Going to go -6 lines from the trans to the radiator and external cooler. Need to know what size the fittings are on the radiator for the cooler lines. To be honest, I would like to keep the hard lines and find fittings to connect -6 to them.

 

5/16" inverted flare

 

http://www.summitracing.com/dom/part...0027/overview/

That's what I used, I talked about the pain in the *** it was on my build thread. Now that the job is done, I'm happy with it. Most of the displeasure was getting told the wrong fittings and threads for the cooler line fittings in the side of the trans. That and getting the lines off without dropping the trans. Also, be sure to use the same brand fittings and hose. Hot Rod had some transmission lines pop off on the Crusher Camaro because they mis-matched fittings and hose.

 

I take it the an6-3/8npt is the adapter for the radiator. That is the one I am not sure on.

 

No. I still have two left. I ordered everything on that list, and then found out that the transmission fittings were wrong. The radiator is AN-1/2 x 20. The transmission cooler lines are SUM-220027, order one because they come as a pack of two. The cooler is up to you, but I picked up a Derale 13320 and the Summit cooler mounting kit.

 

They are 5/16" inverted flare.

The threads on the nut for that size fitting are ˝"-20.

No idea why they AN fitting makers specify their fittings by the thread size instead of the tubing size and flare type like everybody else in the world. Truly unfortunate. Provides no benefit and just causes massive confusion.

They are 5/16" inverted flare.

At the transmission end, there are also brass pipe-thread adapters that screw into the case, which the 5/16" inverted flare tubing then screws into. You therefore also have the option of removing those altogether and using adapters that go straight from the pipe thread size to AN. They may be 3/8" pipe, I can't recall for that particular transmission, and if so, that would make them rather difficult to adapt to/from, being an extremely unusual size for anything automotive. I'd be more inclined to suspect that they're actually Ľ" pipe like GM transmissions have been since they invented them, which is about 9/16" OD and has around 12 or 13 threads per inch. (and of course is tapered like any other pipe thread) But if they ARE 3/8" NPT, which would be around 11/16" OD and about the same thread pitch as Ľ", you could just go to the hardware store and get a pair of 3/8" - Ľ" bushings, and then adapters would be MUCH easier to find.

Some radiators also have miscellaneous adapters in the cooler, but they ALL go from whatever the radiator mfr decided to make their holes, to 5/16" inverted flare; that being the factory tubing size and fitting and therefore not subject to arbitrary change by replacement parts suppliers.

 

Not 100% sure about the adapters that you mentioned Sofa, but at least on the 4L60 the threads on the case are NPS. I tried to use NPT, but it got about 1/4 of the way threaded in where it wasn't even finger tight and wobbled about, and then got super tight. I didn't feel comfortable using those, so I ordered the Summit transmission line adapters I mentioned earlier.

 

http://m.summitracing.com/parts/sum-220668

So this fitting here is what will screw into the radiator?

 

The nut on the hard line is the 5/16 inverted flare, correct?

 

I'll take some pictures once I get home.

 

The combination of the nut and the flare on the line is that.

It's 5/16" tubing, with a double flare machined onto the end; and the nut to screw it together. The nut is specifically designed for that one single purpose. It happens to have ˝"-20 threads.

Yes that adapter will screw into the radiator. A similar one will screw into the brass piece on the side of the transmission; not the transmission itself. What khulsebus is actually talking about, and the part # he posted for the 3/8" NPT to AN6 adapter like he shows http://www.summitracing.com/parts/sum-220648, would screw into the actual transmission case, replacing the brass piece that's there now. You could either do what he lists, or, get 4 of the one you posted and use them at both ends, leaving the existing brass adapter in the trans. Your call. If I were doing it I'd probably use the same adapters he lists, if for no other reason than to simply minimize the # of junctions.

 

It's a little tight in the tunnel too, besides there being two more connections to leak from. I don't know if I would have had enough room to use the stock adapters and the 45 an fittings. Sofa puts out good information.

 

Yes. Let me know if you want pictures of the lines and what not on the car.

 

all the cars we've been doing at the shop have been 1/2 20 inverted flare 1 was a turbo 350 and the other a 200r4 http://www.summitracing.com/parts/rus-640330

 

Yup; as stated above, for some reason unknown outside of their hallowed halls, the people who make AN fittings describe flare fittings by the threads on the nut, rather than by the tubing size and flare type like the whole rest of the world.

And as also stated above, 5/16" inverted flare fittings happen to have ˝"-20 threads on the nut. That's the size on virtually EVERY GM car, and most others besides.

 

So which -an fitting goes to a 5/16 inverted flare? To run AN lines from the hard lines to cooler and cooler to transmission connector? Maybe it was above and I just didn't see it? I'm probably blind...

 

http://www.summitracing.com/parts/sum-220668 is one. There are plenty of others as well. A search on Summit's site will turn up acoupla pages worth.

 

Ok, my plan is to go from the transmission, into the aux cooler, out of the aux cooler, into the radiator.

This one:
http://www.summitracing.com/parts/ear-991946erl

To go into the radiator. The -an end goes to the hose into the tranmission cooler.

Which fitting will connect to the hardline coming from the transmission (connects to the inverted flare piece I just pulled from the radiator to install the above piece)?

 

Do yourself a favor and get rid of the hard lines. Not having to wrestle with the hard lines when all you want to do is pull the radiator, or get the trans out. Honestly, it's nice to just take the fitting off and be able to coil the line out of the way.

Also, make sure that your flow is going Trans-Radiator-Cooler-Trans. If you go the other way around if your cooler drops the temps below whatever your coolant is sitting at in the radiator, the radiator will just heat it back up. If you go the other way around (like in the case of my car) it comes out of the trans, hits the radiator (coolant is at 195), hits the cooler and drops some more, then goes back into the trans. The return line for a 700 or 4L60 is the top fitting.

 

That's a lot of braided hose to buy though, and the hard lines are still in good shape.

I've always been told to go trans cooler, radiator, transmission, this way the cooler "helps" the radiator cool down your fluid, putting less stress overall on the system. That and you don't want your coolant being "too cold" going back to the transmission.


So you're saying also that the "feed" line from the transmission is the bottom line, then the fluid returns from the top fitting going back to the transmission? It hought it was the other way around?

 

I bought a 20 foot roll, and still have some left over. I wasn't exactly stingy with it either. I guess it's possible to over cool your fluid, I haven't personally had any experience with it. Maybe if someone used an AC condenser or something.

http://www.hotrod.com/feature_storie..._transmission/

 

Good article.