Just wondering what size lines you guys are using for your oil drain lines. I assume nothing is too big, just overkill, but what size is too small? My oil feed line to my SR20 turbo is -4 and I am using a 1/8" I think pop rivet for my restrictor, so what size I.D. drain hose should I be using?

 

5/8" should be sufficient.

 

Agree, I'd run -10 or -12

 

I'm using a -4 feed line with no restrictor and a -10 drain line. Now I less than 10 miles on my new set up so I'll let you know how it turns out, but with the -4 feel line and no restrictor the turbo see a max of 30psi of oil.

 

Is this at idle?


With no restrictor and a -4an line I don't see how it wouldn't see over +90psi of oil pressure when you near 7000RPM.

I personally have to run a .040" restrictor with my -4an line; even a .065" orifice is too large.

 

-4 feed. 5/8 drain, no restrictor.

 

T25G? that a Ball Bearing turbo? Those tend to have a built in .035" restrictor.

 

-3AN feed, -10AN drain hose

 

Journal bearing off an SR20.

 

I'm using some of that water pump tubing that runs to the heater core (5/8" I think). Here's some oil flow using a -3 feed line (no restrictor) t3 center and a shimmed oil pump at ~1000 rpm idle. I've run about 500 miles since the install and haven't had any issues w/o a restrictor. YMMV

 

On a T25 turbo a -8, -10, or 5/8" is sufficient.
Stephanie

 

I've been looking for this video forever.

Anyway, -8 = 3/8", right?

 

-8 ~ 1/2"

 

just a minute....

 

Nominally, the AN sizes go in increments of 1/16". So -8AN should, in theory, be 1/2" ID.

That said, these is tremendous variance in actual sizing from one hose to the next, which is one reason why, when assembling AN lines, you have to be sure that the hose ends you have selected are rated as being compatible with the particular hose you are using. (variances in OD, even for a common ID, are another)

As an example, Earl's Auto-Flex has an actual ID of .438, whereas Earl's SuperStock had an ID of .5, and Earl's Speed-Flex has an ID of .563.


That said, +1 on -10. (that's looks weird to write)

 

-4 supply no restrictor, -12 drain . that's on a big 16g. went for the way overkill setup. no issues and it looks bitchen'.

 

Hot idle is right around 7psi if I recall correctly I'll take an other look at it. I'm using a GM brake banjo bolt (found in the "help" section of most parts stores), with a banjo to -4 adapter, and -4 into the turbo and oil psi gauge.

 

So my feed line is a -4 and I am running a 1/8" pop rivet for restrictor. My drain line is 3/8". My question is, will this drain line in time be insufficient and cause my seals in the turbo to blow and leak oil?

 

So if 3/8 -8, am I looking at this chart wrong?


http://www.anplumbing.com/thread_npt.html

NPT 3/8 closest AN Ftg. Size is 8?

 

http://en.wikipedia.org/wiki/AN_thread

The AN size is based on OD, apparently.