[RTT]

Since it got hot here in So Cal (100+ degrees) my new 355 in my 84 has been running a little warm. 195 on the highway w/o AC, 200 with AC and 210-215 in stop and go with AC on. Radiator is a new Murray #433612.
I was going to swap my thermostat for a 160 but was advised not to by a mechanic not to. He thought maybe my current thermostat was defective. He advised me to put in a new 195 and I did that today. He was thinking that the coolant was traveling too fast thru the rad to cool off much.So with a new 195 thermostat today it was 100 degrees outside and she is now running 200-210 with or without the AC at all speeds. The clutch fan kicks in at 210 and cools it back down to 205. So i guess he may have been partially correct as it is now not spiking up to 215.
Should I actually try a 160 thermostat? Put an electric push fan in front of the rad? Try a high capacity radiator? Just leave it alone as it does not boil over. What would you guys do?
Thanks,
RTT

 

[HKDUP87]

Since it got hot here in So Cal (100+ degrees) my new 355 in my 84 has been running a little warm. 195 on the highway w/o AC, 200 with AC and 210-215 in stop and go with AC on. Radiator is a new Murray #433612.
I was going to swap my thermostat for a 160 but was advised not to by a mechanic not to. He thought maybe my current thermostat was defective. He advised me to put in a new 195 and I did that today. He was thinking that the coolant was traveling too fast thru the rad to cool off much.So with a new 195 thermostat today it was 100 degrees outside and she is now running 200-210 with or without the AC at all speeds. The clutch fan kicks in at 210 and cools it back down to 205. So i guess he may have been partially correct as it is now not spiking up to 215.
Should I actually try a 160 thermostat? Put an electric push fan in front of the rad? Try a high capacity radiator? Just leave it alone as it does not boil over. What would you guys do?
Thanks,
RTT

I put the 160 in my 305 and never no matter how hot loaded down and air on high it never hit 200. I didn't have any issues with the motor after putting it in but was told the engine needs to be at least 175 or so for the Ecm? I'd still be using it if I didn't swap motors. I'm running a 195 and today with air mine hit 213 at the highest but was around 205 most of the time. Is 215 bad for the motor? I think It's o.k. but not higher:dontknow::dontknow:


I HAVE A 160 IF YOU WANT TO TRY IT.

 

[69/84]

You can use the 160 thermostat and just fool the computer...
Go to Radio Shack and get a varaible resistor (Liner Taper Pot) 50K Ohm...

The stock CTS sensors change resistance based on temp. They are "Negative Coefficient" they drop in resistance as the temp rises...

If you wire the variable resistor in paralell with the sensor you will be able to adjust the voltage the computer sees and tell the computer it is at 190 and not the 160 you really have. you can then measure the value of the varable resistor and replace it with a small fixed value resistor. It's all VOODOO:nanawrench:

I did a tech inspection at a race one time where the driver wired this up using the seat belt switch...only told the computer it was cold when someone was in the drivers seat...Computer would then push the system Rich, giving him more power in a stock class:secret: Fun Stuff...

 

[woody31]

210 is not hot,,,, water boils at 212* add coolant and a 15psi cap and your good to go...
i would not be worried unless you get to 220+ and not coming down, i ran my wore out truck motor to 240 before and zero issues :beer:

 

[RTT]

Thanks for the input!
RTT

 

[mrblanche]

Engines run better at 195 than they do at 180. The reason most modern cars don't have temperature numbers on their temp gauges is we geezers get nervous at the current temperatures.

Once the thermostat opens, it doesn't matter what temperature it is. Your engine will likely run at 200 with a 160 in it. It sounds like the first thermostat might have been a little sticky, but the second one is working right. All a thermostat does is keep the water in the engine until it the engine is warm enough to run properly. After it opens, it does nothing but slow the water flow down to be sure it's not traveling through the cooling sytem too fast to absorb heat from the engine or lose heat to the radiator.

 

[fauxrs]

Engines run better at 195 than they do at 180. The reason most modern cars don't have temperature numbers on their temp gauges is we geezers get nervous at the current temperatures.

Once the thermostat opens, it doesn't matter what temperature it is. Your engine will likely run at 200 with a 160 in it. It sounds like the first thermostat might have been a little sticky, but the second one is working right. All a thermostat does is keep the water in the engine until it the engine is warm enough to run properly. After it opens, it does nothing but slow the water flow down to be sure it's not traveling through the cooling sytem too fast to absorb heat from the engine or lose heat to the radiator.

:agreed:

Also the temps noted by the OP are not outrageous temps for emissions equipped vehicles. Modern cars run at 225 all day long.

 

[mrblanche]

And "fooling" the computer will only make the emissions parts not work properly.

 

[darbysan]

For a reference, the TPI cars were set to turn the electric fan on at 235! Temps of 210-220 in the 100+ degree weather is normal, and as long as you have a good radiator cap, no issue.