Jump to content
SAU Community

Recommended Posts

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

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/
Share on other sites

  • Replies 49
  • Created
  • Last Reply

Top Posters In This Topic

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.

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655137
Share on other sites

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.

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655278
Share on other sites

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.

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655326
Share on other sites

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

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655372
Share on other sites

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

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655410
Share on other sites

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.

Link to comment
https://www.sau.com.au/forums/topic/206613-r33-gtr/#findComment-3655710
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Ah right. Maybe my rb just loves chewing through batteries lol.
    • On the R34 can't you just unplug the IACV? This is the way I've always done it on the R33. Disconnect IACV, get it idling around 650rpm, and then do a power reset on the ECU to get it to relearn idle (factory ECU).   The big reason no one has touched on as to why you'd want to get the base idle right, is that it means the computer needs to make smaller adjustments to get a good idle at 700-750rpm.   Also, cleaning the IACV won't normally make the car suddenly idle lower or higher. The main issue with the IACV gumming up is that the valve sticks. This means the inputs the ECU gives, aren't translating to changes in air flow. This can cause idle choppy ness as the ECU is now needing to give a lot of input to get movement, but then it moves too far, and then has to do the same in reverse, and it can mean the ECU can't catch stalls quickly either.
    • 12.8 for a great condition, fully charged battery. If the battery will only ever properly charge to about 12.2V, the battery is well worn, and will be dead soon. When I say properly charge, I mean disconnect it from the car, charge it to its max, and then put your multimeter on it, and see what it reads about an hour later. Dieing batteries will hold a higher "surface charge", but the minutest load, even from just a multimeter (which in the scheme of things is considered totally irrelevant, especially at this level) will be enough over an hour to make the surface charge disappear.   I spend wayyy too much time analysing battery voltages for customers when they whinge that our equipment (telematics device) is causing their battery to drain all the time. Nearly every case I can call it within about 2 months of when the battery will be completely dead. Our bigger customers don't even debate it with me any more ha ha ha. A battery at 12.4 to 12.6 I'd still be happy enough with. However, there's a lot of things that can cause a parasitic draw in a car, first of which is alarms and immobilisers. To start checking, put your multimeter into amps, (and then connect it properly) and measure your power draw with everything off. Typical car battery is about 40aH. Realistically, you'll get about half this before the car won't start. So a 100mA power drain will see you pretty much near unstartable in 8 days.
    • Car should sit at 12.2 or more, maybe 12.6 or 12.7 when fully charged and happy. If there is a decent enough parasitic load then it will certainly go lower than 12.2 with time. You can't beat physics.
    • Ok guess I can rule out the battery, probably even the starter and alternator (maybe) as well. I'm gonna clean those leads and see what happens if it's still shit I might take it to an auto electrician. Unless the immobiliser is that f**king heavy, but it shouldn't be.  If I start the car every day, starts up perfectly never an issue. Isn't 12v low, shouldn't it be around 12.5v?
×
×
  • Create New...