I don't know what temp the stock thermostat is. Is there a benefit to installing a lower temp thermostat? If so, what should be expected? I was looking at some thermostats in the Summit Racing catalog and I believe MTS offers one as well.

In reading what others have tried, it seems that each set up likes a different operating temperature. Some have found that their engine likes to run cool....in the 180-190 range. Others have said that theirs seems to like the temp up in the 200-210 area. I haven't heard too many people that have said their 472/500 Caddy likes to run cooler than 170.
If you decide to change the thermostat to a different temp range, you'll probably need to change the timing also.
Big block Cadillac termostats are not the same as other GM thermostats. Make sure that you get one with the cup on the bottom side for the by-pass. I know the FlowKooler web site has a picture of one.

Thanks for the info. What is the stock operating temp?

Stock temperature is 180.

I thought some of the later 472/500 had a 195 degree thermostat stock. :bonkers:

I believe your right cadrolay. If memory serves, they switched to 195 degree stat around 1974.

I have had to deal with a thermostat being too low.
The water did not have enough time to remain in the radiator to release heat.
So, we installed a higher temp thermostat to LOWER the water temp.

Science says that shouldn't work..

I have had to deal with a thermostat being too low.
The water did not have enough time to remain in the radiator to release heat.
So, we installed a higher temp thermostat to LOWER the water temp.
Sounds like there was no thermostat there at all.....?

The lower temp thermostat was opening and staying open, allowing the water to circulate too quickly thru the radiator, which didn't allow the heat to be exchanged.
Sounds strange, but it is not the first I have heard of it.

The increased volume of water through the radiator would've made up for the lower time of the water being in contact with the radiator. The radiator is able to transfer the same amount of heat no matter how much water is going through it.

True, the radiator is able to transfer the heat, but if the water moves TOO quickly the radiator is not allowed to remove the heat.
If the water is pushed thru the radiator too quickly, the net effect is putting hot water back into the block and the cycle continues.
The coolant has to remain in the radiator long enough to transfer the heat.
JMHO.

"We" had this discussion on a Chevy truck site, so it may apply more to the flat faced trucks.
I also have had personal experience of a 160 thermostat running at 195-200, and a 180 running at 180.
Same system, same day.
I guess it also depends on your individual system.
? ?

Bah. Maybe religion can explain it.

Not to get back to the original discussion

use the one flowcooler offers they are leaps and bounds ahead of the rest and outlast the rest 2-1 :thumbsup:

TorqueINC

The increased volume of water through the radiator would've made up for the lower time of the water being in contact with the radiator. The radiator is able to transfer the same amount of heat no matter how much water is going through it.

Ok... think of it this way. Your in your car, nice and warm. Outside the car its really cold and you want to get into your house. Do you run or walk? You run, because if you walk (move slower :p) your going to lose more heat. If you run, theres less time for the heat to escape your body! :banghead2

I just realized that was a really poor example... sort of. :helpless:

But a lower or higher temp thermostat doesn't effect how fast the coolant flows. It only determines at what temp it starts to flow.

All I meant by the more volume was that with the thermostat opening at a lower temp the coolant starts circulating sooner than a high temp t'stat.

Ok... think of it this way. Your in your car, nice and warm. Outside the car its really cold and you want to get into your house. Do you run or walk? You run, because if you walk (move slower :p) your going to lose more heat. If you run, theres less time for the heat to escape your body! :banghead2

Yeah, but if there's 2 of you and you run 1.5 times as fast as you walk, you would lose more heat overall.

All I meant by the more volume was that with the thermostat opening at a lower temp the coolant starts circulating sooner than a high temp t'stat.

Yeah, but if there's 2 of you and you run 1.5 times as fast as you walk, you would lose more heat overall.

I'm still putting a 160 deg thermostat in my rebuild. Once any thermo is full open the flow rate is the same, so once the coolant temp gets to the point where the thermo if full open, the coolant can't flow any faster. Logic dictates that if a thermo reaches full flow at 160 and another at 180 (actually the full open is higher but that's not the point) the lower temp of the coolant with the 160 thermo will enter the radiator "cooler" than the 180 thermo coolant. (I'm the master at logic, even Mr spock bows to me :worship:)

Also it's HOT here in FL, I can watch the gauge go up in the summer, even on the open road:holycrap:

fact. if the thermostat is closed then the water in the radiator is exposed to cooler temps longer.
fact. this is the reason the thermostat was invented.
opinion. using a thermostat that is always open is like screwing for chastity it just dosn't work.