Author Topic: 4L80e cooler and lines  (Read 2115 times)

Offline nighthawker5

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4L80e cooler and lines
« on: November 14, 2017, 01:40:58 PM »
Hi everyone,

Im getting close on my 6.0L and 4L80e swap in my 86 K20 and had a few questions on the cooling lines.  I am planning on using an external cooler and will not go through the radiator at all.  I'd still like to use hard lines but I can see the fitting in the transmission is a little different than other trans I have seen.  I can only find AN adapters online and wanted to know where I can find hardline with the right fitting. 

Also I was planning on using a B&M Supercooler PN 70265 (11x4.5x2.5) mounted to the framerail and was wondering if this would be enough.  I would tow occasionally and carry firewood in the bed.  I planned to fab up some sheet metal brackets to protect it a little from debris. 

Thanks in advance

Offline bd

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Re: 4L80e cooler and lines
« Reply #1 on: November 14, 2017, 04:22:24 PM »
If you're eliminating the factory wet cooler, I recommend a larger stacked plate cooler than the 70265, having greater heat rejection capacity, such as the B&M 70272 (as a minimum), or the 70274 since bigger is better for improved transmission life; then plumb using seamless 1/2" aluminum tubing, the appropriate 1/4" National Pipe Straight Mechanical thread (NPSM) transmission fittings and 1/2" tube to -8 AN fittings.  Read the promo from B&M Transmission regarding their recommendations on cooler size and mounting considerations. 

Since you're fabricating new lines, consider installing a gauge manifold in the hard line for easier installation of a transmission fluid temperature gauge sending unit.  Hard line can be securely anchored to the frame using T-clamps.  If you need to run the hard line through the frame rail or radiator support employ bulkhead fittings with AN fittings to match - it provides a solid base for transitioning to flexible AN hose between the frame and body or radiator support.  There are nearly unlimited configurations that can be tailored to fit your particular needs.

Edit:

Use flexible hose with adequate slack between the transmission and frame to allow for transmission movement without straining the hose, lines or cooler.  In addition, allow for adequate airflow across the cooler or substitute forced air cooling such as a fan.
« Last Edit: November 14, 2017, 07:04:28 PM by bd »
Rich
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In other words... if people learn by making mistakes, by now I should know just about everything!!!
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Offline nighthawker5

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Re: 4L80e cooler and lines
« Reply #2 on: November 15, 2017, 06:18:27 PM »
Very good info.  Thank you so much