Offroad-Express

Its a rb25det skyline turbo ball bearing.. Im running around a 3mm oil feed line, but the oil just trickles out from the oil return and i can hear that its not lubricating the turbo correctly so dont want to fuk the turbo.


With the oil feed not on the turbo it pisses out nicely.. Plenty of flow.


Any ideas what would be causes this massive lack of flow. Ive taken all restrictors out and its just a 3mm line from the block to the turbo.. Help!

out of interest only , why the upgrade in Turbo?
Ive been told the factory ones will handle 25psi no worries

You'll need at least 12mm tube, its gravety return so if the return pipe is to small youll start leaking oil out the turbo seals.

Ah, the oil return is 20mm wide, but the oil feed is 3mm wide.. Getting very little flow through the turbo.


Boost is totally different to flow.. Having 25psi boost on the standard turbo will keep way to much heat around the head. Having more flow through the engine allows for better power as its allowing the air to go through the engine quicker. Boost is a measure of resistance. The standard turbo is tiny. Adding more fuel on this turbos should give some decent results as im towing a 2tonne trailer

So ive been told the 1kz engine runs a low oil pressure, is this correct?

And if so how can i increase oil through the turbo

tarmac- wrote:And if so how can i increase oil through the turbo

There is lots of resistance in a small pipe.
Think of a stream and how the current is slower nearer the edges and faster in the middle. Well there aint much middle in a 3 mm pipe!

Install a bigger pipe and fittings. Ensure you don't use tight right angle fittings.

tarmac- wrote:Its a rb25det skyline turbo ball bearing.. Im running around a 3mm oil feed line, but the oil just trickles out from the oil return and i can hear that its not lubricating the turbo correctly so dont want to fuk the turbo.


With the oil feed not on the turbo it pisses out nicely.. Plenty of flow.


Any ideas what would be causes this massive lack of flow. Ive taken all restrictors out and its just a 3mm line from the block to the turbo.. Help!

if there is plenty of flow with the line off then there is possible a restriction in the turbo oil ports, or bearing has shifted and obscured the oil holes, try blowing compressed air up the return pipe, and see if any crap comes out the feed line,

cheers

pedro

IcedJohnno wrote:

tarmac- wrote:And if so how can i increase oil through the turbo

There is lots of resistance in a small pipe.
Think of a stream and how the current is slower nearer the edges and faster in the middle. Well there aint much middle in a 3 mm pipe!

Install a bigger pipe and fittings. Ensure you don't use tight right angle fittings.

with only a 3mm pipe there will be fark all going in to the turbo. Its like filling up a swimming pool with a garden hose compared to filling it with a fire hose. The garden hose might have the high pressure but there is still only a very small volume going in. Hence why your not seeing it come out as fast as it goes in. It needs to fill the swimming pool before it can drain out at a good rate. Do what he said and upgrade the line.

The standard size line is 3mm. Ball bearing turbos use even less however im still @ 3mm and have tried 6mm.

Ball bearing turbos use a 1mm restrictor inline, so the problem is not the line size.


The engine has done 250000ks, ive been alerted that the pressure relief valve maybe stuck slightly.. Can i access the valve without taking the sump off. Does anyone know where exactly it is?

Thanks

tarmac- wrote:The standard size line is 3mm. Ball bearing turbos use even less however im still @ 3mm and have tried 6mm.

Ball bearing turbos use a 1mm restrictor inline, so the problem is not the line size.


The engine has done 250000ks, ive been alerted that the pressure relief valve maybe stuck slightly.. Can i access the valve without taking the sump off. Does anyone know where exactly it is?

Thanks

Fair call I think Pedro's comments are on to it. Had not read that you have plenty of flow if the delivery pipe is not connected to the turbo.

bb turbos dont need pressure they need flow hence the 0.7-1mm restrictor ...as pedro has said check your turbo hasent got shit down it .....
its not hard tocheck if your engine has got pressure
1 it wont be fucked
2 put a pressure guage on it ...


if you have plenty of flow at the pipe befire the turbo and none afterwards ... it stands to reason the turbo is the issue

what makes you think the turbo is not getting enough oil ??
bb turbos make no more bearing noise without oil as with oil .. unless there toast

Maybe your grade of oil is too thick to flow through the restriction in the oil feed that your ball bearing turbo has compared to your old non ball bearing turbo.I have had this issue on a turbo petrol engine.