Oil Feed Restrictor HOW TO:

[JSM]

I had an issue when I first got my truck running. I had run -4AN lines to feed the turbos and nice straight -10 drains to each side of the pan. It wasn't enough though as I had oil come out the backside of the brand new turbo on the pass side.

After some research I found this to be a common problem. Some places sell special plates, some people have used NOS jets, but one person suggested tapping the -4AN with a 10-32 thread and using a set screw.

That is exactly what I did, tapped the fitting part way (that way it can't move down into the turbo), drilled a hole in the center the size I wanted to try first, dab of loctite and in it went.

Best thing is I can change it out for smaller ones later if I find these are still too big, or want to try no restrictor later, etc.

 

[sytyguy]

Re: Oil Feed Restrictor HOW TO:

Jeff...did you notice any difference in oil pressure (via gauge) w/o the restrictor? My truck used to hold a steady 65 psi when warm, but when I went to the RPM 60-1 kit and made my own feed line (3/16" steel tubing from oil filter adapter to top of turbo), I noticed that the pressure hovers around 40-45 when warm now. Cold psi is still about the same, but with the new setup, it comes down an extra 20 psi when warm. I know that the engine/oil pump is okay, and at first, I had a hard time believing that the oil feed line was responsible, but now I'm thinking it might be.

No problem with turbo (holds oil fine), just weird psi readings.....

 

[4C FED]

Re: Oil Feed Restrictor HOW TO:

Yeah, I bought one of these to restrict the flow:
http://cgi.ebay.com/ebaymotors/Function7-Garrett-T3-T4-4AN-Turbo-Oil-Inlet-Regulator_W0QQcmdZViewItemQQcategoryZ33742QQihZ017QQitemZ270208233337QQrdZ1QQsspagenameZWDVW

 

[JSM]

Re: Oil Feed Restrictor HOW TO:

I have not had the truck running long enough to compare or have enough before/after data.

So far the oil problem though is fixed so it must be working. Motor is basically new so I had great oil pressure anyways.

 

[Z SKI]

Re: Oil Feed Restrictor HOW TO:

does this needed to be done with non BB turbos??

 

[JSM]

Re: Oil Feed Restrictor HOW TO:

does this needed to be done with non BB turbos??

Sometimes, depends on engine pressure.

A restrictor will never replace a good drain though, so make sure the drain is good to begin with before doing this mod.

 

[It's just a six]

Re: Oil Feed Restrictor HOW TO:

Mike @ RPM said the BB Turbonetics turbos do not need a restrictor.
It is the other Co.'s turbos that have this oil consumption problem.

 

[sharkbait]

Re: Oil Feed Restrictor HOW TO:

i kinda don't understand.

i thought that if the oil drains back into the oil pan too fast, you can starve the shaft of oil (because its leaving to fast)

if you restrict the drain too much, your oil thats on the shaft will "burn" or crystallize because of the heat/friction?

can anyone explain why im wrong? im sending my stock turbo to jwaller and he will be doing an upgrade for me this month. im going to use a new -4 feed with AN fittings with the stock hard drain (cleaned up and painted)

sorry, i just want to do the right thing...........but i also want to understand why some things work and not others.


thanks
domenick

 

[ghettosled]

Re: Oil Feed Restrictor HOW TO:

you could also just buy a fitting like this with a .035" restrictor hole

or this and drill your own hole

 

[JSM]

Re: Oil Feed Restrictor HOW TO:

I wanted to be able to change out the size of the restrictor allowing me to start larger than most off the shelf restrictors. But your right there are off the shelf solutions also.

Best to consult whoever you bought turbo from on if to use a restrictor or not. This topic can be debated. I did a lot of searching on turbomustangs.com forums about the topic to finally come to my decision on what to do.

 

[Don W.]

Re: Oil Feed Restrictor HOW TO:

i thought that if the oil drains back into the oil pan too fast, you can starve the shaft of oil (because its leaving to fast)

if you restrict the drain too much, your oil thats on the shaft will "burn" or crystallize because of the heat/friction?

You do not want to restrict the drain in any way. Once the pressurized oil enters the turbo it is routed to the bearings. Once it goes through the bearings it has done its job and needs to drain back to the pan unrestricted. Think of the other bearings in the engine, Once the oil lubes the bearing it's done and just returns to the pan. (Maybe not a very good analogy but I think you'll get the idea.)

 

[ghettosled]

Re: Oil Feed Restrictor HOW TO:

you also need to remember that when the oil exits the turbo it is in a foamy state and will not just flow back into the pan like a stream of oil. That coupled with a little bit of crankcase pressure it needs all the help it can get returning to the pan. On alot of the low mount turbo applications you have to build small catch cans to allow to oil to settle then pump it back to the motor.