size of transmission cooler ???

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roylerumble

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I have a 408 stroker, 727 with a 3500 stall tq, champion aluminum rad. Blew a pin hole in the high pressure line, so I figured I might as well bend some new ones and add a trans cooler. That tq is likely making a lot of heat. Should I run the high pressure into the rad, the return to the cooler inlet, then the cooler outlet back to the trans, or plug the rad up and run the cooler stand alone? What BTU rating should I run if doing either?
 
I have two Dodge trucks with the factory trans coolers installed. They both go to the radiator first, then to external cooler, then back to the trans. The trans cooler on the Ram Charger I had was roughly 11"x 11" & single pass. I don't know the BTUs, but I think any decent size cooler is a big help. My V10 Ram is a bit larger & has it mounted off to the side of the radiator for better cooling, as it has the room to do so. As long as you mount it where it gets good air flow, maybe even a small electric fan mounted to it, you should be good to go.
 
I use this big bastage... https://www.amazon.com/dp/B085MCHZSP?tag=fabo03-20


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The avatar has a 408/727 combo like yours but with an 8" torque converter that stalls at 5000 rpm. I have a Champion Cooling Systems radiator but I do not run the trans fluid through the rad. Instead, it runs straight to a Derale cooler/fan assembly that I have wired with a manual fan switch.

I have a trans temp sender mounted in the trans out line to the cooler. I drive this car on the street as well as at the track. Trans temps (without the fan turned on) on the street are in the 170-ish range unless I stand on it. Then they might go up to 185-190 and I flip the fan on which will pull it back to 160 or so where I turn it off. At the track, I see 185-190 at the end of the 1/4 mile (11.0x good air to 11.20 on a 95 degree day), turn fan on, back to 160 by the time I'm back to my pit.

You can see the cooler here when I was putting the car together.

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I’ve got a Tru Cool LPD4711 8 x11 mounted to the lower driver’s side in front of the radiator with 3/8 inverted flair fittings.
 
Make sure that what ever size you use, get a plate style cooler. I have mine plumbed through the radiator then the cooler.

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Make sure that what ever size you use, get a plate style cooler. I have mine plumbed through the radiator then the cooler.

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I agree - you just can't beat the plate style coolers.

I can't tell by the photo, but how'd you attach the hardline to the hose barb? Looks like there's some type of AN adapter, but I can't tell how that adapter attaches to the barb.
 
I had AN fittings tig welded on, #6. Have a combo of 3/8" hardlines and steel braided AN #6 lines. This is on my RR, but alike to an A Body. Have no results on how well mine works. Hemi 727 auto. Trans is a street/strip Coan. Just had rotater cuff surgery, so it's going to be awhile!

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Lots of good advice above. My only comment is to err on the side of too much than not enough. I've always been told (by transmission guys/shops) to run the line through the cooler first then through the radiator. Just like engine oil, trans fluid needs to be at operating temperature and routing through the radiator gets it to that operating temperature after having excess heat taken out by the run first through the cooler.
 
Lots of good advice above. My only comment is to err on the side of too much than not enough. I've always been told (by transmission guys/shops) to run the line through the cooler first then through the radiator. Just like engine oil, trans fluid needs to be at operating temperature and routing through the radiator gets it to that operating temperature after having excess heat taken out by the run first through the cooler.
You are correct - especially on a daily driver in cold weather. The rad acts as a trans warmer to help with fuel economy. And in some of today's vehicles, those with separate trans coolers may be bypassed in cold weather also for fuel economy/co2.
 
I’ve got a Tru Cool LPD4711 8 x11 mounted to the lower driver’s side in front of the radiator with 3/8 inverted flair fittings.
Tru Cool are the most effective coolers made. They are like a radiator, exposing the most amount of oil to air flow.
Something that a tube and fin style cooler just don't do. Quality tube and fin coolers will have what they call a "turbulator) in each of the tubes. The object behind this is to tumble the oil as it pass through each tube and uses a "skin effect" to cool the oil. Cheap tube and fin coolers will have a turbulator in only the two tubes you attach your hoses to. That being said, true cool is the better style of cooling. And yes, you can get them with threaded connections, just get one of their engine coolers. Same cooler as the transmission cooler, just has thread connections.
 
I use a B&M 70268 SuperCooler as a stand alone not going through the radiator and it works good on my big block with a 727, 3200 stall and street driven.
 
If you are mounting a cooler to cool your trans temp, WHY would you route you lines through a radiator to heat the trans fluid up? (195° thermostat?) Where I am, I certainly don't need a trans warmer!
Use a quality plate style, as a stand alone.
(Mine is mounted inside the fan shroud, so the engine fan pulls air through it.)
 

If you are mounting a cooler to cool your trans temp, WHY would you route you lines through a radiator to heat the trans fluid up? (195° thermostat?) Where I am, I certainly don't need a trans warmer!
Use a quality plate style, as a stand alone.
(Mine is mounted inside the fan shroud, so the engine fan pulls air through it.)
My WAG is that the coolant exiting the radiator is far cooler than the water entering (190) and water is a very efficient heat sink. That gives the trany fluid a head start before entering the air to fluid cooler .
 
Good choice. That cooler is a repackaged Tru Cool cooler. The size of thread on the engine coolers is 1/2" NPT I believe.
 
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