Today in 106 degree temperature, my '74 small block (which has a big-block DeWitt aluminum radiator and two fans) was running at 220 when my IR gun was pointed at the thermostat with the a/c on. Shouldn't it be lower with this radiator? Should I add one of those temp reducers such as "Water Wetter"? (Sorry for posting this also in the Tech section; I thought it should be in this section.)

 

What is it running at when you drive it????

Hopefully you have the front air dam installed to get more air into the radiator.

IF your thermostat housing is chrome...the IR guns do not read well off of reflective surfaces.

I would be more curious on what the temp of the radiator is a the upper hose connection area...and what the temp is at the lower hose connection....and see what the difference is when BOTH fans are running. When I do this test I black out the areas I am going to flash my IR gun at so I know it will read well.

Also...I do not know what type of thermostat you have in the engine. (high flow or regular design). I have always considered this so I know how fast the water is circulating.

You could try the "water wetter"...but I generally do not use that stuff due to I usually can get the system to work well without it.

Also...checking the obvious...making sure the coolant system holds pressure...the radiator cap is GOOD and being a 15 psi CLOSED SYSTEM cap....and the coolant quality is GOOD (either being the normal coolant or the Evans coolant) and I also drain the engine block at the block drains to just make sure there is not a bunch of crap laying in the bottom of the block that has never been drained and flushed out.

Also...I make sure that all of the required foam seal across the top of the radiator support are the and the ones that go between the radiator and radiator support. These are important.....which is why I asked what the temps were when driving.

For what it is worth...the 1984 to 1996 Corvette electric cooling fans do not come on until the coolant temp reaches 226-228 Fahrenheit. (The 1984 is slightly different)...but you get the idea.


DUB

 

Did you post this in "Technical" section, also? If so, it's a duplicate thread...

 

well without getting too intense if your car overheats at idle or runs hotter than you feel comfortable with, the reason is not enough air flow,

I am guessing since you have the dewitts ? "( which will cool your car ) you have the dual 11 spals which do leave a lot of radiator uncovered slightly wasted and if you run one fan for low both fans for high the space behind the off fan on low is also not being used fully, plus with one fan off the on fan will try to pull from least resistance which will be that off fans hole, so try both fans on at idle.

does the shroud of the dual fans have a seal around it so it's not leaking air and then when at speeds above 35-40 does it cool off, that is another nail in the coffin that it's low air flow at idle allowing it to get warmer.

if the temps creep up at high ways speeds factory seals and engine tuning could be effecting things,

water wetter does wonders in some and nothing in others but less than 10 bucks and helps condition lube and protect the system doesn't hurt anything to have it, I have always ran it.

 

YES...this is duplicate thread.

DUB

 

Took your advice and took some IR readings today. With an outside temp of 103, the temp gauge was at the mark between 100 and 210, the top of the thermostat housing was 224, top radiator hose 205, bottom hose 210, top of Dewitt radiator 139.
Based on these readings, how hot is my motor running? Do I need a new sending gauge? Thanks for any help.




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Originally from the city of "Wrestling's Living Legend"