1KZ-TE. How to get more oil pressure to rb25det turbo.

[1598cc]

Yes, its a diesel. Its in a surf towing a 2 tonne trailer..

Anyway, ive mounted up a rb25det turbo etc.. However im having problems with geting enough oil thru the tubro


Theres plenty of flow when the oil feeds disconnected, however once it goes thru the turbo the return is very minimal, like a trickle.. Tried a few different turbos so its no the turbo. Taken all restrictors out of the oil line. Can only imagine its pressure as apparently this engine has low pressure??

How can i get sufficent flow of oil thru the turbo.. have tried using around a dash 4 size line to the turbo, but still not enough ...

[sergei]

I doubt that engine has low pressure. Perhaps that specific engine has low pressure? Or maybe it has internal pressure regulator for turbo feed?

[1598cc]

Yeah ive heard that this model engine seems to have lower pressure, unsure on this tho.. Just needa figure a way to get some oil thru the dam turbo

[evil_si]

put mechanical guage in it and see what the actual pressure is to start with,
then if it is low you could increase the tension in the relief valve

[rollaholic]

dry sump!

[1598cc]

put mechanical guage in it and see what the actual pressure is to start with,
then if it is low you could increase the tension in the relief valve

Righto ill give it a shot.. Where could i score a relief valve.

Had an idea to use a larger oil feed hose, its currently 3mm, if i used a 8mm pipe you think thatd get more thru it? If the engine is already low pressure and the turbo is already acting as a mad restrictor would using a relief valve do much?


Ive still gotta ht18s in a20det exhaust housing lying around.. Being a non ball bearing turbo you rekcon thatd have less oil restriction going thru the turbo.. Seems rb turbos are restricted a shit load e.g. pour oil into the oil feed n takes a while for it a to go thru.

[1598cc]

dry sump!

Yeh , on a diesel 1kzte shitbox... Might just weld a wastegate to the windscreen.

[1598cc]

Just thinking simon, using a relief vavle, wouldnt that just pressuise before the relief valve, and after the valve the pressure would even be less?

[sergei]

Just thinking simon, using a relief vavle, wouldnt that just pressuise before the relief valve, and after the valve the pressure would even be less?

What he meant is increase tension in the relieve valve on the oil pump.
The relieve valve usually lives somewhere in the sump bolted to the block, I don't have diagram for KZ, but it could also be in the oil cooler (the water to oil cooler - sometimes oil filter bolts on to it).
What you usually do is either add washers under the spring or put stronger spring, so the valve will release oil at higher pressure.
Is the actual turbo ok? Has it ever been running before? It could be well gunked up.

[sergei]

http://www.toyodiy.com/parts/p_J_1998_T ... _1501.html

So it is on the side of the oil pump.

Before doing anything, see what is the actual pressure.

[1598cc]

Ah true never knew this. That would work and is a mint idea.

Turbo is fine ive got a few lying around and they all do the same.

Ill have a look around the net to find info about the relief valve, that could well be me solution, heres hoping.!

[1598cc]

http://www.toyodiy.com/parts/p_J_1998_T ... _1501.html

So it is on the side of the oil pump.

Before doing anything, see what is the actual pressure.

Ok thanks will check pressure today.


Any ideas if the relief valve is accesable without taking the sump off etc?

[evil_si]

yup thats the one i meant,
no point playing with it with out checking the pressure fist thou, at least you can start to pin point whats going on,


not familiar with the 1kz so not sure were it is, some are inside the engine. and invlove removing the sump, some are external,

sometimes they are gunked up, a good clean with break clean will sort it, the gunk can build up and prevent it from closing properly, thus holding it off the seat and allowing some oil bypass,

if its all intact and clean i would start by increasing the spring presure in the relief with a small washer between the spring and the 'relief piston', add 1 washer at a time intill you get the desired pressure,

down side is it can be a bit of mucking round especially if it involves removing the sump each time,

[1598cc]

Ok sweet. What sorta pressure should I be looking @ on idle, 20psi?ish

Will getta oil pressure gauge on it today.

[1598cc]

Aite, so im getting 30psi steady at a cold idle. So no pressure problems.. This is fukin weird, why is that a rb turbo just wont work. Ive tried 3mm and 6mm oil feed line, no restrictors in the banjos etc.. It should be pissing oil out the seals theoretically.

What do you think about chuckinga ht18 on it simon having a non ball bearing design may have less restriction thru the actual turbo, probly quite abit laggy but then again diesels move quite abit of air.

[allencr]

How can i get sufficent flow of oil thru the turbo...

If it is sufficient getting to the turbo, and the drain looks insufficient to you, it seems to me like the turbo has a clog or its clearances are too tight or that you shouldn't judge it compared to the other worn out turbos you've had experience with.
The relief valve may not be sealing properly & have a leak. If it does not, hot idle oilPSI =20-30, then F'ing with the spring will not do any good at all. It does not increase oil pressure, it raises the limit of oil pressure that is factory set keep the filter from bursting open or breaking the pump at high RPM.

[evil_si]

whats the rb turbo actually doing?
have you had trouble with them failing?
in theory if its got good oil pressure at turbo, and the drain is not on a funky angle or restrictive it should be good,

not sure on the HT18/T3, thou i had thoughts in the past about putting one on a 2.8 diesel,
bigger turbine and compressor than an rb25 turbo but a smaller exhaust housing, could be worth a shot

[1598cc]

How can i get sufficent flow of oil thru the turbo...

If it is sufficient getting to the turbo, and the drain looks insufficient to you, it seems to me like the turbo has a clog or its clearances are too tight or that you shouldn't judge it compared to the other worn out turbos you've had experience with.
The relief valve may not be sealing properly & have a leak. If it does not, hot idle oilPSI =20-30, then F'ing with the spring will not do any good at all. It does not increase oil pressure, it raises the limit of oil pressure that is factory set keep the filter from bursting open or breaking the pump at high RPM.

Sweet. Yeh checked all the turbos for blocks etc, ive 2 rb25 turbos, both doing the same. Can blow thru the oil feed but its quite hard , maybe twice as hard as the ct12b turbo, altho thats not ball bearing so assume itll have more restriction.

whats the rb turbo actually doing?
have you had trouble with them failing?
in theory if its got good oil pressure at turbo, and the drain is not on a funky angle or restrictive it should be good,

not sure on the HT18/T3, thou i had thoughts in the past about putting one on a 2.8 diesel,
bigger turbine and compressor than an rb25 turbo but a smaller exhaust housing, could be worth a shot

Ive just boogied up a manifold n exhaust with t3 flanges for the engine, so this is the first time itll be running , however its draining around say 2-300mls a minute from the oil return not nearly enough. Oil return is straight down etc, its a weird one.

Can only try the ht18 then, it must just be something with these turbos i have. Wacked.

[evil_si]

could try asking steve murch, he would probably have the best idea as to weather its turbo related or not, theres a few posts on here that he pops up in.

[sergei]

Have you measured pressure at oil feed for the turbo?
Perhaps it is restricted some how before the line?