An education on transmission coolers... - Page 3 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend
User Name
Password
lost password?   |   register now

Closed Thread
 
LinkBack Thread Tools
  #31 (permalink)  
Old 10-01-2011, 07:32 AM
Registered User
 
Last wiki edit: How to make a custom dashboard
Last journal entry: Interior Tin
Last photo:
Join Date: May 2011
Location: Florida
Posts: 54
Wiki Edits: 4

Thanks: 0
Thanked 0 Times in 0 Posts
I can't comment on the original thread as I didn't see the setup or how it was instrumented or conducted, but I can talk about my personal experience. I have lived in central Florida for over 25 years and have fought cooling problems with almost every hot rod I have owned. I put an engine and trans sump temp gage in just about everything so I have some idea of how these two things relate. In general, the trans runs about 5-25 degrees above the engine water temp which sort of makes sense as the trans fluid going through a typical radiator cooler can not be any cooler than the water temp after it reaches steady state. Cooling the engine typically cools the trans, so a lower thermostat usually keeps it cooler. I have had GM, import and Mopars and universally saw this result. I put a couple of fin and tube coolers on, and to be honest never saw much of a change except when under heavy loads for long periods of time it does help some. This seems to be the subject of most of this thread. What I found to be the best thing is a little bit different and I found by accident.
When rebuilding my truck, I wanted to be able to keep the engine cooler that 210 based on the setup I was running, and the stock 1 core aluminum radiator would not do it, no matter how big the fan or how low the thermostat. I found a 3 core Griffin unit that fit, but it was for a 4 speed car and didn't have a cooler on it so I put on a dual puller fan and put a Flex-a-Lite fin and tube cooler on the front of the radiator and AC condenser. It has -6 inlet and outlet, and I ran braided lines (it is a 7.5" X 15" unit). My tranny now typically runs at about 180, and only if I am really pushing on it does it ever approach 200. The highest I have ever seen is 205 in Orlando traffic on an August afternoon.
Now I don't have the data to show what it would be running with the motor at 190 and an in-radiator cooler, so my data is just for my setup and other setups may have differing results. What I can say is that in this application, the fin and tube cooler with no other help has kept a 4000lb truck with a 360 Magnum and way too much cam in front of a 3000 stall converter on a A518 tranny (727 w/OD) running fine in Florida traffic.
Again, this is my specific experience, but what I learned is the cooler does work, and decoupling from the radiator actually helps even more.

    Advertisement
Quick reply to this message
Sponsored Links
Advertisement
 
  #32 (permalink)  
Old 10-01-2011, 10:15 AM
willys36@aol.com's Avatar
Hotrodders.com Moderator
 
Last wiki edit: How to rebuild a Rochester Quadrajet 4MV carbureto...
Last journal entry: How to change auto shift timing on 200R4
Last photo:
Join Date: May 2002
Location: Bakersfield
Posts: 8,384
Wiki Edits: 21

Thanks: 1
Thanked 4 Times in 4 Posts
Everything you say makes total sense mmopar. Factory runs tranny fluid thru the radiator to keep tranny in a desired operating range. It wants to be hot so condensate doesn't collect and corrode the thing to death. It doesn't want to be so hot it burns fluid and destroys rubber. Turns out that engine coolant temp is the perfect range. Add an external cooler if your engine runs too hot for extended periods but you have to follow the rules and make sure you have adequate air flow over the fins/plates/ whatever type it is. Don't worry about friction pressure losses/heat gains in any aftermarket unit. Flow rate in a tranny isn't that high. The volume is enough to circulate the torque converter which does generate heat and needs convective cooling. All the fluid going to the valve body is drips - it depends on pressure signals, not flow rates to operate.

Then there's my favorite tranny, the old GM Hydramatic cast iron 4-speed with its weird fluid coupling, not a torque converter. They simulated a torque converter with a quick 1st/2nd gear shift in that box. Amazing thing about those trannys which were developed for military tanks in WWII is even running the inefficient fluid coupling, they had no provision for cooling and they are legendary for their longevity and strength!
Quick reply to this message
  #33 (permalink)  
Old 10-01-2011, 12:40 PM
Registered User
 
Last photo:
Join Date: Apr 2007
Location: Seattle, Wa
Posts: 6,705
Wiki Edits: 0

Thanks: 3
Thanked 406 Times in 351 Posts
Quote:
Originally Posted by 10scnd70
Does any of it have to do with transmission coolers? If not, none of it is applicable. Get back to us after you install some temp guages on a cooler.

Frank
Your problem, more specifically, the design of the cooler installation is causing the problem. You haven't discovered new physics just applied a troublesome solution.

I'll give you that a stacked plate cooler is more efficient at heat transfer than a finned tube. The reason is the liquid flowing through the cooler is passed through many very thin spaces that have a lot of fin area against the volume of fluid. The finned tube does not have such an engineering advantage. This does not negate the science, the stacked plate is simply a better engineered solution. That said, the finned tube is used in many installations and is sufficiently effective when properly engineered.

"Properly Engineered" is an issue when you buy coolers. Very little data is made available to the consumer on heat transfer rates in terms of BTUs per some measure of time which is how it gets engineered in the first place. But the sellers of these things usually just say something about vehicle weight and maybe engine size, which is a pretty broad brush approach at making it simple.

I suspect that the installation you did of two cooler in series caused an engineering problem that was mistook as a science problem. What I expect is happening is that the transmission pump has excess capacity, well in fact I know that it does, that's what the relief valve is put there to place an upper limit on before the pump generates enough pressure to damage parts. There is a sizable difference between the pump's normal operation against a normal oil leakage load which then defines the typical system pressure and will also determine the oil temp rise caused by the pressure increase of the pump. In essence the transmission looks like a resistance the pump is pushing fluid against. The installation of a cooler adds, if nothing else, distance to the plumbing, this alone increases the resistance the pump is working against. This raises the temperature of the working fluid, in this case tranny oil. If the cooler has one of those twisted dividers in the tube which is intended to increase the heat transfer rate which it does, the resistance against the pump goes up again. To some extent this always like a dog chasing it tail, everything that improves performance in one place costs something somewhere else.

Adding a second cooler in series also added more resistance against the pump which causes the fluid temp to rise again. In total the head resistance against the pump caused the fluid temp to go up higher than the cooling (heat transfer rate) ability of the tube and fin to transfer that heat to the atmosphere. So you read it's rate of transfer failure as hotter oil coming out. This doesn't change the basic physics, its a design problem.

If using the tube and fin cooler is the only choice than a better design solution is to divide and conquer. That is to plumbed the coolers in parallel instead of series. To the pump this looks like the area of the tube was increased instead of decreased so the pressure rise and attached temperature rise does not occur at least not to the extent of it seeing the resistance of coolers in series.

Guys with rods built on 1920 through early 1950 chassis see a lot more cooling problems which is the result of not enough radiator area and poor airflow through the radiator and engine compartment. These vehicles had cooling problems when new when using much smaller engines both physically and power wise, manual transmission, and the only accessory was small generator. Now we're trying to cool a 300 or more horsepower engine with a 100 amp alternator, power steering pump, and air-conditioning compressor and all the attentive plumbing, with headers on the same radiator area and all this crammed into the original space that used to flow air around the engine.

To pull this off you've got to get tricky. You need to add coolers for the engine and tranny oil. Chances are there will be no space available with any air flow so you need to use heavy frame members as heat sinks and or add air ducts where they are out of sight. For example, rectangular tube with no fins can be bolted against the frame rails, making tight contact for heat transfer can be used to pull heat out of the oil and sink it into the mass of the frame if you cannot find space for a cooler that's in the breeze.

Root Cause Analysis, you have to study problems which includes the theory and science to arrive at adequate engineering solutions. The books aren't wrong, but to any scientific definition there are many engineering solutions, some are better than others. All are trades between cost and performance, like a tube and fin cooler is less expensive than plate types, but it is also less effective. somewhere in all of this the best solution based on Design to/for Cost and Life Cycle Cost requirements. Everything at the store went through these analysis to arrive at a technical solution that costs what the market will bear. That answer for the same question will be different for NASA than for the average guy. But the basic question is the same for both which is "Speed Costs Money, How Fast Can You Afford to Go". Interestingly enough, when I was a kid growing up outside San Diego, our local speed shop had these words on a banner behind the counter.

As far as me writing mostly about engines versus transmissions, it's because I love engines best but like Tom Sellick's response to the dying Alan Rickman in Quigley Down Under regarding his proficiency with a pistol, "I said I never had much use for one. Never said I didn't know how to use it." I'm that way about transmissions, rear ends, brakes, body work though I love to shoot paint as long as someone else is cleaning up

Bogie
Quick reply to this message
  #34 (permalink)  
Old 10-01-2011, 12:42 PM
killerformula's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Carburetor
Last journal entry: Clean up
Last photo:
Join Date: Oct 2003
Location: Northeast
Age: 34
Posts: 3,485
Wiki Edits: 3

Thanks: 13
Thanked 27 Times in 18 Posts
I agree with the above, there's definietely something amiss with the logic here. Pressure does not create heat in fluid which can't be compressed. I think you're thinking of the ideal gas law pV=nRt. Pressure and volume relate to a gas constant, number of particles and temperature. More pressure more temperature. Not true with a fluid. Too much of that "library learning" I guess.

After reading the title and the first couple lines of the first post I knew this thread would be trouble. Amazing how somebody isn't received well when trying to lecture people with lifetimes of experience based on their experience with one car.


K
Quick reply to this message
  #35 (permalink)  
Old 10-01-2011, 01:30 PM
user151's Avatar
Registered User
 
Last photo:
Join Date: Dec 2008
Location: new england
Posts: 194
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Quote:
Originally Posted by killerformula
After reading the title and the first couple lines of the first post I knew this thread would be trouble. Amazing how somebody isn't received well when trying to lecture people with lifetimes of experience based on their experience with one car.
K
While most everyone seems to disagree with the OP (as I do), Frank may have done a favor to those considering an add-on or stand-alone air cooler for transmissions: A lot of good info has come out.
Bogie mentioned two ideas I have not seen before and will consider in future builds.
Quick reply to this message
  #36 (permalink)  
Old 10-01-2011, 04:05 PM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,333
Wiki Edits: 0

Thanks: 2
Thanked 27 Times in 27 Posts
The OP is right about the stacked plate versus tube and fin coolers. The heat transfer rates for the stacked plate type are much greater than the tube-fin.
Quick reply to this message
  #37 (permalink)  
Old 10-01-2011, 04:39 PM
1badLemans's Avatar
Registered User
 
Last photo:
Join Date: Nov 2010
Location: colorado
Age: 32
Posts: 152
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Oh man this is a great debate lol. I just wanted to chime in here as I have a project where the engine pulleys are way too close to my radiator and i'm running an electric pusher fan on the front of the car(bumper side) which doesn't really leave me room to mount a stacked plate type cooler. So I was thinking of just buying a finned tube type cooler and mounting it somewhere on the frame horn or rail. I have used the stacked plate type on 3 cars with absolutely no problem at all but never a finned tube type so this conversation started to worry me. But then I read thru these posts and noticed that first off I could care less about the temp before and after the cooler, I just care about what the temp is at the pan. Wouldn't this be the best place to take readings??? Also where was the tube cooler mounted for this test? Same spot as the stacked type?
Quick reply to this message
  #38 (permalink)  
Old 10-02-2011, 01:19 PM
Registered User
 
Last photo:
Join Date: Jul 2004
Location: At Speed
Age: 51
Posts: 1,333
Wiki Edits: 0

Thanks: 2
Thanked 27 Times in 27 Posts
Now I'm confused.

Hayden makes both plate and tube coolers and says the plate type are 33% more efficient.
http://www.haydenauto.com/Featured%2...s/Content.aspx

But, GM uses a tube type for the ZR1 engine oil cooler and Allison uses a tube type for their trans cooler.
Quick reply to this message
  #39 (permalink)  
Old 10-02-2011, 01:37 PM
user151's Avatar
Registered User
 
Last photo:
Join Date: Dec 2008
Location: new england
Posts: 194
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Plate type is more efficient - but all that means is that if you are going to use a tube type it has to be larger to get the equivalent cooling.
Quick reply to this message
  #40 (permalink)  
Old 10-02-2011, 02:12 PM
Registered User
 
Last photo:
Join Date: Nov 2006
Location: Woodstock
Posts: 850
Wiki Edits: 0

Thanks: 2
Thanked 68 Times in 62 Posts
Quote:
Originally Posted by lmsport
Now I'm confused.

Hayden makes both plate and tube coolers and says the plate type are 33% more efficient.
http://www.haydenauto.com/Featured%2...s/Content.aspx

But, GM uses a tube type for the ZR1 engine oil cooler and Allison uses a tube type for their trans cooler.
For the ZR1 and Allison comparision, maximum cooling probably isnt 1 of the primary motivators, cost/packaging perhaps? OEM's dont use the "best" components available.

Which ZR1 are you referring to? ZR-1 as in LT5 or ZR1 as in LS9?

peace
Hog
Quick reply to this message
  #41 (permalink)  
Old 10-02-2011, 04:41 PM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,906
Wiki Edits: 0

Thanks: 0
Thanked 73 Times in 61 Posts
I don't think you will find anyone willing to argue the stacked plate versus tube fin cooler debate, everyone knows the pancake style is way more efficient...look at the surface area duh!

But saying fluid is heating up while going through a tube is simply incorrect and unless you were using calibrated RTD with a dual pickup input to read them simultaneously...well lets just say plain gauges are notoriously inaccurate especially when you are trying to compare two different gauges.

What confuses me more is this "I'm gonna teach you" attitude, good way to make friends! BTW I take care of process equipment where both types of coolers are used and one thing you have not considered is that a fin and tube style is meant to be used at high air speeds where they present low restriction to airflow compared to a pancake style which works more efficiently at low or more static airspeeds.

Do you think that might be why they sell the tube and fin style coolers for those people that want to tow a trailer on the highway where the difference between the two types of coolers are minimal. Not to mention the lower cost when to the average boat/camp trailer towing public it works just fine for its intended purpose.

You might want to do some research into why each style of cooler exists in industry and not make blanket statements about a piece of equipment you claim to know so much about. The only cooler that performs equally in both situations is the same style used in the common car radiator which is a hybrid of the two.

Darn close to breaking that golden rule wouldn't you say?
__________________
Outlawed tunes from outlawed pipes
Quick reply to this message
  #42 (permalink)  
Old 10-02-2011, 10:04 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by 4 Jaw Chuck
Darn close to breaking that golden rule wouldn't you say?
For those who ENJOY a good, down in the ditch dust-up, the "golden rule" deal really doesn't work anyway. I mean if you don't care what someone else says back to you, then what?

But back to coolers. I firmly believe using a cooler- either a tube and fin or a stacked plate- can help the longevity of a transmission if it's used in such a way that temps are not fully controlled by the OEM set-up.

Follow the manufacturer's instructions and your own common sense.
Quick reply to this message
  #43 (permalink)  
Old 10-08-2011, 10:47 PM
Registered User
 
Join Date: Oct 2011
Location: Maryland
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Hey Frank

It's kinda funny how you ll write a novel on something as stupid as a trans cooler, but you can t respond to people who you took thousands of dollars from to build "the worlds best" tranny. BTW franks not as tough in person as he is when hiding behind a computer, plus he s too feminine to install a cooler. Go to the camaro z28 website to see what kind of business man he really is.
Quick reply to this message
  #44 (permalink)  
Old 10-09-2011, 12:32 AM
Member
 
Last wiki edit: Window removal and installation Last photo:
Join Date: Dec 2003
Location: SC
Age: 51
Posts: 263
Wiki Edits: 11

Thanks: 0
Thanked 4 Times in 4 Posts
Interesting. I have to say there's a factor missing from the original "experiment". There had to be a big restriction at the cooler connection or SOMETHING else going on.
Transmission shops routinely use flushers to run fluid through coolers to remove any crud while the transmission is out. The better flushers heat the fluid too. I can testify that just sitting on the rack in the shop you can tell which direction the fluid is flowing just by grabbing the lines. Even with no air flow at all through the coolers the return line from Hayden type coolers will be notably cooler to the touch than the feed line.
Just saying with the GN at the beginning might have had another problem that accidentally got fixed at the same time the cooler was swapped or there was something failry unique going on. Just my opinion. It's well known that for oil, ATF, and intercooling that plate style coolers are indeed more efficient (and heavier and pricier) but not THAT much more efficient than tube and fins. Plates are only a little less restrictive overall too. This stuff is pretty important to turbocharging guys where "pressure drop" through an intercooler and it's heat shedding ability are important to their tuning equations.
I will take direct issue with this statement-"A converter does generate more heat while sitting still and stalling than it does going down the road" The "and" has got me. Unless your car is idling at 1800-2000 RPM at idle it is NOT stalling while sitting still. It's not in stall at idle, not applying power, just swishing fluid around. Stopped and idling in gear actually the pump is putting more heat into the fluid than the converter. Which I admit is making a little heat, but so are other parts of the transmission.
I'm not counting powering up against your line lock while the tree counts down. THAT generates a buttload of converter heat. I take it we are talking normal street driving.
Quick reply to this message
  #45 (permalink)  
Old 10-09-2011, 01:32 AM
35terraplane's Avatar
Registered User
 
Last photo:
Join Date: Sep 2010
Location: MN, ON THE DARK SIDE OF THE MOON
Age: 70
Posts: 1,310
Wiki Edits: 0

Thanks: 2
Thanked 50 Times in 44 Posts
Coolers

Didn't anyone catch the op's post #22 He owns a shop, so that might have been a round about way to jump classifieds. 2nd he was using a race engine which might throw a curve into the reason why his was getting hot.

I have used the fin and tube for years on a streetrod, always kept it out of in front of radiator, so i didn't have the hot air from that blowing through. I never had a problem, but after this I'm going down and get some good temp gauges, how many do I need again.

Bob
Quick reply to this message
Closed Thread

Recent Transmission - Rearend posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
transmission coolers badbuick81 Transmission - Rearend 7 10-30-2011 04:42 PM
transmission coolers biohazard_81c10 Transmission - Rearend 7 09-30-2011 09:23 PM
Transmission coolers yragat Transmission - Rearend 8 01-28-2008 01:18 PM
transmission coolers, what kind and size to get? fumplet Transmission - Rearend 6 09-10-2006 10:47 PM
hei education nettio Electrical 3 08-26-2005 11:53 PM


All times are GMT -6. The time now is 05:14 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.