resdoggie

I believe he is referring to the thermostat's valve modulation which is controlling the flow rate in conjunction with the pump speed controlled by the engines rpm. You can't have zero flow or engine will over heat. We know that. But you can't run an engine without a TS either and expect the coolant to remain at a desired temp of 180*F when its -20F outside or 90F. Not gonna happen. So, control of the coolant flow is part of the equation. So, does it need to be slow or fast? How well can the radiator absorb the heat of the coolant and transfer that heat to the air flowing through the core? Design of the rad for the expected load must be sized properly. Too small a rad and it will over heat the engine regardless of the speed of the coolant flow because the rad can't reject enough heat fast enough. I think he was going to the extreme on air passing through the core.

resdoggie

I answered your question. Whatever hose you have is rigid enough to not collapse without a spring. Others have noted that newer hoses have the required rigidity.

lionelhutz

No, if you're claiming to debunk myth then there is no excuse for writing garbage such as "coolant never has a chance to park in the radiator long enough to give up heat energy to the atmosphere".

It's an awfully big jump to get from what was written to the thermostat is need to maintain a constant engine temperature. Huge jump.

Talking practical applications, meaning typical axial fans and partially open impeller water pumps it's not possible to flow enough to cause negative effects. I've done various testing of power semiconductor devices with heat sinks and have never managed to produce so much airflow that the device temperature started to climb again. As you ramp up the airflow you do reach a point where adding airflow does little to produce more cooling - ie diminishing returns - but you never reach a point where the cooling suddenly drops and the device starts running significantly hotter.

resdoggie

Sorry, I'm not following what your saying.

I wasn't grasping the increased air flow he mentioned except that maybe the fins all have to be perfectly aligned and straight between the tubes or turbulence will occur reducing effective cooling. He says he's an 'aeronautical' engineer but he's not the guy who wrote the article. Maybe he's going a bit/lot overboard there. I am in full agreement with your comments on cooling heat sinks.

lionelhutz

That the statement "coolant never has a chance to park in the radiator long enough to give up heat energy to the atmosphere" is complete and utter hogwash. The statement also has nothing to do with the thermostat being used to regulate the engine temperature, hence it's a huge jump to say that's what the quoted statement really meant. I can't make it much clearer.

Torqued Off

Thank you......finally some reasonable clarification and logic.

Richard454

Jeff-

What if your Dewitt's flows better than a stock radiator -
So when the pump pulls hard- the flow is not restricted by the radiator thus keeping the hose from collapsing.


With the video I posted-it's plainly showing the hose can collapse.... If it continues to collapse - the hose more than likely fatigue and eventually could pose a problem.

I have also spent the extra money on a quality Dewitt's radiator- and for less than what half a gallon of antifreeze costs- it makes sense to add the spring...

It's very inexpensive insurance.

Richard

resdoggie

I never said that. I concurred with the author of the 9 myths but not necessarily word for word and some of the replies were out to lunch on how a cooling system works and the purpose of a TS. The TS is a valve that varies between open, shut and any point in between which regulates the temperature of the coolant by varying the flow of coolant through the radiator for the desired operating temp. Pretty darn simple.

resdoggie

As others have also mentioned, the cost for an inner spring is cheap insurance whether needed or not.

Big2Bird

48 posts to circle back to my answer in post #2.

lionelhutz

You're really not keeping up. The text is from the article. When you say you agree with the article are you seriously saying you agree with that quoted hogwash?

Just to make it clear, below is the authors complete text about this thermostat "myth".


The whole paragraph is simply repeating the wives tale which says coolant flows so fast through the radiator without a thermostat that it doesn't cool.

There is ABSOLUTELY nothing there about the thermostat regulating the engine temperature. Nothing saying the thermostat increasing flow when more cooling is required and reducing flow when less cooling is required. The thermostat works by opening further and increasing the flow as more cooling is required, not slowing it down so the coolant has more time in the radiator to "give up heat energy to the atmosphere".

He then spouts more stupidity when saying the airflow can't be too fast or it won't work as well as slower moving air.

marshal135

My new lower non GM stamped hose from Ecklers came today for my '68 BB.
It has a spring inside.
Preventive medicine I guess?
Marshal

Big2Bird

From the Stewart water pump web site:

Thermostats & Restrictors
We strongly recommend NEVER using a restrictor: they decrease coolant flow and ultimately inhibit cooling.

For applications requiring a thermostat to keep the engine at operating temperature, we recommend using a Stewart/Robertshaw high flow thermostat. This thermostat does not restrict flow when open. The Stewart/ Robertshaw thermostat enhances the performance of the cooling system, using any style of water pump. However, the Stewart Stage 1 high-flow water pump may require this thermostat to operate properly, and Stewart Stage 2, 3, and 4 water pumps simply will NOT operate with a regular thermostat because these pumps have no internal bypasses.

Stewart further modifies its thermostat by machining three 3/16" bypass holes directly in the poppet valve, which allows some coolant to bypass the thermostat even when closed. This modification does result in the engine taking slightly longer to reach operating temperature in cold weather, but it allows the thermostat to function properly when using a high flow water pump at high engine RPM.

A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.

Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap's rating and force coolant out, resulting in an overheated engine. Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.

Tom's '07 Monty

You guys are great! I have on the sight the past couple of weeks as I play (fix?) with two of my friends' Vettes. There is a lot of great Vette people out there who love to share their vast, in depth experience. And 99% of the time, it is without putting someone down (not necessarily the same of C7 forum). Thanks for all you do.

kanvasman

Can't believe I got sucked into 54 posts about a spring. I actually am putting my cooling system together right now and had the new hose and the old spring sitting there wondering what to do with it. It's settled, put the old spring in the new hose. I actually might get another spring and put it in the upper hose...just in case...LOL. Great thread and good info, like a panel on the talk shows. lots of talking but no one ever changes their mind. But they never say " you drive like a girl". That is the quote of the month. Thanks for the fun.

marshal135

Yeah the springy thingy got pummeled to death.
Just put it in if ya got it.
Marshal

resdoggie

"One of the greatest — or perhaps worst — cooling system myths is that you can remove your thermostat to eliminate overheating. This will only add insult to injury! When coolant never has a chance to give up heat via the radiator, it gets hotter and hotter, especially if you’re stuck in traffic. And even on the open road, coolant never has a chance to park in the radiator long enough to give up heat energy to the atmosphere."

You explain what he means when he says "park".

"He then spouts more stupidity when saying the airflow can't be too fast or it won't work as well as slower moving air."

He's referring to laminar vs turbulent flow when applied to air flow across the tubes and fins. He also referred this to electric fans attached to the radiator where air velocity would be quite a bit higher due to proximity than what a mechanical fan in a shroud could produce. What characteristic of air flow would you choose? Laminar or turbulent? Or do you just believe there is no such thing as a Reynold's number that determines when a fluid changes from laminar to turbulent flow? You come across to me as saying it can't happen.

"There is ABSOLUTELY nothing there about the thermostat regulating the engine temperature."

Um, because it's not a myth unless you think it is. If so, explain your myth.

I did go back and read his article and all the replies more thoroughly. The respondents who supported the article had better arguments over the naysayers when applying physics and thermodynamics in their explanations, imo. But if someone doesn't have any education and/or training in science/engineering, it would be difficult to form an opinion on who may be right or who may be wrong. Should others actually take the time to read the entire article and replies, you'll see that as simple as a cooling system appears, there is a lot of engineering that goes into its design.

lionelhutz

LOL, you can believe whatever you want, but it doesn't change the fact that the authors claims stating the coolant has to be moved slowly through the rad to be capable of cooling the engine are wrong. He even says parked which could implies the coolant needs to be stopped in the radiator for a period of time to be capable of cooling. I doubt he really meant stopped, but it certainly is implying it has to be kept there for a long period for anything to happen.

Turbulent airflow of course. Turbulence cools better, this is well documented by everyone who has an actual clue about such things. Basically, when you cause turbulence, the air molecules are all swirling around so they can come into direct contact with the surface and absorb heat directly from the surface. Luckily, current radiator designs pretty much guarantee turbulent airflow any time there is airflow from a fan or the road.

Laminar flow results in very little flow right against the surface. So, the heat has to be transferred by conduction from the still air molecules at the surface to the moving air molecules further away from the surface, which is a rather inefficient way to transfer the heat.

Here, this sums it up nicely.

http://www.advantageengineering.com/...tageFYI156.php


Huh? You're not making any sense here. The statement I wrote tat you quoted says the article contains nothing in the text which described the thermostat as a device that regulates the engine temperature. You're saying this statement is a myth? Huh? Can you quote the authors text that does say this?


I quit reading the comments when the "red hot space shuttle" was brought up as an argument. That was as much stupidity as I can stand.

If you want to get the truth, then go to an engineering website where answers are posted. You'll usually find people who actually know what they are talking about there, instead of comparing the airflow through a radiator with a "red hot space shuttle".

Torqued Off

In a very related question......does this spring go the entire distance from the outlet of the radiator to the inlet of the water pump? I believe it is shorter than that, based on pictures of the spring I have seen, sooooo if it does not fill the hose the entire way, why does the hose not collapse in the area without the spring?

Richard454

I'm glad both "resdoggie" and I can make you laugh-

As Laughter is Good for the Soul....


Beating a dead horse is not....