What size T-stat should I use?

[sheetmetaldan]

I am replacing the water pump and adding a new radiator.There is no t-stat in my car right now,what size should I use 160*-180*. Would it make a big difference either way? I have a stock 318 no a/c with factory 4 blade fan with no cluch.Thanks

Also was going to use the rad cap off my 6 cyl rad I think it is a 7 pound cap will that be enough or do I need one that will hold more pressure?

 

[Chryco Psycho]

I would use the 180* T stat , the engine will usually warm uop quicker & run at that temp , with a 160 it will run above 180* anyway .
use a 14-16lb cap
I am sure you did something with this by now though .

 

[Cranky]

I've always used a 180. Besides, your oil works better when the temps are around 180-190....that is if you could get it to run 160. Also, heat is power. Too little heat isn't as good as the right amount and of course, too much is bad.

 

[R/T4speedconv]

I would use a 192 like the later emission engines used. The hotter you can run a engine the more power and economy from it. Of coarse too hot -above boiling point of your pressurized coolant) will cause wear problems and oil break down.

 

[Chryco Psycho]

We tested the new Chall with the 180* T stat & it gained 26 hp just dropping the temp from 195

 

[R/T4speedconv]

We tested the new Chall with the 180* T stat & it gained 26 hp just dropping the temp from 195

Could that be because the computer did not think it was up to temp and was running it a little richer to warm up?

 

[Chryco Psycho]

could be or running it slightly cooler got more cold air in & the engine added more fuel
same basic principal

 

[Big Jim]

Easy way to tell. If the gas mileage dropped off even slightly then yes the computer thinks the engine not to "operating temp" and still adding fuel...just my .02

 

[Chryco Psycho]

we didn't lose milage for sure on the 2010

 

[cv70chall]

you really don't need one if the car is in a warm climate- seeing as you never have to worry about warm-ups or the heater. It also allows for better water flow without restrictions. I would go with a 10lb cap- but nothing too strong or you'll bypass that safety feature the cap provides.

 

[moparleo]

ALWAYS install a thermostat. 180 degree with a 16lb cap. a 50/50 mix of new coolant and distilled water. This is not my opinion, it is a fact that the vehicle manufacturer requires. If it wasn't necessary they would not install it. They would save themselves millions of dollars every year. Remember that the vehicle manufacturers have spent millions of dollars over the years to optimize the safety and performance of your vehicle. Actually the number one reason for break downs in the whole country every year are cooling system related. We tend to take our cars performance for granted and think that the only attention it needs is an occasional oil change. While this is very important it is only one of many maintenance items that need regular attention.
The purpose of the radiator cap is to raise the pressure and therefore the boiling point of the coolant. Normal boiling point temp at sea level is 212 degrees. As mentioned earlier, higher operating temps increase efficiency and lower emissions. The engine tune specs are based on this information . A win, win.
Research this yourself. You can find all kinds of information on the internet and your owners manual.

 

[Chryco Psycho]

Except that running without will cause it to run hotter & overheat

 

[Fox Slaughter]

Run either 160-180. If you don't run one you can run the risk of never getting up to operating temp. Pistons aren't perfectly round. So you have blow by when they are cold. Once the engine warms up it will seal better. Fuel atomizes better at certain temps.

 

[Cranky]

I'm at sea level and don't see the need for a higher pressure cap and have been running 7 lbs for many years. My engines never go over 195-200 and the radiator doesn't ever see high pressure stresses so therefore they last longer. Just now swapped the original radiator in my 95 Dakota and the 2000 Durango still has it's original. Now I have no idea if my 66 Belvedere still has it's original but doubt it but ran it with what it came with in 88 until 98 but I never run with anything less than a 180 stat.