Jump to content
SAU Community

Recommended Posts

RB25 Forged? ID and Damage

Hey guys, I've spent the last while having a decent look trying to fin my precise questions to save having to post, so sorry if this is a repeat but I doubt it, I couldn't find the answers I needed at least. It's 2 part thing. RB25DET (bulk mods not relevant to the question)

A: Can anyone positively identify these pistons form the photo/markings? I have been advised they are a forged piston but cannot find confirmation.

B: The damage near the edge (actually a pop rivet ended up in the motor, don't ask me how). I'm concerned if it were to be used that it could be a detonation site.

Car made (on the current engine) 333 rwkw at 21 PSI. It's a beast. But the engine has developed a knock and I've found some small metallic fragments, although not many, the oil has been in the car for about 35 laps of QR over 2 weeks and the knock has only just started (literally on the last lap) so while it's not a lot, it's not like it's been there long and if it's just started it would make sense to find just a small amount yeah?. So looking at pulling and a rebuild anyway, but have these pistons here already, if they are forged I'd like to use them, but not if it's going to cost me another build later because of that damage. Any help from experienced gurus is very very welcome.

 

It does get some serious use use per this vid:

 

 

 

 

20170425_124931.mp4

20170425_154231.jpg

20170425_154246.jpg

20170425_154356.jpg

20170425_154449.jpg

20170425_183102.jpg

20170425_183123.jpg

Link to comment
https://www.sau.com.au/forums/topic/470189-rb25-forged-id-and-damage/
Share on other sites

Ok, Thanks guys. The more I looked the more I felt they were not forged. Can anyone confirm my thought about a detonations sight? I assume that piston will need to be binned. Rebuild near certainty, just weigh up up the options now.

I know that's mechanical damage, I was asking if I were to use it it would be a sight where detonation would accord due to the thinner raised area (even if I removed most of it) getting hot. But as they aren't forged I don't think it's worth the risk anyway. If they were forged like I was advised then I would have considered it, pending some feedback.

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

    • I seem to the be only person that is using a Haltech 2500 on an NA motor, I've installed a Bosch DBW throttle body to the OEM intake manifold and am having problems maintaining AFR even with the wideband o2.  It will run extremely rich at idle and up to redline, but under load it will go extremely lean in the 20s and i'm essentially having to rev it over 4k and feather the clutch to get it up to speed.  I've read a few other threads of about the butterfly, it seems removing the vacuum to it is supposed to have it remain open, i've noticed no difference under 4k with the vacuum line to it plugged.  I'm hoping someone here has had luck using the NA manifold with Haltech, and if they happen to have a tune for it.  
    • I don't know any details, but I really wouldn't be surprised if they do it as a LHD only version, at least initially.
    • Thanks for the replies everyone. Definitely a coolant push. Oil catch can is empty and always has been. As the engine is out now I'll be having a good look over things. I do have some detonation on the piston tops from a trigger issue back about 5 years ago. I felt it and shut off then bought a new ecu and changed the trigger. Never been an issue since. It never hurt the power, its made almost 80hp more since that incident but I will pull the bearing caps to take a look. If the bearings are damaged I will do a bottom end refresh. Head is being re conditioned at the moment and the block will be cleaned and checked to ensure it's flat. I'll go with a kameari gasket and see how it ends up. The other thing I'm not super keen on is the cylinder colours. I suspect this is from the inlet manifold. The plan will be to put it back together, retune and then stick a plazmaman billet inlet on it and retune. I'm happy with the power, if it makes a little more, then great, but I would rather just make everything more efficient at this stage.
    • Maybe they'll look to do a bunch of presales to help inject some cash fast for their financial issues...
    • Does it also misfire equally when revving?   Josh is very correct in what you should do. The coilpack harness wiring loom itself is a known problem due to its age and the number of heat cycles it has gone through. Throwing parts at a vehicle to diagnose the issue isn't a smart or good way to do it. Secondly, you may have a bad coil pack, you pop replacements in, they fix that issue, but messing with the harness breaks it, so the issue persists. So now you think "well it wasn't the coil packs" and have to continue chasing your tail, potentially swapping back in your shit coil packs and returning the good ones (yes, I've seen people do this because 'it wasn't the problem' and they want to save money). And suddenly, you've got two issues with the same symptoms...   Diagnose, don't use the spare parts shotgun.
×
×
  • Create New...