0piston

iTrader: (9)

I was replacing the oil feed line today and noticed that the feed hole that attaches to the 90' fitting is so... very very small.

My question is: If oil is the life blood of the turbo, wouldn't it be more efficient to double the size of that hole with a small drill? Or does doing so have any detrimental effects?

Could be a quick worthwhile mod.

spyfish007

Well this was a conversation in another thread lately. The rx7 oil pressure is so high that it must be reduced rougly 1/2 for the single turbos.

RETed

It's small for a REASON.&nbsp Most people freak out at the notion of using the -3AN or -4AN lines for their turbos.&nbsp The reality is that anything larger would ROB precious oil pressure and supply for the rest of the engine.&nbsp Don't believe me?&nbsp Try it - we "blew up" a perfectly good 13B-REW because -6AN looked about right.&nbsp Sure, the turbo was happy, but this bypassed precious oil to the rotors.&nbsp What was the effect?&nbsp This killed the oil control o-rings - motor start smoking like a **** in about a month.&nbsp Oil pressure off the gauge showed it was about 15psi-20psi low that "normal."

Now, with that in mind, the turbo oil outlet needs to be the BIGGEST you can stuff under there.&nbsp The thing is gravity fed, so the larger the better.

Anyone who has researched turbo CHRA design knows that the oil passages are very small.&nbsp The oil bearings only need a slight film of oil to work efficiently.&nbsp The oil passages are actually designed to "trap" the oil slightly in the CHRA, so thus the small oil inlet line works fine...



-Ted

sub-zero

Quick question? Does any body know the size of the tubing fitting on an FD that feeds the turbos? My turbo kit was missing this adapter piece and I am having a very hard time finding one, i think it is metric but not sure and luck has it the steel braided oil line to the turbo is standard fitting, I think I am in trouble. I guess I can take a tubing cutter and cut off the factory fitting and try a standard one but what if the tubing is just a little different.

Marcel Burkett

Thanks again guys , you yet again SAVED MY *** and my engine ,I was about to install my T66 with a -6AN fitting , But can I still use the -6an line but reduce to a -3AN immediately at the oil inlet?.

AJatx

iTrader: (1)

You can also tap the inside of the NPT end of the fitting going into the CHRA and put a small 60 or 62 holley carb jet.

If you don't evacuate the oil (gravity fed) drain efficiently, you'll ruin your turbo. I learned it the hard way. Use at LEAST -10 AN or bigger. You can fit AN -12 on the drain side.

J

Marcel Burkett

Are you sure about that ? , what is the actual bore size of the carb jet ? , I happened to put my hands on the oil feed for the twin turbos and the line size is 1/4" (-6AN) and the bolt at the inlet at the turbo has a 3/16" (little larger than -4AN) bore and there are two of them!!!!. Please clarify this I dont want to blow my engine or my turbo !!!. I am thinking of going with a 1/8" I.D. NPT fitting.

peejay

dumb question then - would 3/16" line be too large then? i can make a restriction if necessary. i was planning on running 3/16" hardline directly from the oil filter tower (drilled, tapped, & fitted) to the turbo.

AJatx

iTrader: (1)

I used 1/4" NF tap for the Holley jet. You can look up the drill size needed for 1/4" NF (drill size #3).

I've done it on a 60-1 T04 and 62-1 T04.

J

1FastT2

iTrader: (1)

Isnt the restriction (1/4" NPT) at the turbo enough? It shouldn't matter what size the rest of the line is if its being orficed down at the turbo. I would think that the turbo manufactures would have made it thats way for a reason. Please correct me if im wrong.

Marcel Burkett

The 1/4" tap you used only describes the outer diameter of the hole , what is being questioned is the ID or bore of the line fitting or jet, in your case ,I think the #62 holley jet refers to the bore which is 1/16' or 0.62mm ,if this is really so I think I would be safe with a 1/8 bore fitting. And to answer 1FastT2 ,the 1/4 " size at the torbo is more than enough to supply it but remember we have to deal with a high oil pressure ,these turbos are ment for diesels which run a lower oil pressure ,hence the larger bore .

AJatx

iTrader: (1)

Marcel, sorry for not understanding your first question.

The Holley jets are in thousandths of inch.
It's NOT 0.62mm, but 0.061" for Holley Jet #62.
Ol' English system....

J

peejay

Actually the jet size has nothing to do with the orifice diameter... some jets are close, but the jet size correlates to how much fuel will flow through the jet. Some jets have the same orifice diameter as the size above and the size below, but the shape of the hole is different so flow is different.

Rutt

The reducer used on turbos over here decrease the volume more than the psi. When there is too much volume the center housing overfills becomes pressurized resulting in the oil flowing past the seals. Even if you used a -16 return a center housing can overfill if the inlet line is too big. Think about this for a sec: If you reduced a fire hose down to a garden hose would you get less psi or less volume? If you say "less psi" you need to re-think this!

AJatx

iTrader: (1)

The jets are rated for flow rate, but the part number does correspond to the bore size of the jet in mils.

Rutt, true about the blow-by if too much oil is fed into the CHRA and it cannot adequately flow the oil out of the drain line. The point is to think about your feed and drain lines and balance it.

Marcel Burkett

Can A #64 or #65 jet work (60 and 62 unavailable) ??.