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Rb26 single turbo oil/water lines

WantGTR

By WantGTR,
in Engines & Forced Induction

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WantGTR Mentor

WantGTR

Posted
Posted

Hi all, 

Am going single turbo and am i a little unsure about the oil and water lines. See pick below

2018-02-06_08-14-12

Are the areas marked A the oil feeds? If so what are the thread sizes on the block? What size hose is best recommended?

The areas marked B are the oil drains correct?

In relation to water lines. Is it best to use the feed from the top rad house outlet?

In terms of recirculating the water, there is a water bypass tube under the inlet manfold, is it best to route the water to there or is somewhere else better?

Thanks for your help

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https://www.sau.com.au/forums/topic/473283-rb26-single-turbo-oilwater-lines/
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WantGTR Mentor

WantGTR

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18 hours ago, r32-25t said:

The front A is the oil feed and the A at the back of the block is the water feed 

and both the B are the oil returns 

Thanks! Does anyone know what the thread size is on the block for the water and oil feeds?

Also what size an hose is ideal?

sneakey pete Grand Master

sneakey pete

Posted
Posted

the top of the radiator is a water return... if you use that as your feed you're in for a bad time.
Out the block back into the top of the radiator is how i and a lot of others have done it, just weld/plug off the nipple under the plenum, then you have one less damn hose behind the head to worry about

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WantGTR Mentor

WantGTR

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2 hours ago, sneakey pete said:

the top of the radiator is a water return... if you use that as your feed you're in for a bad time.
Out the block back into the top of the radiator is how i and a lot of others have done it, just weld/plug off the nipple under the plenum, then you have one less damn hose behind the head to worry about

Thanks will do this.

WantGTR Mentor

WantGTR

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As i am going braided turbo lines i am removing the stock front oil drain screw in fitting and changing to an AN fitting.

Due to the angle of the drain you will need to remove the engine mount to remove this fitting if the engine is still in the car.....

  • 2 weeks later...
  • 2 weeks later...
WantGTR Mentor

WantGTR

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On 22/02/2018 at 1:22 AM, XGTRX said:

Don't forget to consider the need for a restrictor for your oil feed.  A $20 in line filter is also a good idea.

Thanks will remember this.

For water lines, an8 feed and an10 drain sufficient?

What size lines for oil feed and drain?? 

What thread size are the oil feed and drain threads on the block?

 

  • 3 weeks later...
WantGTR Mentor

WantGTR

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Posted (edited)

Right guys, incase there are more amatuers like me, on an rb26 block

Front turbo oil drain is 3/4 npt (first B in my pic)

Rear turbo oil drain uses a gt/gtx/efr oil drain adapter. Ie https://gcg.com.au/petrol-performance/performance-2/oil-drain-fittings-accessories/oil-drain-kit-gt-gtx-efr-series-10an-male-detail    (second B in my pic)

Oil feed is m12x1.25 (first A in my pic)

Water feed or return on the block is m14x1.5 (second A in my pic)

Fwiw i went 10an for the oil drain, 8an for water feed/drain and 4an for oil feed. Hope this helps anyone who is reading.

 

Does anyone know the thread size for the mac boost solenoids? I was sure they were m10x1.0 but the fittings dont really want to go in. Perhaps i need to clean the threads on the solenoid??

Edited by WantGTR
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GTSBoy Grand Master

GTSBoy

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Posted

Um.....MAC valves (the typical 35 series that are usually used in cars, and actually, most of the smaller MAC valves) are 1/8" NPT.  As you'd expect for an American product.

The 3/4" drain in an RB26 block, on the other hand, is sooooooo unlikely to be NPT (being Japanese, who realistically use BSP for everything).

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WantGTR Mentor

WantGTR

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27 minutes ago, GTSBoy said:

Um.....MAC valves (the typical 35 series that are usually used in cars, and actually, most of the smaller MAC valves) are 1/8" NPT.  As you'd expect for an American product.

The 3/4" drain in an RB26 block, on the other hand, is sooooooo unlikely to be NPT (being Japanese, who realistically use BSP for everything).

Are you sure about the mac valve? I took one of the fittings off, there arent many threads and theres no taper. I took the fitting to supercheap and tested it on the bolt size rack thing. Screwed in and out perfectly on m10x1.0

With the drain i used a speedflow fitting, part no 816-10-12. Looked the same as the stock drain thread and fits perfectly.

The fittings i have mentioned in the above post are currently on the car so i can confirm they work.

GTSBoy Grand Master

GTSBoy

Posted
Posted (edited)

There's really only 1 size at which BSP and NPT screw together properly.  That's 1/2".  It's not that they're exactly the same.....they are just the same to within the tolerances of the thread specs.  Other sizes, like 3/4, just go together like a single turn, or maybe 2, before they jam up.

1/8" NPT has an outside (tips of the threads) diameter of 0.405".  That's 10.3mm (close enough).  The thread pitch is 27 per inch.  That's really close to 1mm pitch (but it's not!).

So it looks like M10x1.0, because M10 is like 0.35mm smaller than 1/8" NPT, and there's no way that your average dinkus can see the difference between 25.4 tpi and 27 tpi.  But the profile of the threads are not the same.....so trying to screw them together is not a recipe for the threads to work the way they are supposed to and get you a good seal.

Edited by GTSBoy
iruvyouskyrine Grand Master

iruvyouskyrine

Posted
Posted
On 3/19/2018 at 8:30 PM, GTSBoy said:

Um.....MAC valves (the typical 35 series that are usually used in cars, and actually, most of the smaller MAC valves) are 1/8" NPT.  As you'd expect for an American product.

The 3/4" drain in an RB26 block, on the other hand, is sooooooo unlikely to be NPT (being Japanese, who realistically use BSP for everything).

Im sure the oil drain is 3/4 NPT which is the same as the gearbox drain/fill plugs.

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