Jump to content
SAU Community

Rb25 Cam Cap Buggered

SYK-200

By SYK-200,
in Engines & Forced Induction

 Share

Recommended Posts

SYK-200 Enthusiast

SYK-200

Posted
Posted

Hello everyone...again! a few months ago i built a rb25, and ever since it was running their was a really high pitch squeal coming from the engine and i had no clue wat it was until yesturday i took off the cam covers and found metal shavings at the first cam cap, so i took it off, and what do i find? the cam cap and camshaft have been worn VERY badly, wat can cause this? no oil getting to it? over tightening the bolts? i didnt install the cams, we sent it to our local machine shop and got the block/head cleaned up, also installed tomei valve springs. ill post up a picture so you can all see how bad it is...

post-74114-0-58401200-1329458772_thumb.jpg

post-74114-0-89122200-1329458800_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/392073-rb25-cam-cap-buggered/
Share on other sites
rob82 Mentor

rob82

Posted
Posted (edited)

From those phots it appears to be Abrasive wear which is probably due to lack of sufficient lubrication. It seams weird that it etched the middle of the cam bearing surface away. My guess is they possibly tunnel bored the cam bore and forgot to debur the oil feed cause both a blockage of the oil passage and significantly higher loading on the middle section of the cam journal. Really hard to tell just from those photos.

Edited by rob82
JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

did they do any machining? was it the original cap from that engine installed on the correct side? if so lack of oil is the only reason for that to happen, but to get that bad it must have been getting no oil whatsoever. what does the oil feed look like?

The Dan Grand Master

The Dan

Posted
Posted

If you put the cap on the wrong side and the top half overlaps the bottom half on the leading side, it will start removing material from the cap as it rotates. The removed material will just stay there, stuck in the middle and continuing to wear the cam away like a big clump of camf*ck

SYK-200 Enthusiast

SYK-200

Posted
  • Author
Posted

at JONNOHR31, i dont exactly know what they machined, my brother got the machining work, the engine was my school project for HSC, i built most of it, brother payed for it all...

at abr33, we first started the engine in around july 2011, and since 16th feb, it probably has only been started ~15 times.

is this at all repairable, or a new head is needed now? definately a new cam is needed lol, on the positive side, at least i found this problem before something worse happened!

abr33 Proficient

abr33

Posted
Posted

Repairable? maybe, get a competent shop to weld your busted journal and tunnel bore it back out.

Or if its easier get a new head, your lucky you didnt break your cam and eat your engine worship.gif

Would be a tricky one to repair

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

    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      I’m here solo don’t have any hands to help so haven’t hit it with a timing light 
    • Dose Pipe Sutututu
      S1 rb25/s14 starting problem

      By Dose Pipe Sutututu · Posted

      When you crank your car, and hit it with a timing light, can you see a steady crank timing?
    • PranK
      My BMW E39 528i touring

      By PranK · Posted

      Oh, forgot to add, A few months ago I was getting mixture codes and the car was using crap loads of fuel. You could smell the unburned fuel in the exhaust, it was crazy strong. Economy was over 17.5 l/100 and usually around 19. I smoked the engine and found a leaky CCV hose which I replaced and then I replaced my two pre cat O2 sensors, I also replaced the MAF. This fixed my mixture codes and improved my exonomy but I'm still 14 - 15 l/100 when pottering about town so something is still amiss. Throttle response is much better and it has more pep but I'd like to know why it's still so thirsty (and I'm hoping that whatever it is gives me a bit more poke).    
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Car is on factory injectors/z32 maf/ q45 throttle body/ z32 ecu with nistune 
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Hello all, currently finishing up a rb25 swap into my s14. Having issues with starting, car has spark (confirmed by pulling a plug and watching it spark), has fuel(confirmed by checking pulse/voltage at injectors all spark plugs are soaked in fuel). Car cranks over and pops into the exhaust with a heavy fuel smell but no attempt to start or run, I have torn the timing cover off and triple confirmed timing, turned the CAS in multiple spots both directions, attempted to start with coolant temp and maf unplugged, checked my fuel lines and made sure they weren’t backwards, checked voltage at cas/injectors/coilpacks, made sure all the grounds in the harness are connected and added a few grounding straps (1 from chassis to block, 1 from chassis to head, and 1 from chassis to igniter chip) I am getting stumped here. As a last ditch effort I made a full grounding harness tonight that’s going to run from the battery and add an extra ground from the battery onto the coil pack harness/igniter chip/ intake manifold/ Wiring specialties harness ground/ and alternator. I’m hoping maybe the grounding harness will fix it here but posting here to see if anyone has any other ideas on what else I can check. My fuel pressure is unknown right gauge will be here tomorrow.  IMG_3206.mov
×
×
  • Create New...