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Solutions for performance RB problems


Z24O

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Wasn't able to edit my other post so hear is a mini version

 

Problem 1) Cranks (other than RB26 in the r33 and r34) only have the small oil pump drive on the snout.So if you are running a GTR/N1 oil pump then the drive is almost certain to crack leading to grenading the whole engine.

Solution- Fit a crank collar made out of machined 4140 steel.Your crank snout will need to be machined down to fit the collar over,it comes with a spec sheet for the dimensions and tolerances,just provide this to any competent machine shop as it is simple to do.

Cost- US$100 per collar (one required)

 

Problem 2) Excessive oil build up in the cylinder head starves the sump leading to spun bearings &/or catastrophic engine failure.

Solution- Replace the core plug in the rear of the head with an interference fit -8 or -10 aluminum fitting and run a drain line back to the sump.To fit,put the fitting in some cling wrap and leave it in the freezer over night,remove the top core plug in the rear of the head,place a 19mm socket to protect the threads over the fitting and tap the shoulder in.Voila

Cost US$50 per drain fitting (one required)

Problem 3) Running higher than factory boost causes an excessive build up of crank case pressure in the cam covers often leading to a forcing of oil past the turbo into the intake tract,using excessive oil,causing detonation and smoking exhaust under boost.

Solution- Proper ventilation of the crank case pressure by installing -10 oversize fittings and hoses in the cam covers.

Cost US$50 per fitting (one-two required)

 

If you are running a standard RB Turbo you may well not have any of the problems I have noted above...(although the forums are littered with tails of woe from guys with r32 RB26's that have spun bearings or lunched motors:icon11:)

However if you have upgraded to a bigger oil pump,bigger turbo, bumped up the boost or like to drive your RB on the raggedy edge then the above mods are cheap insurance and peace of mind.

 

To say that there are similar,possibly cheaper ways of achieving these mods by resourceful guys,but the above mods are well proven and guaranteed to fit and work for those who want a simple fix-it package.

Orders over US$150 qualify for free worldwide shipping.

Payment is by Paypal

PM me if you need further info or want to order anything;-)

Crank collar

crankcollar.jpg

Oil drain fitting

Fitting3.jpg

Fitting1.jpg

Fitting4.jpg

Cam cover fitting

Rockercoverfittingfordashfittings.jpg

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Is it a lack of a PCV system that causes the oil buildup? I see the same problem with my VG30ET's clogged PCV and I have since removed it in favour of a catch can that uses the vaccum from the compressor inlet to pull from the valve cover, with a breather on one of the valve covers to bring fresh clean air into the crank case instead of recirculating.

 

If this is not how it's done, can you tell us what the full solution for problem 3 is? where do these fittings go? across from eachother? or are you just making the factory provisions larger.

 

Thanks.

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Is it a lack of a PCV system that causes the oil buildup? I see the same problem with my VG30ET's clogged PCV and I have since removed it in favour of a catch can that uses the vaccum from the compressor inlet to pull from the valve cover, with a breather on one of the valve covers to bring fresh clean air into the crank case instead of recirculating.

 

If this is not how it's done, can you tell us what the full solution for problem 3 is? where do these fittings go? across from eachother? or are you just making the factory provisions larger.

 

Thanks.

 

precisely,you need bigger breathers running into a catch can,the pcv valves are way too restrictive when upping the boost (think of it as twice the air flow into the motor requires twice the ventilation) especially on the rb covers that just run one vent valve (theres a guy on this rb forum that i posted in recently that discovered this,effectively the boost was pushing oil past the turbo shaft seals into the compressor/turbine and smoking out the exaust)

 

i ran my breather pipes into a filtered catch can (filled with stainless steel pot scourers:icon52:)that was also vented to atmosphere via a K&N mini filter and ran a drain tube from the bottom of the catch can back into the sump

 

this way there is no backpressure to slow the oil flow down,the stainless 'filter' prevents any oil spraying up and blocking the K&N filter and you don't have to keep checking that the catch can isn't full of oil

 

i am no expert but i wouldn't be running the crankcase ventilation back into the intake side (under vacuum into the compressor) as i would be worried that the oil vapour may encourage detonation

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precisely,you need bigger breathers running into a catch can,the pcv valves are way too restrictive when upping the boost (think of it as twice the air flow into the motor requires twice the ventilation) especially on the rb covers that just run one vent valve (theres a guy on this rb forum that i posted in recently that discovered this,effectively the boost was pushing oil past the turbo shaft seals into the compressor/turbine and smoking out the exaust)

 

i ran my breather pipes into a filtered catch can (filled with stainless steel pot scourers:icon52:)that was also vented to atmosphere via a K&N mini filter and ran a drain tube from the bottom of the catch can back into the sump

 

this way there is no backpressure to slow the oil flow down,the stainless 'filter' prevents any oil spraying up and blocking the K&N filter and you don't have to keep checking that the catch can isn't full of oil

 

i am no expert but i wouldn't be running the crankcase ventilation back into the intake side (under vacuum into the compressor) as i would be worried that the oil vapour may encourage detonation

 

good point with the oil vapour / detonatoin. I guess to make things simpler I am going to buy another breather and mount it atop my catch can (also filled with pot scourers :D

 

I bought a thermos for 15 bucks in a 2 pack, fittings for 10 dollars, plus a drain that can be mated to a brake line flare that I can run down the side of the car with a petcock drain valve that I can just flip to the side and allow drain from the brake line exit. so around 20 bucks in total, with a free thermos to keep my Green Tea (JDM, y0!) warm.

 

I had the oiling issue with the Z31 PCV valve never being replaced, and also pushing oil passed the seals and coking the turbo shaft seals.

 

I had the turbo rebuilt with a 360degree thrust washer and a step/stagger gap turbine seal ring for super longevity.

 

cost me about 480 in total, but now I have a brand new turbo and the engine is all factory so it should run great with the new head porting job and no EGR/PCV system to contaminate the system.

 

It's amazing what kind of damage a 4 dollar emissions control device can do to a 2000 dollar + part.

 

The PCV was SO bad that the driver side head was bronzed nicely, and the passenger side head with the PCV was covered in so much soot and oily residue that it looked like it was deep fried in peanut oil and batter with a light coat of chocolate sauce.

 

here's a picture:

 

_dsc1361828.jpg.xs.jpg

 

far left is the cylinder closest to the PCV, If I am not mistaken.

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haha Careless,you crack me up with your gastronomical descriptions

green tea,batter,chocolate,peanut oil

whenever i look at problem engines all i see is sh*t,lol

 

ahaha, you should have seen the doodie that some rat must have shoved underneath the lower intake to keep warm.

 

little leaves, a small leak from the intake tract making the pcv oil drip down into the same area. I was left with a nice "turd like" composition of mulch.

 

I sprayed the "valley" with gold paint so i can shine a flashlight in there to see if it's leaking, and I'll be putting a mesh on the back side where the coolant return pipe goes so that it doesn't happen again.

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I have an R34 Neo RB25DET, not sure if it's an early one or a late one, but is there a way to find out if I need the crankshaft mod done without taking the oil pump off?

 

all rb25 variants run the short snout oil pump drive,this is ok unless you switch to the N1/gtr/RB26 oil pump

so this crank collar is advised for all RB's except the r33/34 RB26's which already have factory long snout oil pump drives

hope this clears up any confusion;-)

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Can also supply these brass oil restictors for those that want to use them.Brass much better than the cheap mild steel Jun ones:grin:

Can be supplied drilled to your personal specs as well at no extra charge.

US$30 a pair including worldwide post.

oilrestrictors.jpg

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