hi, i wanted to know what is meant by -AN size?

is it measured in milimeters or inches?

i just bought a pt6266 turbo and from reading i have learned that, i need a -4 AN line for oil feed and -10AN for return, i have not found an answer anywhere on google, can you guys plz help.

 

Nevermind, use the link below.

 

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

 

ok thanks..

 

another thing i wanted to know, should the inside diameter of the pipe be the same as the outside?

for example the -4AN pipe i measure is 6mm from outside but smaller from the inside..

and theres another problem, the turbo return line doesnt have oil returning from it, when i crank the engine?

is it because of the smaller diameter of the feedline or is it something else?

 

How long are you cranking the engine? It takes a few seconds at least to build up some pressure in the lines....it wont start flowing instantly.

 

http://autoperformanceengineering.co...ead_Sizes.html

The feed is a high pressure feed and the return is just a return.
You will need to crank the engine for a few seconds to get the pressure to build and flow to the turbo. Might want to unplug the injectors and spark plugs and crank the engine.

 

They are measured by the inside diameter (any pipe you measure will be smaller on the inside than the outside) 4an = 1/4" inside diameter if I recall.

Is the turbo ball bearing? If so you may want to look into a oil restrictor.

Also turn the key on for like 5 seconds but don't start the car, then back off then back on for like 5 seconds and then start the car. Let it run at idle for a few and see if the oil starts to drain out the return of the turbo.

Also where are you pulling oil feed line from on the engine?

 

i'll answer all of the question in this post..

1. i cranked the engine for more than a minute, only very small drops come from the return line...

2. the inside diameter of feed line is 3.30mm instead of 6mm which is 1/4''.

3. the turbo is ball bearing with a restrictor already fitted from the manufacturer.

4. the oil is being fed from the head,alot of pt6266 owners feed from head without problem.

what could be the cause that there is no oil from return line?

and should the oil be gushing from the return line when i crank the engine or just little?

 

You also may have some air trapped in there, you may want to crank it for a bit.
The oil 'won't be gushing, just cranking the starter isn't enough to get the pressure really high. Once the engine starts it will flow much more.

 

if i remember right: the number on the fitting represents #/16". so:
a -4 line is 4/16" = 1/4".
a -8 = 8/16" = 1/2"

yeah, the BB turbos use less oil. plus, as mentioned above, it takes time to build up oil pressure (i don't think cranking the engine over even shows on my gauge). if you are getting anything out of the return line, i'd imagine that is a good sign.

 

double post

 

i cranked the engine for a minute, nothing.

then i started it for a few minutes,still nothing.

 

yes a 1/4'' line is 6 millimeters, thats what my line is if i measure from outside, but when i measure the inside diameter, its 3.3 millimeters.

should the inside be 1/4'' or just the outside?

 

Yes, the -an number refers to the outer diameter.