fuel pressures. That’s always been the biggest challenge running at 200 degrees. I run a 180 stat and the car usually maintains 185-190ish.

 

[8formulas]

My 440 6 pack had a 160 thermostat in it. The tuning gurus insist on 195. So I listened. Installed a Robert Shaw 195 stat in it and my car HATED it. It ran so hot and pinged. I ordered a brand new Robert Shaw 160 and put it in. My engine runs awesome with this stat.

 

[biomedtechguy]

My 440 6 pack had a 160 thermostat in it. The tuning gurus insist on 195. So I listened. Installed a Robert Shaw 195 stat in it and my car HATED it. It ran so hot and pinged. I ordered a brand new Robert Shaw 160 and put it in. My engine runs awesome with this stat.

Good to know as I am about to install a Cold Case radiator. I have a Stant with the little hole in the frame of the stat, but I don't remember the temperature of it because I bought it a few years ago.
My concern was pinging being induced by a higher operating temperature. Not so concerned about under hood heat because my incomplete N96 setup leaves the hood scoop open, all the time.
I'd like to try 190 just to prevent the transfer of heat (power) from the combustion chambers to the coolant. That premise does make sense.
OTOH, I know cool days make for more power, so I don't want to overdo the running temps.

 

[8formulas]

I wouldn't go with stant. Just personal preference. They look cheaply made. In my opinion, Robert Shaw is the best. But that's just my opinion. Doesn't mean I'm right. Good luck.

 

[68 HEMI GTS]

Agreed. The biggest issue, fuel boiling point, with the higher temps comes into play with a carb much earlier than EFI due to the lower fuel pressures. That’s always been the biggest challenge running at 200 degrees. I run a 180 stat and the car usually maintains 185-190ish.

Absolutely, They make high RVP gas because the injected cars will handle it. It’s full of butane and other light & low octane components. They then use ethanol to get the octane back up so it’s a sellable product. Works fine in your new car but just plane sucks on these old big blocks. I find myself adding race gas to the roadrunner just to prevent vapor lock. Octane wise it doesn’t need it. Let’s not even talk about winter blend.

 

[70chall440]

I really like Safe T Thermostats, lock open if the car (engine) overheats, very handy, run them in all my cars.

 

[themechanic]

https://www.flowkoolerwaterpumps.co.../robertshaw-370-160-series-hi-flow-thermostat

 

[khryslerkid]

I just came back from the "billet water neck" rabbit hole. There are so many! I'm liking the O ring variety. Any comments?
https://www.manciniracing.com/bispalwane.html
View attachment 854556

I had this one from Mancini (not the O ring) and after two years it had warped .030.
https://www.manciniracing.com/mopv8throug1.html

My thread, and I went back to the factory housing...
https://www.forbbodiesonly.com/moparforum/threads/thermostat-housings.176744/page-2

As far as the temperature of a thermostat goes, my veiwpoint is that the engines ran cooler with the original leaded gas. 10% ethanol runs hotter so the recommended T-stat from your FSM might be too much. The census now days seems to be the 160* to 180* The 180* is what I run and it runs perfect when useing 10% 92 octane.

You have to remember that your choice will be the opening temperature. Once it's open, it's open. How hot your engine runs after that is dependent on the cooling system. Timing, fuel and your climate will also be a factor.

 

[biomedtechguy]

I wouldn't go with stant

FWIW it's some "premium" version, mentioned on this forum.

 

[khryslerkid]

FWIW it's some "premium" version, mentioned on this forum.

Superstat

https://www.summitracing.com/parts/snn-45478/

 

[Charger Fan]

Anybody know the 180F Stant Superstat part number for a 440 ?

 

[toolmanmike]

Anybody know the 180F Stant Superstat part number for a 440 ?

Look it up. Rockauto probably has the number.

 

[Demonic]

If you're having overheating problems at med to higher speed, it's likely a flow issue. the last Superstat I bought only had a 1" diameter opening. The EMP/Robetshaw ones are 1 7/16" diameter opening. They're worth it.

EMP/Stewart Components 301 EMP Stewart High Performance Thermostats | Summit Racing

Free Shipping - EMP Stewart High Performance Thermostats with qualifying orders of $109. Shop Thermostats, Mechanical at Summit Racing.

www.summitracing.com

 

[biomedtechguy]

If you're having overheating problems at med to higher speed, it's likely a flow issue. the last Superstat I bought only had a 1" diameter opening. The EMP/Robetshaw ones are 1 7/16" diameter opening. They're worth it.

http://[URL]https://www.summitracing.com/parts/emp-301

[/URL]

I don't think that fits a BB Mopar

 

[Demonic]

Correct, I tagged the wrong model. Model 304 and 305 cover Mopar BB.

 

[CudaChick1968]

I just came back from the "billet water neck" rabbit hole. There are so many! I'm liking the O ring variety. Any comments?
Billet Specialties Aluminum Water Neck
View attachment 854556

Yes.

Chuck the o ring and fill the groove with RTV silicone.