Thirsty Piston
#25
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I don't know about the piston wall clearance honestly. I never had any piston slap, so I doubt that was the issue. Maybe, but I doubt it. There is another guy locally who has the exact same setup with the machine work done by the same shop. He had someone else assemble it though. He's never had any issues with piston slap or anything either. At this point I don't know what I'm going to do. We'll see what they say, but worst case scenario I found a decent 60k 94 motor that I'll drop in.
#26
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Well.. I pulled the block out today. As I was unbolting the clutch, the motor suddenly decided it would turn again. In it's sudden turn, the thirsty piston popped out of the block to the point where the first ring was above the deck, allowing me to pull the piston out. Here's what I found.
![Name: DSC_0520.jpg
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![Name: DSC_0522.jpg
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Not pretty at all. So I get to looking closer. There is one circlip in place, but the other is no where to be found. Not surprising given the damage. I hope I never find it down in the block, meaning it was never there. But I did find some more interesting clues.
![Name: DSC_0525.jpg
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Those grooves are parallel and exactly the same width as the wrist pin, even though wrist pin is now centered, it had to have come loose at some point. These wrist pins are floating right?
![Name: DSC_0530.jpg
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Then some more grooves, I'm assuming the one that ultimately resulted in the hole in the sleeve.
![Name: DSC_0527.jpg
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Size: 33.8 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193889d1501229544-thirsty-piston-dsc_0527.jpg)
I also found this... I dont' know what it is or if it's supposed to be there. The little wire looking thingy above the crank. They aren't present in the honda blocks I've rebuilt, and I never saw the inside of this one.
![Name: DSC_0520.jpg
Views: 57
Size: 47.3 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193885d1501229544-thirsty-piston-dsc_0520.jpg)
![Name: DSC_0522.jpg
Views: 49
Size: 47.6 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193886d1501229544-thirsty-piston-dsc_0522.jpg)
Not pretty at all. So I get to looking closer. There is one circlip in place, but the other is no where to be found. Not surprising given the damage. I hope I never find it down in the block, meaning it was never there. But I did find some more interesting clues.
![Name: DSC_0525.jpg
Views: 61
Size: 50.8 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193887d1501229544-thirsty-piston-dsc_0525.jpg)
Those grooves are parallel and exactly the same width as the wrist pin, even though wrist pin is now centered, it had to have come loose at some point. These wrist pins are floating right?
![Name: DSC_0530.jpg
Views: 76
Size: 51.0 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193888d1501229544-thirsty-piston-dsc_0530.jpg)
Then some more grooves, I'm assuming the one that ultimately resulted in the hole in the sleeve.
![Name: DSC_0527.jpg
Views: 48
Size: 33.8 KB](https://www.miataturbo.net/attachments/general-miata-chat-9/193889d1501229544-thirsty-piston-dsc_0527.jpg)
I also found this... I dont' know what it is or if it's supposed to be there. The little wire looking thingy above the crank. They aren't present in the honda blocks I've rebuilt, and I never saw the inside of this one.
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I'm hoping the pin walked as well. I honestly have no clue if the head was perfect when I put it back on there. There weren't any glaring signs but I also didn't inspect it with a magnifying glass or anything. Upon closer inspection though, it's not quite as bad looking as the pictures portray. It was dirty in the pics and some of that is from droplets of coolant and oil. There aren't any pits on any of the other cylinders and none on any of the pistons. So if there was some detonation I'm guessing it happened in the last moments of it's life.
#34
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Nope.. you're rods are still 100%. Even the one that ran into the block and managed to carve a couple notches out of the iron aren't even scathed. I'll have some more pictures of it when we tear the bottom end off and I can get to the bottom of the cylinders but it really is quite amazing. Taking it back to the machine shop on Thursday when I'm out of class for fall break.
#36
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Regarding H beam rod failiure:
FWIW I googled around for a while and found this really good tech-heavy thread:
http://speedtalk.com/forum/viewtopic...56d1ce84caea98
With this pic:![](http://i344.photobucket.com/albums/p342/Zaran-122/DSC00996.jpg)
H beam rods do indeed apparently fail. From the thread, not from the HP that our motors see though. Also, FWIW I am running M-Tuned rods as well. That came out of a motor that had heavy detonation, nothing piston shattering, but melted **** pistons. The rods were just fine.
FWIW I googled around for a while and found this really good tech-heavy thread:
http://speedtalk.com/forum/viewtopic...56d1ce84caea98
With this pic:
![](http://i344.photobucket.com/albums/p342/Zaran-122/DSC00996.jpg)
H beam rods do indeed apparently fail. From the thread, not from the HP that our motors see though. Also, FWIW I am running M-Tuned rods as well. That came out of a motor that had heavy detonation, nothing piston shattering, but melted **** pistons. The rods were just fine.
#37
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Oh don't worry, that one rod will be tested thoroughly before going back into a motor. If I have to take it down to the materials sciences lab and bribe a professor or two, I will. But in the end, it all depends what the shop is going to do. A very likely outcome is them saying there is nothing they will do and I drop a stock motor in the car. And ultimately, this could've happened from manufacturing defects, although unlikely. On top of that, a lawyer and court costs would be more expensive than just replacing the broken parts myself.
Ninja edit: That thread on speedtalk is pretty awesome. I don't think I've ever seen so many really smart people argue about car stuff before.
Ninja edit: That thread on speedtalk is pretty awesome. I don't think I've ever seen so many really smart people argue about car stuff before.
Last edited by baron340; 10-03-2010 at 02:07 PM.
#38
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Well... the machinist basically said "you're screwed"... he swears that this failure was caused by manufacturing defects. Claims he's seen it dozens of times in Mahle manufactured pistons. Apparently they put out batches that were improperly heat treated, making the ductility of the 4032 alloy even lower and they crack or outright fail almost immediately. So my new question... has anyone else seen/heard of/experienced any similar failures with supertech stuff? If that was the case, an entire batch should be bad.
Oh yeah.. and does anyone know who exactly makes Supertech's pistons?
Oh yeah.. and does anyone know who exactly makes Supertech's pistons?