The IR guns are good for an indicator but not always accurate unless calibrated to the surface they are reading. Better yet use a thermocouple and know for sure, Most cheap DVM's come with them

03/21/23 02:36 PM


Mike

so

I agree.

The old $99 top of line Sears Craftsman Infrared units had the added plug to compare its reading to thermocouples, and could adjust the ‘emissivity”.
similar to this unit:

https://www.amazon.com/Thermometer-...NXJFF8/ref=psdc_9931459011_t2_B00EXYPVG2

The way all things digital are declining in price I hope our low end cell phones will soon have thermographic ‘pit viper vision’ display at no added cost.

Even troubleshooting electrical devices it is useful to have “pit viper vision”.

Let me try this again. We all agree you can't have too much air flow, BUT, some think you can have too much coolant flow? Not so, just a bad rumor that will NEVER go away.

X

so

[i]
"Really. To much or fast flow rate may not give the radiator the time it needs to do its job. Thats not a rumor]" See, this is why it will never go away. The University of Minnesota has been the premier leader in the engineering of heat transfer since 1884.

No one in the study of heat transfer there at the U of M would agree with you. Either they are wrong, or the physics in your radiator are different than other places in the universe. I can't help but be sarcastic, as this has come up too many times. Think about it.....you can't have too much air flow, but you can have too much fluid flow??? I'm going with what they teach in engineering school.

Now, someone will come up with a story on how this guy did this or that and it proves I'm wrong. No, something else is going on in all of those cases as nobody gets to defy the laws of physics....anywhere in the universe. Good luck with the heat issue.

\
so

X

You last line there is perfect, and is exactly what happens when the fluid moves slowly.

But, it doesn't matter, no one ever wins an argument even in the face of facts. Have a good day.

X

I wonder if what you are seeing is because the fluid is not flowing slow enough to extract the heat? It would be interesting to see a comparison of AFR and EGT numbers as it was vs. how it is now ...

so

Faster is not better when it comes to engine coolant flow rate. The purpose of a radiator is to support heat transfer, which is a time-dependent process. As Flex-a-Lite explains, to move the heat from one medium to another (engine to coolant to radiator to atmosphere), the coolant has to remain in contact with a surface for heat transfer to take place. Moving fluid too quickly through an area can result in laminar flow, where the fluid forms layers. The layer closest to the surface moves slower than layers farther away from the surface. When this occurs, the layers act as insulators and the capacity to transfer heat is diminished. [/quote]

That is so wrong, if Flexalite says that I am glad I didn't buy their stuff. If you actually bothered to look up any heat transfer formulas you will see that time is not directly in the calculation but rather is expressed in the rate of flow (I.e. GPM) and in the calculations each increase in the rate of flow increases the rate of heat transfer. It matters not if it's the coolant or the air flow rates being considered.

I mean nobody suggests you turn the cooling fan slower so that the air "has time to transfer the heat". But if your supposition were true, it isn't, then it would stand to reason that slower airflow would help, it doesn't.

And there is no laminar flow in the cooling system EXCEPT in slow flow situations and in the radiator tubes. https://en.wikipedia.org/wiki/Laminar_flow

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[quote=NITROUSN]

X

[Last edited by NITROUSN; 06/23/23 02:04 PM/quote]

Totally agree, not worth the argument

OK, the U of M must be wrong, I'll get a hold of engineering and tell them they've been doing it all wrong and that they must have missed a decimal point in their studies years ago. Mean while the heat goes on!