Need help diagnosing my broken cylinder walls. 3.0 16V
01-20-2014, 01:36 PM
#46
Burning Brakes
Join Date: Apr 2009
Location: Westchester NY
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Sorry for what happened.
At this point the engine builder and the tuner should be looking at what they can offer you, since it's my understanding that you had this engine put together and tuned by them. I really don't know the story behind this build but from what you stated they are responsible for the build.
Good luck
At this point the engine builder and the tuner should be looking at what they can offer you, since it's my understanding that you had this engine put together and tuned by them. I really don't know the story behind this build but from what you stated they are responsible for the build.
Good luck
01-20-2014, 09:52 PM
#47
... Looks like you were running pig rich but you can see the pitting from the knocking, or is that just dirt? Looks like its time to sleeve your block and get new pistons, oh and find a new tuner... Sorry man
01-21-2014, 08:41 AM
#49
Anyone got a sleeved 3.0 block for sale? Sleeved with deck plat would be perfect. Can ship my block as a core change.
Short block with 16V Turbo pistons is also of interest.
Short block with 16V Turbo pistons is also of interest.
01-21-2014, 08:51 AM
#50
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A couple of random thoughts / comments –
If the builder followed the Wossner recommendations then I that could not be a problem – I have used quite a few Wossners without any problems.
The damage is on the thrust sides of the cylinder walls. These are a sides on the pistons that see the most side loading due to connecting rod angles – usually the first areas to show damage.
Detonation can easily break piston rings…but breaking all four is really uncommon. Usually the performance will drop off a lot when one ring breaks that people turn the engine off.
Detonation can cause head lift – detonation is usually accompanied by very high cylinder pressures.
What ECU are you running? Trigger system? Were the dyno guys tuning from scratch?
This is a good example of the need for the ‘one throat to choke’ project - if you can find a shop that will build and tune the engine than you don’t have to worry about the ‘he said, she said’ crap that I bet you are going to hear. Its almost impossible to prove cause (with 100% accuracy) when there is this much damage. Even if you do the builder can come back with comments like ‘they should have stopped before completely trashing the engine’ comments. Sorry you are stuck with this, I don’t know the shops involved but I bet you are going to have a hard time getting anything from them.
I will look on my shelves to see if there is anything I have that might help. I know I have some JE 16v pistons for 106mm, they would have to be used in a sleeved block.
If the builder followed the Wossner recommendations then I that could not be a problem – I have used quite a few Wossners without any problems.
The damage is on the thrust sides of the cylinder walls. These are a sides on the pistons that see the most side loading due to connecting rod angles – usually the first areas to show damage.
Detonation can easily break piston rings…but breaking all four is really uncommon. Usually the performance will drop off a lot when one ring breaks that people turn the engine off.
Detonation can cause head lift – detonation is usually accompanied by very high cylinder pressures.
What ECU are you running? Trigger system? Were the dyno guys tuning from scratch?
This is a good example of the need for the ‘one throat to choke’ project - if you can find a shop that will build and tune the engine than you don’t have to worry about the ‘he said, she said’ crap that I bet you are going to hear. Its almost impossible to prove cause (with 100% accuracy) when there is this much damage. Even if you do the builder can come back with comments like ‘they should have stopped before completely trashing the engine’ comments. Sorry you are stuck with this, I don’t know the shops involved but I bet you are going to have a hard time getting anything from them.
I will look on my shelves to see if there is anything I have that might help. I know I have some JE 16v pistons for 106mm, they would have to be used in a sleeved block.
01-21-2014, 09:04 AM
#51
A couple of random thoughts / comments –
If the builder followed the Wossner recommendations then I that could not be a problem – I have used quite a few Wossners without any problems.
The damage is on the thrust sides of the cylinder walls. These are a sides on the pistons that see the most side loading due to connecting rod angles – usually the first areas to show damage.
Detonation can easily break piston rings…but breaking all four is really uncommon. Usually the performance will drop off a lot when one ring breaks that people turn the engine off.
Detonation can cause head lift – detonation is usually accompanied by very high cylinder pressures.
What ECU are you running? Trigger system? Were the dyno guys tuning from scratch?
This is a good example of the need for the ‘one throat to choke’ project - if you can find a shop that will build and tune the engine than you don’t have to worry about the ‘he said, she said’ crap that I bet you are going to hear. Its almost impossible to prove cause (with 100% accuracy) when there is this much damage. Even if you do the builder can come back with comments like ‘they should have stopped before completely trashing the engine’ comments. Sorry you are stuck with this, I don’t know the shops involved but I bet you are going to have a hard time getting anything from them.
I will look on my shelves to see if there is anything I have that might help. I know I have some JE 16v pistons for 106mm, they would have to be used in a sleeved block.
If the builder followed the Wossner recommendations then I that could not be a problem – I have used quite a few Wossners without any problems.
The damage is on the thrust sides of the cylinder walls. These are a sides on the pistons that see the most side loading due to connecting rod angles – usually the first areas to show damage.
Detonation can easily break piston rings…but breaking all four is really uncommon. Usually the performance will drop off a lot when one ring breaks that people turn the engine off.
Detonation can cause head lift – detonation is usually accompanied by very high cylinder pressures.
What ECU are you running? Trigger system? Were the dyno guys tuning from scratch?
This is a good example of the need for the ‘one throat to choke’ project - if you can find a shop that will build and tune the engine than you don’t have to worry about the ‘he said, she said’ crap that I bet you are going to hear. Its almost impossible to prove cause (with 100% accuracy) when there is this much damage. Even if you do the builder can come back with comments like ‘they should have stopped before completely trashing the engine’ comments. Sorry you are stuck with this, I don’t know the shops involved but I bet you are going to have a hard time getting anything from them.
I will look on my shelves to see if there is anything I have that might help. I know I have some JE 16v pistons for 106mm, they would have to be used in a sleeved block.
.
The guy doing the mapping where arranged and recommended by the engine builder, and I also paid the engine builder to be present during the mapping. The engine will be sent to a well know and respected engine builder who will go though the engine and check all measurements. One or two of the cylinders has slightly less damage, so hopefully they should give the necessary answers.
Running Link G4 Storm with the 951 trigger on the flywheel.
On the positive side, it made 380whp @ 1 bar, with the cylinders looking like that.
Last edited by KSira; 01-21-2014 at 09:20 AM.
01-21-2014, 09:35 AM
#52
Rennlist Member
Thanks, much appreciated
.
The guy doing the mapping where arranged and recommended by the engine builder, and I also paid the engine builder to be present during the mapping. The engine will be sent to a well know and respected engine builder who will go though the engine and check all measurements. One or two of the cylinders has slightly less damage, so hopefully they should give the necessary answers.
Running Link G4 Storm with the 951 trigger on the flywheel.
On the positive side, it made 380whp @ 1 bar, with the cylinders looking like that.
.
The guy doing the mapping where arranged and recommended by the engine builder, and I also paid the engine builder to be present during the mapping. The engine will be sent to a well know and respected engine builder who will go though the engine and check all measurements. One or two of the cylinders has slightly less damage, so hopefully they should give the necessary answers.
Running Link G4 Storm with the 951 trigger on the flywheel.
On the positive side, it made 380whp @ 1 bar, with the cylinders looking like that.
01-21-2014, 10:07 AM
#53
My Vi-PEC uses the same software as the Link G4, it uses the stock flywheel sensor on the ring gear for speed reference and never returned any kind of trigger error.
The arming threshold is the only table I can see that may cause trigger errors if not set correctly.
The arming threshold is the only table I can see that may cause trigger errors if not set correctly.
01-21-2014, 10:56 AM
#54
Rennlist Member
yea it seems like i was the only one having that trig error issue. I was literally on the phone with many ppl from the around the world. haha. The only variable i was able to find is that i am not using the stock fly wheel. Everyone and i mean everyone was using a stock flywheel.
01-21-2014, 10:59 AM
#55
Nordschleife Master
The cylinders does not look like they have been bored or honed so I would start with double check the pistons specs so they are indeed correct for your block.
01-21-2014, 12:24 PM
#56
Rennlist Member
I think Chris White's comments are the most pertinent. Listen to everyone, but pay attention to the expert(s).
A few more comments:
- You paid the engine builder to be there. What was his role? I would imagine it was to monitor the tuning and protect his work. Given that, I'd say even without determining the cause, he didn't do his job and he needs to belly up and help with correcting the problem. Does he have machining capabilities? Is he an engine builder or an engine assembler? Unless he has the knowledge, experience, and capability, you would be best served by going elsewhere to have the engine properly prepared. It will minimize your cost in the long run.
- A blown head gasket (tuning issue) can result in bores looking like this. Coolant is a poor lubricant between pistons and cylinders.
- Can you post a photo of the underside of a piston? It can be very telling.
- The whole engine needs to be looked at, measured, and confirmed to be good (as Chris suggested).
- I have a sleeved block, or can properly sleeve yours for you.
Duke - love your car!
A few more comments:
- You paid the engine builder to be there. What was his role? I would imagine it was to monitor the tuning and protect his work. Given that, I'd say even without determining the cause, he didn't do his job and he needs to belly up and help with correcting the problem. Does he have machining capabilities? Is he an engine builder or an engine assembler? Unless he has the knowledge, experience, and capability, you would be best served by going elsewhere to have the engine properly prepared. It will minimize your cost in the long run.
- A blown head gasket (tuning issue) can result in bores looking like this. Coolant is a poor lubricant between pistons and cylinders.
- Can you post a photo of the underside of a piston? It can be very telling.
- The whole engine needs to be looked at, measured, and confirmed to be good (as Chris suggested).
- I have a sleeved block, or can properly sleeve yours for you.
Duke - love your car!
01-21-2014, 11:02 PM
#57
Race Car
Where are you located, I'm guessing Europe by the side marker light? Not directly related, but did you use a break-in oil before putting in the good stuff?
I'm way outside my territory here, but since I haven't seen it a specific mentioned, those scores were almost certainly made by the rings. May have been gapped for an NA application (i.e. tighter), or detonation. But given the location of the scoring in the bore, It seems to have definitely been the rings (as opposed to the skirts). There are probably more Wossner pistons in 944 than all other aftermarket ones combined, but get the batch number off of them when you tear it down, and get that info to Lindsey. They can pass it on to their supplier (who is a BIG 944 guy), and on to Wossner.
I'm way outside my territory here, but since I haven't seen it a specific mentioned, those scores were almost certainly made by the rings. May have been gapped for an NA application (i.e. tighter), or detonation. But given the location of the scoring in the bore, It seems to have definitely been the rings (as opposed to the skirts). There are probably more Wossner pistons in 944 than all other aftermarket ones combined, but get the batch number off of them when you tear it down, and get that info to Lindsey. They can pass it on to their supplier (who is a BIG 944 guy), and on to Wossner.
01-22-2014, 01:25 AM
#58
Chris White, Can I hire David to photograph and document the build I am hoping to have you do for me? That way if I have a problem I can tell the judge that I choked the right guy.🙈
01-22-2014, 05:40 PM
#59
Today i noticed something strange. It is possible to tip the piston back and fort between intake and exhaust side. The gap looks very big. Is it suppose to be this like this?
01-22-2014, 06:06 PM
#60
Addict
Rennlist Member
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Not really.. The gap should look tight and piston should not tilt, but maybe this is due to destroyed rings.
This is why I do everything myself. If I screw it, at least it is my fault.
This is why I do everything myself. If I screw it, at least it is my fault.