What size AN lines?

[JeepSJ]

I searched and found lots of discussion about the oil cooler lines, but found nothing about what size to use. I'm debating between -10 and -12. The block is a '97 and it has the big oil spray holes.

While we are at it...-6 or -8 for the trans cooler?


Thanks!

Mark

[DmaxMaverick]

AN fittings (Mil Spec flare) are gauged by the tubing size. The -# is the outside diameter of the tubing in 1/16" increments. -10 = 10/16", or 5/8". A -12 would be a 3/4" line. Best to just measure the OD of the tubing you are questioning. Some year models crossed over the size and applications (moreso the late 96's), so measure to be sure. A -10, or -12 would be more in line with the nut size, not the tubing. Be careful when judging tubing sizes. Sometimes, the nut size is not standard, especially in the automotive world.

Although the tranny lines are inverse flares, the sizing is the same.

[JeepSJ]

Thanks for that.

So, -10 or -12 for oil lines? I am building a set of oil cooler and trans cooler lines for the Waggy. I will be using all AN fittings and lines. I have no stock lines to look at or measure. Let me ask another way...should I run 3/4" or 5/8" lines for oil cooler? Should I run 3/8" or 1/2" for trans cooler? Those of you who have built your own lines, what size did you go with?

[DmaxMaverick]

OEM (6.2/6.5/6.5 w/spray) oil cooler lines are 3/8" (-6) or 1/2" (-8). Tranny lines are -4 or -5, and don't need much more for the low flow. If you are looking at overkill, do what you like.

[JeepSJ]

Thanks!

After a little more research, looks like the companies that produce replacement oil lines are using 5/8" lines, so I'll probably stick with the AN10 for that. As for the trans lines, looks like the hard lines are 5/16. Since -5 stuff seems to be hard to find, I'll do those in -6.

Look for updated pics in my album soon!

[Robyn]

Quicky check
As long as the ID of the line you are using is no smaller than the ID of the fitting on the engine and tranny your fine. The will only flow as fast as the hole it comes out of. (within reason) What you are thinking about will work sweet.
The cooler tubes are the bottleneck anyway although they flow good and easy with little back pressure

[DmaxMaverick]

Tubing size is outside diameter, hose size is inside diameter. When having both hose and tubing of the same size, the restriction is in the tubing, not the hose. The tubing flow cross section will be less, by the amount of the tubing wall thickness. While I'm a big fan of overkill, hoses of too large a size is a waste and takes up more space, and increases interference/chafing risk. Also, larger hoses need a larger bend radius, which can be significant.

Nothing wrong with using -6 tubing for the tranny lines. The added surface area will be beneficial to cooling. Problem is the size in tight spaces. If you need -5, you can get it. It's less common, but available. Also, if you are using steel line, do not try to double-flare the tubing. That's only for aluminum lines unless you have a special flare tool, usually unique to the aircraft world.

[mhagie]

-6 tran and -10 oil are perfect, where you need to watch is the fittings, not all fittings come close to line size.
On my 02 max I have the Amsoil BK-17 bypass kit and it uses -8 hose and fittings.
The -8 is considered adequate by amsoil and many users but I'm kind of anal on oil supply to that unit so I have converted mine to -10 and drilled out the fittings to as close to hose size as possible.
-10 is considered 5/8 but if you mic it it is less than that, I consider it barely over 1/2, 9/16 max.
Don't make any difference what size hose you use the fittings will determine the flow if they are less than the hose size and all i have seen are smaller.
Merle

[DmaxMaverick]

The insert part of the hose fitting will have a similar inside diameter as the same size tubing. It may be a little larger, but not much at all, depending on the fitting brand and rating.