Comman Problems With Rb25det

[old mate]

i did a search and went back to about mid 07 and thought no point going further back due to development. or i typed the wrong shit in.

any ways i have an rb25det s1 pulled down and it will be rebuilt with pistons and rods, bearings, studs, gaskets of major brands. the motor will see drift work plus track/grip. is there anything i should spend my money on to avoid say oil problems or somthing simialr which is easy to fix but can cause big problems if i dont.

any help you can give would be great.

cheers, steve.

[The Mafia]

there is a massive thread based on the oiling problems that plague the RB25.

I'd find it and do everything that it suggests, because most of the problems arise when doing track work, in high revs.

[old mate]

oh cool dude yeah if you could find it for me i would apreciate it. dont really surf this site too often.

[NYTSKY]

Dry sump will fix everything

But upgrade the oil pump

Good catch can and breather setup

Maybe head to sump oil drain

500mls extra oil.

[The Mafia]

Dry sump will fix everything

But upgrade the oil pump

Good catch can and breather setup

Maybe head to sump oil drain

500mls extra oil.

dude, putting a bigger oil pump on, and not doing the rear head drain, or blocking the rear oil feed in the head makes the problem worse.

The whole problem is oil pooling in the head do to bad drainage at high RPM. If you put a bigger oil pump on, it will simply pump more up there and into the catch can, creating a disaster. I've seen this happen - GTR oil pump on a RB25 with no extra drains... or the rear feed blocked. Blew most of the oil into the catch can.. and then when the sump was starved... bang.

You're giving bad advice I'm afraid...

Edited December 23, 2008 by The Mafia

[MBS206]

dude, putting a bigger oil pump on, and not doing the rear head drain, or blocking the rear oil feed in the head makes the problem worse.

The whole problem is oil pooling in the head do to bad drainage at high RPM. If you put a bigger oil pump on, it will simply pump more up there and into the catch can, creating a disaster. I've seen this happen - GTR oil pump on a RB25 with no extra drains... or the rear feed blocked. Blew most of the oil into the catch can.. and then when the sump was starved... bang.

You're giving bad advice I'm afraid...

The advice I've been given by most engine builders is not to restrict the oil getting up top. It's all in freeing up getting it back down to the sump.

IE, you REALLY want a good drain setup to get it out of the head. Then, you're all sweet.

The issue is only at high RPM, so who knows what it's doing when you're blocking an oil feed off and sticking to low RPMs. You might be starving the head of oil slightly.

[JMW]

I did see a drain set-up for RB30 heads on ebay, was simply a fitting tapped into the rear of the head for extra drainage. Would thios also work on an RB25?

[MBS206]

I did see a drain set-up for RB30 heads on ebay, was simply a fitting tapped into the rear of the head for extra drainage. Would thios also work on an RB25?

I'm just using the fitting that TUF_RX3 from here made, which is press fitting into the back of the head.

Others drill and tap a fitting in.

[JMW]

Sounds like the go! I know some of the V8 brigade use a similar set up when running high volume oil pumps too

[The Mafia]

The advice I've been given by most engine builders is not to restrict the oil getting up top. It's all in freeing up getting it back down to the sump.

IE, you REALLY want a good drain setup to get it out of the head. Then, you're all sweet.

The issue is only at high RPM, so who knows what it's doing when you're blocking an oil feed off and sticking to low RPMs. You might be starving the head of oil slightly.

Well, the GTR have a blocked feed from the factory, and a restricted feed up the front. So less again.

I'm pretty sure SK has said that even with a blocked feed at the back, there is still more than enough oil for the hydraulic lifters in the RB25.

[old mate]

so should i do something like an n1 oil pump and then some how sort out better drainage back to the sump at the back of the motor?

[woolls]

http://www.skylinesaustralia.com/forums/Oi...amp;hl=oil+feed

http://www.skylinesaustralia.com/forums/Rb...amp;hl=oil+feed