RB30DET TEETHING PROBLEM-Guru needed

[Cubes]

The RB30 actually has smaller oil head oil restrictors than the RB20DET/RB25DET.

My R32 RB20DET and the stock dash guage used to drop to zero and show the redlight when jumping hard on the brakes.

The RB30DET does this also.

It flashes on for a fraction of a second. But its scary enough I don't do it.

I suspect it 'may' be the stock guage playing up under hard brakes as the rb20det clocked ~170,000km's and was still fine. I'm not going to try my luck though.

[RB30-POWER]

The engine i put into my brothers R31 doesn't have the oil light coming on at all under heavy braking.

However it obviouslly uses the R31 sender and dash guage.

I always fill the RB30 to the H mark as the H mark is still along way from the sump baffle and crank seals. So over filling on the dipstick a little is not much of an issue on the Rb30 engines.

I suppose if your front end dives a bit and you are under heavy braking and don't have much oil in the sump it could move forward and uncover the oil feed pipe allowing air to be sucked in and oil light on.

I also stuck with the factory RB30 oil restrictors. (Top end seems to be getting enough oil, no noisy hydraulic lifters or anything, which would be a sign of low oil pressure or volume)

[MonstaS4]

the oil drain for the turbo return on an RB30 block is simply a big hole drilled through the block above the level of the oil in the pan. i don't know what you guys are on about :confused: it's exactly the same as if it went into the sump, above the oil level of course.

I'm not sure about R32's but R33 heads have an external oil drain which some of us have teed into the turbo oil drain. I can't see this as being a problem though.

[Cubes]

Ahhh.. I run the R32 RB25DE head.

[the_tonkau]

Cubes, interesting...very interesting. Like me now, sounds like you are suffering from oil surge. Don't see to many faulty oil pressure senders. If it was dodgy, I would think that you would be lucky get 170K klm's out of your rb20! In my situation, I was hoping that if I plumbed in a separate oil drain for the head into the side of the sump and got rid of the shared oil drain there would be enough flow back into the sump to stop my surge problems under hard braking after sustained high revs. If your setup has the same surge problems WITH the proper oil drains AND with a standard oil pump, I would think that i would be wasting my time trying this and should move onto the next solution and fit a larger/better suited sump pan.

[R31Nismoid]

It flashes on for a fraction of a second. But its scary enough I don't do it.

 

I suspect it 'may' be the stock guage playing up under hard brakes as the rb20det clocked ~170,000km's and was still fine. I'm not going to try my luck though.

tried filling it a bit over the full marker ?

to the top of the "F" and then seen what happens?

[Sydneykid]

My 20 cents worth...

We have found that at sustained high rpm (5500 rpm plus) far too much oil gets trapped in the cam covers. What we do;

1. Block off one of the oil supplies to the cylinder head.

2. Enlarge the return passages to the sump

3. Fit an external drain from the rear of the cylinder head to the sump

4. Always run a filtered catch can (filter on top and filled with stainless steel wool)

5. Never run the PCV back into the inlet

6. Use large diameter hoses from the cam covers to the catch can to keep the air flow velocity down

7. Don't rev the engine on mineral oil, use a heavy grade synthetic (Castrol Formula R 10W60 in our case)

8. We always run a winged and baffled sump with one way doors on all circuit cars. Drag cars have a simple vertical extension with a surge plate at the rear and the front.

[StockyMcStock]

I'm not sure about R32's but R33 heads have an external oil drain which some of us have teed into the turbo oil drain. I can't see this as being a problem though.

jesus, i just found what you're talking about on my R33 head. didn't even realise what it was! what do i do with it, must it be returned to the sump somehow or can i get away with just closing it up? :confused:

[RB30-POWER]

I've seen people with it crimped shut.

However i guess its there for a reason, so i always tee it into the turbo oil return for simplicitys sake.

I reckon fark all oil probally goes down it anyway, always seem dry. Head has an internal drain gallery anyway. I think its more for the extra oil from the VCT supply that needs draining away, as the non-vct heads don't have it.

[StockyMcStock]

yep that would make sense - my VCT is not going to be hooked up anyway and the car will NEVER see sustained high RPM work - street driver only. i figure after 5 seconds of > 4000 rpm the car will be going quite fast anyway.....

[the_tonkau]

Real world solutions are what we are after, thanks sk. Anyone other than high energy make oil pans for the rb?

A. Block off one of the oil supplies to the cylinder head

I assume this is internal and would have to be blocked off during the build?..too late for me that one.

Just a reminder boys, I would be less worried about engine smoking and oil burning and more worried about low oil pressure @ mucho revs!! Can't think of anything worse to kill or shorten the life of an engine....Right, my new mission is to improve flow from the cam covers back to the sump.......Will keep everyone informed on the solution........

Thanks again team.

P.S Anyone done a sump change WITHOUT the engine coming out?

[Skyrine-Dave]

Hi Guys,

I am starting to get really concerned, but im hoping its over nothing...

This is the second time now when giving my car WOT in 1st, and all the way thru 2nd... just as i am about to change into 3rd at high RPM blue smoke just trails behind the car and fills the cabin. Its definately not tyre smoke!

Now after about 5 mins the smoking goes away, i pop the bonnet and there is oil all over the cam covers, turbo, exhaust. (This is due to my dodgyness with the breather hoses, regardless it still proves a point that a fair bit of oil is coming out the cam breathers)

Now my RB20 used to do this, but i always thought that was because the rings were shagged... and i hope that is not the case with my RB30DET!!

Anyway after reading Garys (SK) posts I dont comply with:

* dont have a catch can with filter

* revving it on mineral cheap crap oil

I also read the excessive oil in the head when greater than 5500rpm.. I can tell you now I held 2nd gear above 5500rpm for about 10seconds or so...

I looked at my head and there is a flange blocked off... could this be an extra oil drain??

[QQQQ]

The more research i do on this problem the clearer it looks. These engines have a real tendency to flood the top end with oil with any sort of high revs and need mucho oil return paths and probably a bigger capacity sump for motorsport applications. I can't believe that the major oil return path from the head to the sump on your car has been BLOCKED OFF!! Ahhhh. If you are in my boat and using a S1 vl block (1 oil drain available) you will have to tee it into the turbo oil return line or run a special drain into the sump, or if you have a S2 vl block (2 oil drains available) you should be able to run it into a spare oil return at the bottom of the block. Which ever way you solve it, do it soon. Hot engine bays and excess oil spraying arounbd equals fire.

[RB30-POWER]

The Series 2 block does not have an extra oil drain. It has one only!

That plate that is covered is the extra drain that most people are plumbing into the turbo oil drain for simplicitys sake.

I would be suprised if it was the problem. But plumb it back for peace of mind.

[RB30-POWER]

Skyrine-Dave,

What size oil retrictors are you using in the block (head oil restrictors) and the VCT feed line?

[Cubes]

RB30-Power.

This oil drain in the block.. I have 2 little copper looking tubes that drain off in to the sump.

I have an 88 VL Commodore Wagon block.

Bl4ck32 has just had his tuned up recently, no problems with blowing oil smoke from his.

He recently made 218rwkw from a small rb20det t3/4 on 16psi.

Definitely sounds as if its an R33 RB25DET head thing.

[Skyrine-Dave]

I am making 256rwkw on the run in tune.

I only seem to have this problem when powering HARD thru 1st and 2nd, soon as 2nd gear is over the smoke comes and the oil has sprayed out.

I am NOT running VCT

[RB30-POWER]

 

This oil drain in the block.. I have 2 little copper looking tubes that drain off in to the sump.

I have an 88 VL Commodore Wagon block.

Cubes,

If you have two, one must be tapped as an extra, this pic shows the single drain from the turbo. (Why would the RB30ET have two, it doesn't need two?)

[Cubes]

I think its definitely an RB25DET issue.

I have no external head drain in to the sump.

The only oil drain I have are the 2 internal ones that run in the block as standard.

With the sump off you can see the oil drain copper looking pipes on the edge of the block where the sump bolts are between cyl 1 & 2 and cyl 4 & 5.

I'm not talking external, internal galleys that drain the oil from the head.

As I said previously our engine builder checked it out and said there is going to be zero oil drainage problems. I'm unsure if he fiddled to ensure so or not as I did mention to him how the GTR's throw the oil in to the head at high rpm.

[MonstaS4]

Just a thought..........If the smoke dosn't appear until you change from 2nd to 3rd is it possible the vacuum created through the PCV when you shut the throttle is sucking excess oil (due to no external drain) into the space above the baffles. But instead of actually sucking it through the PCV, it is blown out the breathers?