R33 Gtr

[tom9999]

hi guys,

I recently have spun a big end bearing and i just want to know how to help prevent it from happening again.

These were the mods when it happened:-

ACL race bearings

N1 oil pump

blueprinted bottom end

Castrol 5w-30

Is there anything i should do or is it just bad luck/motor not put together probably

cheers Tom

[TommO]

Was it tracked? Any idea of there were oil control mods done to the motor?

My understand is that bearings like that go due to lack of oil.

[tom9999]

nah its just a street car and i dont know about oil control mods, what can you get???? its got 23,000km on the motor

[R338OY]

you can get a baffled sump.

There's other stuff but i can't remember. GTR owners will know of the ins & outs of RB26 oil issues

Hope you get it sorted mate.

[moobaque]

Getting a baffled sump will only help with keeping your oil cooler (but upgrading to an aftermarket sump will generally mean higher capacity which is a good thing) and your problem has stemmed from lack of oil.

The simple fix is to overfill your oil 500ml - 1L above the full marker but this is generally just a precaution for track going vehicles.

considering your car is street only id be wondering if there was some sort of blockage or your oil pump failure. This really shouldn't occur on a street only car.

[R338OY]

On that note i've heard of one GTR tracked with 8L of oil.

[Duncan]

if you haven't hit the track and you do regular oil changes, sounds like something wrong with assembly, although it did last a long time for that.

[Blitz]

Getting a baffled sump will only help with keeping your oil cooler (but upgrading to an aftermarket sump will generally mean higher capacity which is a good thing) and your problem has stemmed from lack of oil.

The simple fix is to overfill your oil 500ml - 1L above the full marker but this is generally just a precaution for track going vehicles.

considering your car is street only id be wondering if there was some sort of blockage or your oil pump failure. This really shouldn't occur on a street only car.

Sorry, but you have missed the point of having a baffled sump - The point of the baffles isn't to keep your oil cooler, but rather to prevent oil starvation under hard cornering/load, which is particularly common at the track.

Ideally, anyone building an engine should be at a minimum fitting sump baffles, a good quality oil cooler, and an upper oil gallery restrictor.

[tom9999]

what oil should i be using to help prevent this happening again??? also would keeping the oil cooler help. what temperature should it be at??

[Blitz]

what oil should i be using to help prevent this happening again??? also would keeping the oil cooler help. what temperature should it be at??

Yes, keeping the oil cool is a priority.

Which oil you choose depends on your engine and its condition.

If the oil gets too hot, it gets too thin and you will run the risk of spinning a bearing again.

Personally I run Motul 300V Chrono, however given that my GTR takes 10 litres per change with my larger sump and cooler setup, it makes for expensive oil changes!

An oil cooler really is a must have on a modified GTR.

[tom9999]

yeh thought so i opened the oil cap and there was lots of steam???? and its was full

[Blitz]

yeh thought so i opened the oil cap and there was lots of steam???? and its was full

Not good, what oil have you been using? How often are you changing it?

[tom9999]

Castrol 5w-30, well i drove from melbourne to townsville and did a change asap and then 3 days later it went but usally 5000km

[Blitz]

Castrol 5w-30, well i drove from melbourne to townsville and did a change asap and then 3 days later it went but usally 5000km

5w-30??????????????????????????????

[R31Nismoid]

IMO - Baffles - waste of money as its only fixing another problem indirectly.

For a street GTR, with the RIGHT head modifications to stop the oil starvation in the first place... negates the need for a sump.

Heavily tracked GTR's here (350rwkw style) ran stock sumps without problem, so can you for a street car

Read the FI Guide (its a sticky), and in there it contains a link for Oil Control in RB's.

If you get that right, and have it rebuilt correctly, there is no reason it should die.

I would say your motor either wasn't assembled correctly or you ran low on oil at some point possibly. Likely bet is motor assembly.

Castrol 10/60 is what i would be using in a built motor personally, been run in all of mine for the past 4 years, no issues

5/30 is probably part of the issue

[R34GTFOUR]

what power are you putting out?? what rods are you using? what rod bolts/studs are you using??

pushing big hp on stock rod bolts "can" stretch and lead to big end failures, although oil control problem are common in gtr's as stated

A spun bigend on a 20k km built engine driven on the street = something very very wrong

[giant]

maybe oil pump let go?? had you revved it hard or big launch.?

[N1GTR]

Do you hit the rev limiter much?

[proengines]

Detonation/pre-ignition is probably the biggest killer of conrod bearings on GTR's when the boost is wound up. Most of the time you'll find there's no oil pump problem etc.. Have a look at the other conrod bearings, if they have marking on the upper bearing from 10 thru 1 o-clock it's usually a good sign of detonation. It happens because the mixture fires too early and the piston is pushed back down the bore while the crank is still trying to push it up, this squeezes out the oil film and you have metal on metal contact between the crank journal and the bearing.

[TTT]

Blitz - isn't 5-30 what the nissan recommendation is?

and if it is a freshly rebuilt engine (20K kms), then is it really a problem?

more info on what/when it happened would be good too.

idling along freeay at 110kms or giving 1st and 2nd a good rogering?