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I've been running 8 psi for a while now, completely stock engine except for the turbo setup of course. After a pull It didn't want to idle right and when cranking the engine it sounded like low compression. So I pulled the head expecting to find a melted piston. I'm guessing it's a broken ring/ringland? A/F ratio never has been lean. Pics attached:
#3 cylinder
#3 cylinder intake runner also has a substantial amount of oil in it while the rest are dry?!?
The oil is from the pcv going in that area. That oil vapor isn't a good thing for your octane in that cylinder, could be the cause of the det.
When you rebuild, use a catch/vent can instead of stock pcv.
The oil is from the pcv going in that area. That oil vapor isn't a good thing for your octane in that cylinder, could be the cause of the det.
When you rebuild, use a catch/vent can instead of stock pcv.
Thanks for the input. Does that cylinder scoring look like ring failure?
The oil is from the pcv going in that area. That oil vapor isn't a good thing for your octane in that cylinder, could be the cause of the det.
When you rebuild, use a catch/vent can instead of stock pcv.
Doesn't look like that at all. Even stock pcv can handle turbocharging at that level.. Not at all a crankcase issue here. This looks like tuning detonation scoring from timing, not afr. Too much heat.. PCV had nothing to do with this..
Doesn't look like that at all. Even stock pcv can handle turbocharging at that level.. Not at all a crankcase issue here. This looks like tuning detonation scoring from timing, not afr. Too much heat.. PCV had nothing to do with this..
So you're saying it had too much timing in it at WOT causing high cylinder temp? Sorry I know very little about tuning. I built the tune from scratch using crome and an ostrich emulator...
The scuffing in that position on the cylinder wall is a common sign of a ring land failure. It doesn't look like it broke persay so much as the ring land area basically melted and deformed.
The scuffing in that position on the cylinder wall is a common sign of a ring land failure. It doesn't look like it broke persay so much as the ring land area basically melted and deformed.
I will be pulling that piston out tomorrow, so I'll put more pics up then. What would have prevented this? Less timing? Or is 8 psi too much for stock b16 to handle daily
I will be pulling that piston out tomorrow, so I'll put more pics up then. What would have prevented this? Less timing? Or is 8 psi too much for stock b16 to handle daily
did it get tuned. was the engine healthy before tuned. sometimes the they just let go
Last edited by ls joker; Nov 15, 2015 at 05:03 AM.
Engine was freshly overhauled just before it got a turbo. I pieced the turbo setup together and tuned it myself as best as I knew how. Afr's were good. 11.8-12.2 at wot. It's got about 3000 miles on the turbo and daily driven. I've done a lot of full throttle pulls, so I wouldn't say I've been easy on it. It ran good for what it was.. stayed beside a lightly modded STI from 40 mph roll
I will be pulling that piston out tomorrow, so I'll put more pics up then. What would have prevented this? Less timing? Or is 8 psi too much for stock b16 to handle daily
Psi is irrelevant when it comes to this. If you want tuning advice, head over to the Engine management forum with any tables, maps, logs that you have, and you may get better consensus. But that's where new tuners like yourself will get more concise answers, not here.
If you killed a ringland at only 8psi on 91 then clearly it wasn't tuned.
Post the details of your entire setup...
Lol I'm saving that picture! The car has 800cc injectors, ostrich, tuned using crome, stock fuel pump, wideband, t3/t4 turbo external wastegate, fmic... that's about it...
I win lol. The rod was actually wedged inside the cylinder and around the crank. Took me the better part of 3 hours to remove it. I have no idea where the rest of the piston went either. The funny thing is the block this happened to is still viable with a patch over an oil galley, didn't even punch through the block.
OP can you post screenshots of your ignition and fuel maps? That will tell the tale the best. While your AFR might have been solid it looks like ignition timing is to blame here.
B16 ringland failure?
