Jump to content
SAU Community

Rb26 / 30 Knocking Sound W/ No Load, Big End Bearing? [Vid]

ST240

By ST240,
in Engines & Forced Induction

 Share

Recommended Posts

ST240 Enthusiast

ST240

Posted
Posted (edited)

The oil light came on idling at a red light the other night after some hard pulls, however my pressure gauge did not show a loss in pressure when the light was on (what causes the oil light to come on? Is it strictly a pressure loss? I later tinkered with the plug and it may or may not have been loose). I was a few blocks away from the house and I noticed this noise.

The sound in the video only shows up at around 2500 RPM briefly. It also doesn't seem to really be there when the engine is cold. Tomorrow I will cut apart the oil filter to see if I can find bearing flakes.

I'm really scratching my head as to what that noise could be. Almost sounds too rapid to be a big end bearing. But the fact that it's not there when it's cold is a little unsettling. I've also read on lots of RB forums guys think the sound is coming from the head, which this one does, and it ends up being a big end bearing. Any ideas?

Funny how I bagged the living shit out of this engine all summer last year and the first few hard pulls this year she gives me problems.

Edited by ST240
GTScotT Grand Master

GTScotT

Posted
Posted

Funny how I bagged the living shit out of this engine all summer last year and the first few hard pulls this year she gives me problems.

Thats a common thing to me, lots of cases i know where a motor has been dormant for a while and then restarted without fresh oil and its given way. I think the old oil dries up and causes things to seize (like lifters) or oil starve to things like rod bearings.

I havent heard the vid yet as im at work, thus cant comment on that im sorry.

AngryRB Grand Master

AngryRB

Posted
Posted

get a piece of pipe and put your ear to it and test where the noise is,

could it possibly be a worn bearing in one of the pullies? i have this noise on a falcon ute but its constant , pretty sure its a bearing noise from worn pully.

kitto Mentor

kitto

Posted
Posted

Yeah, sounds like one of the rod bearings has just started to spin, but it doesn't sound overly bad.

I'd pull the motor out, rip the sump off, inspect all the bearings and crank. You never know you might get away with just replacing the shells if you havn't scored the crank.

ST240 Enthusiast

ST240

Posted
  • Author
Posted

Pulled it apart tonight. I immediately knew what happened when the bearings were clamped on the journals.

SDC11370.JPG

Nothing a ballpeen can't straighten out.

SDC11371.JPG

Hey guys, it's ok if my bearing shells look like bacon, right?

SDC11372.JPG

At least the journals look ok.

Yep. She starved of oil :(. I think I remember the corner that did it in actually, a sharp U-turn at about 7k. Lucky it was on the street and not a track where I may not have noticed it. I also forgot to overfill the sump. f**k! Damn RBs and their starvation issues. A few more hard pulls and it might have been a different story.

This is how THREE of the six big ends looked lol. But at least the journals look half decent and can be reground. But in the spirit of this build I may even gamble and just polish them up, new shells, and slapper back together. Experienced guys, what do you think?

  • 5 weeks later...
ST240 Enthusiast

ST240

Posted
  • Author
Posted

Ok so I rebuilt this thing. And the exact same timeframe, its f**king knocking again.

What the hell could be starving my bottom end of oil so consistantly? Am I missing something!? I've only driven it hard a few times and I've kept the revs down. Theres also 6L in the sump.

What the hell could be causing this???

R33-RB26DETT Proficient

R33-RB26DETT

Posted
Posted

when you rebuilt it did you add an oil restrictor to the head?

Also did you add an external oil head to sump drain?

Both of these mods will help to ensure that oil isn't kept just in the head and that your bottom end isn't starved.

Rolls Grand Master

Rolls

Posted
Posted (edited)

Did you personally build it yourself or get someone to do it? Did you measure all of your clearances or did you just slap it together?

100% it is oil starvation? same bearings gone as before? could there be a blockage?

Edited by Rolls
ST240 Enthusiast

ST240

Posted
  • Author
Posted (edited)

I have the rear feed blocked and the front restricted down to 1.5 mm. No head drain though... I didn't even have the restrictors before I swapped heads.

Yes I did build it myself. And I did check the clearances. They all within, barely, but still in spec. I've built this engine before and I raced it two seasons with the RB25DE head without an issue. I didnt change anything on the bottom end and I it somehow died right after I put the RB26 head and new manifold on it. The reason I think it's starvation is almost all the big ends were cooked to varying degrees, and the mains were starting to go too. But maybe it isn't starvation.

Someone on another forum is suggesting if the crank isn't straight it can do this. Surely it would have to be knocking quite badly to wreck the bearings this fast?? I do have one of those special bosch sensors that I can listen with, but I havent recently. I'm only running 16* at 8.3:1. I maybe have driven 100 km on it, and had only a handful of hard single gear pulls.

Edited by ST240

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • TurboTapin
      boost source Size Garrett gt28 gen2

      By TurboTapin · Posted

      You just need to remove the compressor housing, not the entire turbo. I would not be drilling and tapping anything with the housing still on anyways. 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      So, I put my boat on a boat. First of all, I'm going to come out and say it. Why is Tasmania not considered a holy goal, an apex that all road-legal modified cars go to, to experience? This place is an absolute wonderland of titanic proportions. If people are already getting club runs for once in a lifetime 30 person cruises to Tassy then I've never seemed to see it. It is like someone replaced the entire place with an idyllic wonderland for cars, and all of the people living there with paid actors who are kind, humble, and friendly. Dear god. After doing a lap of almost all of the place I've found that it's a great way to find out all of the little things that the car isn't doing quite right and a great way to figure it all out. All in all, I drove for 4 hours a day for a week and nothing broke. I didn't even need to open the engine bay. This is by all means a great success, but it has left me with a list of things to potentially address. I also now have a 3D printed wheel fitment tool which annoyingly hasn't got any threads in it to actually assemble it. I might be able to tape it together to check the sizing I actually want to use, but it'll likely involving pulling the shocks out to properly measure travel at least at the front, and probably raise the car while I'm at it, at least in the rear. I scraped on quite a few things and I'm not sure how else to go about it. I was taking anything with a bump at what felt like 89 degree angles. And address those 10 other tasks. And wash the car. God damn it is dirty. And somehow, the weather was perfect the entire time - And because I was on the top of Mt Wellington it turns out it was very much about to freeze up there. I did something I typically never do and took some photos up there in what must have been -10 and the foggy felt like suspended ice, rather than mere fog. If you own a car in Australia, you owe it to yourself to do it.
    • QB6SAGR
      Battle of the broken skylines

      By QB6SAGR · Posted

      Damn that was hilarious, and a bit embarrassing for skylines in general 😂 vintage car life ey. That R33 really stomped. Pretty entertaining stuff
    • cosline
      R32 gtr transmission strength, billet plate

      By cosline · Posted

      Hi, I have a r32 gtr transmission. Does any of you guys have an idea how much power it will hold with the billet center plate and stock gearset? At what power level and use did yours brake with or without billet plate? Thanks, Oystein Lovik
    • Rezz
      Spotted on the street....

      By Rezz · Posted

      Saw this replica police car based on a Mitsubishi Starion XX parked next to a 'police box' (it's literally a box) in Hirohata, Himeji City in Hyogo prefecture the other day. It's owned by Morii-san who is a local Mitsubishi Starion enthusiast. According to a local radio station blog post, he always wanted to make a police car himself based on ones he saw in his favourite Manga comics.  As it's illegal to modify a car to look like a police car and drive on the road, Morii-san tried many times to get permission from Aboshi police station headquarters nearby. They refused initially by after they got tired of that they granted him permission. However, the car can only be displayed on private property and obviously can't be registered as long as the police livery is present. The car was completed at a cost of 1.5 million yen (US$ 10,000) in addition to the car cost. A location was chosen outside Hirohata Police box where the car can easily been seen from the street. Morii-san has two other Starion road cars, both widebody GSR-VRs.
×
×
  • Create New...