Turbo Oil Return Temperature

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Al2O3

Al2O3

Well-Known Member
Full Member
Posts
11,023
Location
North of the Wall
I'm contemplating making my own return pipe from the turbo (Defender 90 300Tdi)
I've got some silicon hose rated to 220 Celsius.
Anyone any idea what temp the oil will be as it exits the turbo?
IIRC the water stat opens at 88C and the water sits at 90-95 ish, but I don't know what temp the oil stat opens or what temp the oil sits at. I would have thought it's at it's hottest point as it exits the turbo?
 
I have no idea, but quite a few trucks I see have a silicone flex hose in the oil return pipe, some are 11 yrs old with 1.5 million k on the clock, which I guess is enough of a road test:D

Generally oil temp is higher than coolant temp but not massively so, so your 220 degc hose should be safe, rigid pipe will need a swage on ti to stop the slippery silicone hose popping off.
 
lynall said:
I have no idea, but quite a few trucks I see have a silicone flex hose in the oil return pipe, some are 11 yrs old with 1.5 million k on the clock, which I guess is enough of a road test:D

Generally oil temp is higher than coolant temp but not massively so, so your 220 degc hose should be safe, rigid pipe will need a swage on ti to stop the slippery silicone hose popping off.
Click to expand...
Cheers, lynall.
My plan is to use one of these
69F1B64E-09C9-488D-A0B4-CBBB6EEFB8B0.jpeg

If I saw one end off here
C909141E-6EA3-4B8C-AC6C-1D62FE6863BD.jpeg


And the other end off here
CAECFE8C-6B03-4ED9-9545-BA0E409642B8.jpeg


That gives me a lip at both ends to put the jubilee clip above. What do you reckon?
 
I used to work with industrial turbo compressors and localized temperature at the bearings was much higher than the oil temperatures in the sump, but of course they were not driven by an expansion turbo in the exhaust system.
I think that 220 ought to be sufficient, especially if that is given as working temperature, there should be some capacity for safety built in.
 
Al2O3 said:
Cheers, lynall.
My plan is to use one of these
View attachment 221045
If I saw one end off here
View attachment 221046

And the other end off here
View attachment 221047

That gives me a lip at both ends to put the jubilee clip above. What do you reckon?
Click to expand...
Those ends are crimped by the sleves, do you have a small grinder like a Dremel to carefully split the crimps along the axis of the pipe then try to pull out the fittings from the flexible section?
 
raywin said:
Those ends are crimped by the sleves, do you have a small grinder like a Dremel to carefully split the crimps along the axis of the pipe then try to pull out the fittings from the flexible section?
Click to expand...
Funny you should say that, but a mate gave me a Dremel a few weeks ago! Great idea, I’ll give that a go tomorrow. :)
 
raywin said:
I used to work with industrial turbo compressors and localized temperature at the bearings was much higher than the oil temperatures in the sump, but of course they were not driven by an expansion turbo in the exhaust system.
I think that 220 ought to be sufficient, especially if that is given as working temperature, there should be some capacity for safety built in.
Click to expand...
220 is its upper value on its temp range. Sorry, didn’t fully twig that before.
 
They’re off using the Dremel and a hacksaw
8D4156E0-C959-40AB-9ABC-953CAB1D5813.jpeg

caught both ends a bit with the Dremel but it should be fine with a couple of jubilee clips on each end. @lynall and @raywin I much appreciate the advice about the swaging and getting them off, cheers gents. :)
 
Al2O3 said:
They’re off using the Dremel and a hacksaw
View attachment 221114
caught both ends a bit with the Dremel but it should be fine with a couple of jubilee clips on each end. @lynall and @raywin I much appreciate the advice about the swaging and getting them off, cheers gents. :)
Click to expand...
Looks like you did a good job there.
Shouldn't be much pressure on the line it should only be subject to a little back pressure from the crank case , and if it works maybe you can make up the Mk2 improved version.
Good luck
 
raywin said:
Looks like you did a good job there.
Shouldn't be much pressure on the line it should only be subject to a little back pressure from the crank case , and if it works maybe you can make up the Mk2 improved version.
Good luck
Click to expand...
Yes, hopefully very little pressure and nothing the jubilee clips should have bother with. I just need to go out and get some now! Light rain with bursts of very heavy showers here, so I'm going to have to wait for the weather before I can try it out :(
 
These fittings are only 9mm diameter, which isn’t great for turbo oil return pipe.
552D5E11-5E93-4880-9152-12390C1659DE.jpeg

It actually looks bigger there than it does in real life.
 
May not help but you can see the TD5 turbo return on this picture it seems similar in size, look at the flange which bolts to the turbo, but I didn't measure it as the was no problem.

IMG_0598.JPG
 
If it was the original turbo oil return pipe that you cut up, then yes the size will be just fine.

Dont forget the silicone hose will need to be the reinforced type, ie have string/webbing embedded inbetween the layers of material, not so much for the pressure, more to keep it together in what is a pretty harsh enviroment.
 
mick 1986 said:
What diameter is the original? Why are you looking at doing this?
Click to expand...
That is sort of the original. It’s an aftermarket one, Bearmach I think that one was.
I’m doing it because since my engine rebuild I’ve been burning oil. I can’t get the turbo return pipe to fit without kinking, so I think it’s restricting flow and the HP oil is being forced through the turbo in to the induction system.

raywin said:
May not help but you can see the TD5 turbo return on this picture it seems similar in size, look at the flange which bolts to the turbo, but I didn't measure it as the was no problem.

View attachment 221127
Click to expand...
Your pipe looks to be a bigger diameter than mine. I suppose that 9mm diameter must be just enough to allow enough oil through in normal circumstances. When mine has a kink in it I presume (Hope) it restricts it enough to make the oil back up.

lynall said:
If it was the original turbo oil return pipe that you cut up, then yes the size will be just fine.

Dont forget the silicone hose will need to be the reinforced type, ie have string/webbing embedded inbetween the layers of material, not so much for the pressure, more to keep it together in what is a pretty harsh enviroment.
Click to expand...
Yes, it’s an proper return pipe I’ve cut up.

Bugger, the silicone pipe I bought does not have reinforcing webbing in it :( Back online tonight me thinks :(

Anyway, been out in the rain to temporarily put the turbo back on and measure up for the pipe. So far it looks like this. With another of my return pipes for comparison
C50B06AD-DAA3-473C-800C-83F346272E6C.jpeg


Proximity to the exhaust is going to be another feckin problem, so I may need to fabricate some sort of heat shield.
 
Al2O3 said:
That is sort of the original. It’s an aftermarket one, Bearmach I think that one was.
I’m doing it because since my engine rebuild I’ve been burning oil. I can’t get the turbo return pipe to fit without kinking, so I think it’s restricting flow and the HP oil is being forced through the turbo in to the induction system.


Your pipe looks to be a bigger diameter than mine. I suppose that 9mm diameter must be just enough to allow enough oil through in normal circumstances. When mine has a kink in it I presume (Hope) it restricts it enough to make the oil back up.


Yes, it’s an proper return pipe I’ve cut up.

Bugger, the silicone pipe I bought does not have reinforcing webbing in it :( Back online tonight me thinks :(

Anyway, been out in the rain to temporarily put the turbo back on and measure up for the pipe. So far it looks like this. With another of my return pipes for comparison
View attachment 221131

Proximity to the exhaust is going to be another feckin problem, so I may need to fabricate some sort of heat shield.
Click to expand...

If you increased the diameter of the pipe, would that not starve the turbo bearings of oil? I’m thinking that there must be some form of oil pressure to make the bearings hydrodynamic, so if you remove the back pressure, will loose the hydrodynamic effect? I’m not sure it will if it has baffles inside the turbo oil ways, but I have never been inside them turbos.
 
mick 1986 said:
If you increased the diameter of the pipe, would that not starve the turbo bearings of oil? I’m thinking that there must be some form of oil pressure to make the bearings hydrodynamic, so if you remove the back pressure, will loose the hydrodynamic effect? I’m not sure it will if it has baffles inside the turbo oil ways, but I have never been inside them turbos.
Click to expand...
They have a high pressure feed, but the return flow returns to the sump via gravity and is not under pressure. Resistance to this natural return flow causes the oil to back up and so the HP oil can't get through the way it should and so squeezes through the turbo rings and in to the compressor.
 
You must log in or register to reply here.

Similar threads

cappers
Temp gauge reads hot when lights switched on....?
Replies
7
Views
1K
Rougharse Racing
Rougharse Racing
J
ZENITH CD175 TEMPERATURE COMPENSATORS HELPFUL INFO
Replies
8
Views
2K
hef19898
hef19898
DefendingLancashire
300TDI Four-parter: brake wear, lift pump / fuel filter, turbo, and bushes / squeaking
Replies
13
Views
472
miktdish
miktdish
T
Another temperature gauge problem
Replies
14
Views
2K
Twinnie
T
Al2O3
Oil Pressure in Different Parts of the Engine
Replies
8
Views
1K
Al2O3
Al2O3
Back
Top