i dont care anymore its not my problem anyway
Cooling ? for FJ40
- Thread starter rjmcastle
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
ilike my new signature
I get what your trying to say, the only flaw in your argument is that you say the thermostat opens and closes. This is what allows the coolant to cool down in the radiator and then once the Tstat opens, the cool charge goes to the engine. If this is true, the coolant in the engine would be so hot that your would see the temp needle swing up and down. While most guages do not measure exact temps, some are, and I've yet seen one swing. Its plain and simply a regulator and not an open close valve.
i does not stay closed for a long time just enough to cool alittle. and i have a guage that you can tell when it opens and closes its that sensentive
2 core, crossflow, 180 stat, RV flex fan and a killer shroud ........you'll never have a problem.
here you go. the electric pusher is there because i already had the wires plus it wont hurt if i need it but have not used it yet
The thermostat does NOT "close to let the coolant in the radiator cool down, before allowing it to return to the engine block". A thermostat is a simple device that, once the coolant flowing past it reaches a certain temperature, it OPENS. IF the coolant drops back below that temperature, then the thermostat closes again. To put it simply, the thermostat cares not a whit (AKA "wasn't designed to worry about") "allowing the coolant sufficient time to cool in the radiator". (As has been stated before in this thread). The reason that it would close again (& why it is closed when you first start your engine) is to allow the coolant to stay inside the engine block, so that the engine block can attain, & maintain optimal operational temperature. This temperature is determined by having the correct temperature thermostat in there in the first place. As has been stated here, the optimal temperature is considered to be approx 195*. The "optimal temperature" is what the oil (viscosity at that temp), pump & filter are designed for, as well as fuel vaporization (through ambient heat flow into manifolds), etc. While these are also affected by other inputs (i.e. - intake gaining heat from exhaust manifold), in cases where people have headers installed, the heat comes from flowing from the engine block itself. Since the OP is in AZ, a slightly cooler thermostat MIGHT be in order, based only on the assumption that - it's pretty darned hot in AZ, so, he probably won't lose much, switching down to .... sayyyy ... a 180* thermostat.
In short, any argument that includes "the thermostat closes to allow coolant to cool in the radiator before returning to the engine block", is simply wrong. It's just a simple bi-metal valve.
BTW - I don't have any numbers to throw out, but, without a good shround, you lose a LOT of cooling capacity from your fan / radiator.
In short, any argument that includes "the thermostat closes to allow coolant to cool in the radiator before returning to the engine block", is simply wrong. It's just a simple bi-metal valve.
BTW - I don't have any numbers to throw out, but, without a good shround, you lose a LOT of cooling capacity from your fan / radiator.
The thermostat does NOT "close to let the coolant in the radiator cool down, before allowing it to return to the engine block". A thermostat is a simple device that, once the coolant flowing past it reaches a certain temperature, it OPENS. IF the coolant drops back below that temperature, then the thermostat closes again
then why does it close???it closes to slow the flow so it can cool down and the water in the block can asborb the heat before opening read what you said makes no cents you counterdicked yourself
then why does it close???it closes to slow the flow so it can cool down and the water in the block can asborb the heat before opening read what you said makes no cents you counterdicked yourself
OHHHHH..that sounds painfull
I think all parties replying are thinking alike but explaining it differently. my head hurts!!
Last edited:
- Thread starter
- #31
Wow i created a fun topic i guess. It got a little heated in here(pun intended) For some reason the two core runs alot cooler than the 4 core does not make sense to me. Have always run 160 stat only way to keep it cool in Az. So i guess the answer is to switch to 180. Would installing a fan clutch help gas mileage in any way?
dgangle
total rice
yes and that's one of the many reasons every vehicle from about the mid to late 70's comes with one. Other benefits are quieter, less parasitic drag and disengages so it doesn't actually become an air-damn, hindering airflow at higher vehicle speeds.
Yup, a whole bunch of complicated and hard understand items goind on there. Can wait to see where this discussion or the bad spelling goes now
Yup, a whole bunch of complicated and hard understand items goind on there. Can wait to see where this discussion or the bad spelling goes now
Last edited:
Not to join the cooling fray but I can tell you what has worked for me in the Florida heat.
Warmed up 383 with w core AL 2 core radiator (19X27) 7 blade clutch fan with a shroud. I have run the MKVIII electric and 7 blade flex and the 7 blade clutch. The single biggest factor is a shroud. With that either fan should work but the 7 blade clutch seemed to pull the most air. I also have a high volume water pump and thermostat.
Warmed up 383 with w core AL 2 core radiator (19X27) 7 blade clutch fan with a shroud. I have run the MKVIII electric and 7 blade flex and the 7 blade clutch. The single biggest factor is a shroud. With that either fan should work but the 7 blade clutch seemed to pull the most air. I also have a high volume water pump and thermostat.
pb4ugo
SILVER Star
Ditto. but I lean more to the engine requirements than the flow in the rad. The reason there is a T stat is to maintain engine operating temp. It closes & opens, or regulates because of what's going on w/ the engine, not the rad. The tstat doesn't know how much water is in the rad or what its temp is. It knows how hot the water is in the motor. A 195t stat starts to open @ 195, but is wide open some where around 205*.
Last edited:
It closes to slow/block the cooler fluid that is in the radiator from entering the motor in order to allow the motor to heat up to the optimum temp.
Once the motor starts going above the optimum temp, the thermostat opens up and allows the coolant in the radiator to enter the block bringing the block back down to the optimum operating temp.
The Thermostat will partially open in order to regulate the flow necessary to keep the engine at it's optimum temp (when the cooling system is operating properly) A cooling system that is too robust may never get up to operating temp. A cooling system that is not good enough may only overheat when it is VERY hot outside.
I had a 190* tstat fail in the open position on my 60. The damn thing would not heat up to save it's live when it was cold outside. During the summer it was just fine.
That makes no sense at all. By your logic if you completely removed the thermostat the motor would freeze. Nope, it will get very hot very quickly. You have to slow down the flow, keeping it in the radiator longer where the air and all those lovely little fins will remove heat from the coolant before returning it to the motor.
