Picked up a New Trans pan

[jpr38057]

Originally Posted by Mark Kovalsky That is an AMAZING post! I am continually amazed by what people will post in a public forum. I'm not just working from theories. I've tested this stuff. I have run cooling tests both in a wind tunnel and on the road with HUNDREDS of thermocouples measuring temperatures all over and under the truck. All you have is your theories on how things should work in your world. Amazing. And it amazes me that engineers like to put people down because they have tested it. (refer to my prior post) Common sense tells us that air flow cools things. A radiator doesn't do much good without air flowing across it or is my common sense wrong on that?

[Stewart_H]

Originally Posted by jpr38057

And it amazes me that engineers like to put people down because they have tested it. (refer to my prior post) Common sense tells us that air flow cools things. A radiator doesn't do much good without air flowing across it or is my common sense wrong on that?

Using sarcasm to illustrate a point or rebut someone, in my opinion, isn't a put down.

Mark hasn't put anyone down, he has tried to impart his experience and knowledge, but some people are (in my opinion) arguing their point using anecdotal evidence from examples that don't apply to the principles of heat transfer as it relates to the 4R100, based on all the experience and empirical data Mark has collected.

Besides, if the Marine who started this post want to put a Mag trans pan on his ride, I'd be the first one to help him out!

Gotta appreciate a man who is willing to give the ultimate sacrifice for our country.



Stewart

[EXv10]

Originally Posted by Digger 5

I guess my gauge must have been wrong when it showed a 10 degree difference when I was drag racing (after adding the finned/tubed trans pan).

I'm not saying I expect a huge difference with the OP changes pans...but ZERO?

I agree, I meant the exhaust temperature won't affect the pan temperature at 65 MPH. Of course it will run cooler somewhat.

[EXv10]

Originally Posted by Mark Kovalsky

That is an AMAZING post! I am continually amazed by what people will post in a public forum.

I'm not just working from theories. I've tested this stuff. I have run cooling tests both in a wind tunnel and on the road with HUNDREDS of thermocouples measuring temperatures all over and under the truck.

All you have is your theories on how things should work in your world. Amazing.

Actually it is pretty obvious; if air is rushing under the truck at 65 MPH the heat from the exhaust is not going to affect the temperature of the trans pan. Have you ever ridden a motorcycle? All the air that comes at you when it is colder than you are takes the heat from you and puts it behind you. It's called convection. The pan will obviously run cooler due to this condition but don't think it would be by much therefore I don't think it is worth having especially when you can't see it and the addition of another oil cooler would be a much better idea. What you said originally was "have you ever stood next to a car when it is idling and felt the heat from the exhaust?" ; well, common sense will tell you this has nothing to do with anything. Common sense would have told you that cold air will shrink and harden a rubber o-ring like the one in the Challenger space ship.............get it?

[X-Hibition]

I can't take the pressure, I'm vain.

I bought the Mag-Hytec front diff cover, rear diff cover, and trans pan because I'm vain. I did it for looks. I'm shallow. I have no engineering to back me up. They look marvelous. Even in the box.

Don't hate me because I'm beautiful...

[Mark Kovalsky]

Originally Posted by jpr38057

Common sense tells us that air flow cools things.

That is NOT always true. If the air is the same temperature or hotter than what you want to cool it will NOT cool. Just because you like to believe that there is cool air under the truck doesn't make it so.

Originally Posted by jpr38057

A radiator doesn't do much good without air flowing across it or is my common sense wrong on that?

If the air going across the radiator was the same temperature or hotter than the radiator then no, it would NOT cool the radiator. That's just common sense with a good dose of heat transfer.

You should at least know the basics of heat transfer for this discussion. The basic part that you seem to be missing is if the air is as hot or hotter than what you want to cool it does not matter how much air is flowing past, it will NOT cool.

[Mark Kovalsky]

Originally Posted by X-Hibition

They look marvelous.

Yes, they do look marvelous. Their workmanship is top rate.

I think that's the best reason to buy one. They DO make the truck look better.

[njneer1]

I am not a transmission engineer either.But I know this is a function of material, material thickness, surface area and airflow. I would like to see a real life comparison between the two. Good thread, lots of good opinions. The facts would tell the story.

[X-Hibition]

Thank you Mark for my vindication.

I've read and enjoyed your informative posts in the past and have appreciated them.

But you are sooooooooooooooooooooo wrong on this one...

Don't be a stranger.

[GregN]

Originally Posted by Mark Kovalsky

I guess my college heat transfer text books were wrong about that. You would know better than those that have developed the science of heat transfer. I'll tell them they are wrong and need to correct their theories to match yours.

They may not be wrong, but possibly out of date. Maybe you should go back to the basics...Heat transfer - Wikipedia, the free encyclopedia "Where there is a temperature difference between objects in proximity, heat transfer between them can never be stopped; it can only be slowed.". But, according to your textbooks, I can tow the max load for 100 miles, get out and feel the transmission pan and it will be at ambient temperature? They are just "theories" not laws of thermodynamics? If you are saying the ATF is in laminar flow, then the fluid could form a boundary and SLOW the convective heat transfer rate, but not completely eliminate it.

Originally Posted by Mark Kovalsky

I also suppose the data I collected when I was a transmission cooling engineer was wrong. I'll let the person that took over for me when I left know that the testing was wrong.

Yeah, that would probably be a good idea, you can use me as a reference if they have any other questions!! Just a joke (believe it or not, I do have a sense of humor)

Originally Posted by Mark Kovalsky

The principle is NOT the same. A differential has no cooling except what transfers out of the housing. In that case the amount of cooling that is added by a finned pan is significant - because there is so little other cooling.

How is this not the same principle? Convective Heat Transfer...It's the Law!!!

Originally Posted by Mark Kovalsky

The bottom line is that I really don't care what pan anyone runs. I just thought people would want to know an informed opinion on how much cooling is possible through a pan. Now I know that most of you don't want to be told anything that is different from your beliefs, whether there is data to back it or not.

I have not seen any data that proves otherwise yet!

I understand that you don't want people to think that by replacing their trans pan with a finned one will significantly reduce ATF temperature, but it won't hurt. There aren't really any better options than adding an external oil cooler, I won't dispute that.

I should have learned my lesson with dealing with the engineers at work (or the Chemical Engineer girlfriend (she studied heat transfer for her diploma)), there really isn't any point in arguing with an Engineer. I can never seem to make a good enough argument. So, I give....UNCLE.... I am hanging my hat up on this thread...It has been fun guys. I don't want to be accused of inciting a riot to defend something that I really don't care that much about.

Remember: Life is Good (except for the economy and the government takeover)!

Later,

Greg

[X-Hibition]

This is all Devil Dog's fault, he started this thread...

Have you installed it yet?

[GregN]

Originally Posted by X-Hibition

This is all Devil Dog's fault, he started this thread...

Have you installed it yet?

I agree!

I am the person who always seems to turn the knife to make things exciting.

Oh...Whoops...I am done with this thread...Yeah...Done...Now....NO.....Now!!

[X-Hibition]

O.K. Devil Dog, you were supposed to do this install yesterday. Are you done? Does it run cooler...? Heh Heh

See what you have done to Greg and everyone else? Turned everyone in to Haters.

[Husky44]

Mark:

Since I'm one of the ones who contributed to the inflammation of this thread, let me jump in to see if I can help salvage it.

I was wise enough to acknowledge that your science might trump my common sense, so don't flame me yet.

My common sense and limited science classes lead me to believe that "all else being equal" (there's the economist in me showing), tranny fluid in the finned, larger capacity aftermarket pan would be cooler than in a stock pan. My (admittedly uneducated reasoning):

1) More fluid should result in the ability to disperse the same amount of heat over more volume, resulting in lower temps.

2) Larger, finned pan results in more surface area exposed to presumably cooler ambient temperatures outside the pan than the fluid inside (more on that assumption in #3), which should result in a cooling effect occurring to the pan and presumably to the fluid inside

3) Assumption that while the vehicle is moving, the airflow under the vehicle, although affected somewhat by heat from the engine compartment and exhaust, would result in ambient temperatures lower than the outer surface of the pan (and the fluid inside it).

4) The fluid in the pan isn't stationary, but circulating in some fashion, which in my admittedly uneducated mind would tend to offset the insulating layer you initially described (in other words, I can see that occurring in a static fluid, but would think it wouldn't occur in fluid that should be moving).

Those are my reasons for expecting the aftermarket pan to result in cooler tranny fluid temps. Help me understand where I'm off track?

Not questioning your accuracy, just trying to understand "why?".

Thanks!

[EXv10]

Originally Posted by Mark Kovalsky

Be prepared to be surprised.

Have you ever stood next to your truck while it was hot and running? Feel the HOT air coming from underneath the truck? How is all that hot air under the truck going to cool the pan? Answer: It won't.

Another problem is that there is nothing moving the fluid right at the pan surface. It develops a boundary layer of fluid that acts as an insulator. The hot fluid doesn't get to the pan surface, so it doesn't get cooled.

Big pans look nice, but don't do anything useful.

The same hot air that you think if affecting the finned pan is also affecting the stock pan but the real heat comes from the engine and tranny friction and while ambient heat from the exhaust may play a small role when the truck is stopped that whole theory goes out the window at 65 MPH. So, when air is moving under the vehicle the larger finned pan must experience some extra cooling even though I doubt if it would be much. And nothing moving at the bottom of the pan? How do you know, have you ever been inside one? I would suspect a lot is moving and even if it wasn't the heat would migrate rapidly throughout the pan. I guess I should make sure everything is at the bottom of my pots when I cook because the heat will never reach the water at the top? I can see a still lake that has slightly colder water at the bottom but we are talking about a vast difference in heat here. Also; if the fluild is being picked up by the filter and dumped back into the pan after serving it's function and the vehicle is constantly moving there has to be fluid movement.
While I have complete faith in testing and engineering I am a firm believer in common sense and I strongly believe it takes BOTH to arrive at a proper outcome.