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Old 02-16-2010, 07:32 PM   #21
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Quote:
Originally Posted by Joe Perez View Post
Either way- the front of that crankshaft needs a pretty thorough inspection at this point.


This is the sort of thread where the OP would save us all a lot of frustration by just posting a damn picture of the front of the engine, or at minimum, a through description of what actually happened...
I'll post a pic of the front of the crankshaft when I get home, but all you will see is busted off bolts in the 4 little holes that hold the damper on.

The keyway and large crank bolt are fine.

Cliff Notes

As I said earlier:

-Boosting in 4th gear @ approx 7k rpm
-CLANK (felt like tranny busted again)
-Motor is shut down asap (millliseconds after noise)
-Pulled head, everything looks good
-Pulled oil pan, found bearing material in spades
-Checked datalog, shows 7000ish rpm then shots to 15807rpm in .1 seconds then to zero (shut motor off)
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Old 02-16-2010, 11:25 PM   #22
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Hell, I'd take everything apart and have it checked my my local shop, and if it checks out have them clean it up for you and I'd throw it back together. I'd be most worried about the head I guess, but with the non interference engines like ours, it really just shuts off and sits there. All the danger is in the rotating assembly, who knows what happened in terms of knock/ping/detonation/etc in those few moments. Like I said, probably fine as long as that dust didn't do any serious damage to any sealing/bearing surfaces.
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Old 02-16-2010, 11:39 PM   #23
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I dunno. I would never be able to drive with confidence with any part of that engine. Maybe that's just me. I've gone through that **** once, never again.
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Old 02-17-2010, 01:49 AM   #24
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I dunno. I would never be able to drive with confidence with any part of that engine. Maybe that's just me. I've gone through that **** once, never again.
Meh, tear it apart get everything checked out, if it all looks good through the boost at it again, not much else I can do.

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Went through the log Again and found another glich
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Old 02-17-2010, 02:33 AM   #25
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I'm still a bit confused about the shavings in the pan. If it never did overrev, having never hit the limiter, what caused these shavings? Where did the crank pulley sheer? The crank itself or just the pulley, and why? Maybe I read over it and didn't catch it.
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Old 02-17-2010, 10:57 AM   #26
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It looks to me like you're hard in the throttle until you felt the spike (might have felt like a miss) and then lifted. The 15k spikes can be caused by electrical system noise, insufficient grounding, or if the wires at the CAS are loose. I do not think they're related to the crank pulley failure, and I don't think that the crank pulley failure caused the spike.
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Old 02-17-2010, 12:33 PM   #27
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Quote:
Originally Posted by NA6C-Guy View Post
I'm still a bit confused about the shavings in the pan.
Might they simply be a side-effect of running the engine at high load / high RPM with no harmonic damper attached? Or perhaps the engine was simply on its way out already when the pulley came off?

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Originally Posted by NA6C-Guy View Post
The crank itself or just the pulley, and why? Maybe I read over it and didn't catch it.
He said that the four small bolts which retain the pulley to the front of the crank sheared, and that the threaded section of them are still in the crankshaft.

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I do not think they're related to the crank pulley failure, and I don't think that the crank pulley failure caused the spike.
Having seen that log, I'm inclined to agree. I've seen that sort of phenomenon before on my own engine. In every instance, it was caused by false triggers on the crank/cam sensor inputs, which is generally indicative of bad wiring, inadequate filtration at the MS inputs, or just a plain ole' shitty CAS.

What clinches it for me is that, as Ben points out, you immediately let off the throttle after every one (my logs show the same instinctive reaction) and after the event, the RPM trace goes back to reality and shows the engine decelerating.

There is no Zebra here. Only several horses.
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Old 02-17-2010, 12:38 PM   #28
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The bearing wear is what I can't figure out.
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Old 02-17-2010, 12:43 PM   #29
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You ran an engine at high load and high RPM with no harmonic damper at all. I'm surprised the crank didn't break in half. Have you disassembled the oil pump yet? Quite possible that the gears in it are no longer in one piece.
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Old 02-17-2010, 01:42 PM   #30
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If the oil pump isn't the problem, I bet that its just the crank getting outta balance after the pulley flew off. When an engine is spinning that fast, and then looses some of its reciprocating mass, the crank can experience some crazy torques/forces. Once a crank starts to eat those bearings, it wont stop until that engine stops.
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Old 02-17-2010, 02:06 PM   #31
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If the oil pump isn't the problem, I bet that its just the crank getting outta balance after the pulley flew off. When an engine is spinning that fast, and then looses some of its reciprocating mass, the crank can experience some crazy torques/forces. Once a crank starts to eat those bearings, it wont stop until that engine stops.

Just pulled the main caps, bearings look fine?????

I'll post a pic, running my fingernail across them I barely feel any grooves

But that material in the oil pan def looks like some sort of soft metal.

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Just got off the phone with buddy hat helped me swap the motor way back when.

When we tried to fit a non mbsp oil pan on the block obviously it didn't clear so at first we tried to heat it and form it out, bad idea. After that I just ground down the wide spots and it fit fine. All these shavings look like chips of aluminum and Im betting that they are from the ******* oil pan. If this much metal came off the bearings there wouldn't be any thing left of them and I'm standing here looking at m old motor bearings vs these and these look fine compared to the old stock 1.8

I'm convinced that material can't be from the bearings, it's def from the oil pan.

Guess I have to tear it all apart anyway though, ****.

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Old 02-17-2010, 03:12 PM   #32
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There is no Zebra here. Only several horses.
How about some ducks?? Maybe a chicken/Duck hybrid?


Those pictures aren't very good, but that doesn't look like my idea of 'normal' wear on a high mileage motor.. Get better quality pics of the bearings and the crank journals?
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Old 02-17-2010, 03:42 PM   #33
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Pull the oil pump.
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Old 02-17-2010, 03:49 PM   #34
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Bearings look scary to me man.
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Old 02-17-2010, 03:57 PM   #35
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I thought it may just be the pics...but I wouldn't really call those "good."
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Old 02-17-2010, 04:10 PM   #36
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Hmmm the bearings in my old stock motor look way worse and have noticeable grooves in them, these are almost totally smooth, if it looks like there is a groove in it there isn't it's the pic.

I'll pull the pump, and crank I guess and report back.

Any one have pics of the bearings they've pulled from a motor makin some kind of power after 20k km?
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Old 02-17-2010, 05:14 PM   #37
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Bearings look scary to me man.
Yeah, those look fucked up. The bearings I pulled out of my trashed motor a couple months ago looked significantly better than that.
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Old 02-17-2010, 05:22 PM   #38
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Maybe it's because the pics are out of focus, but the large number of individual longitudinal scratches in your bearings looks like you have been feeding all of that fine metal debris in your pan into your oiling system. I bet your oil looked like metallic flake paint. I'd question the condition of the oil pump if it has been eating a steady diet of metal particles. I'd also be worried about the cam bearing surfaces of the head since they are aluminum.

Good luck with what you find.
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Old 02-17-2010, 05:26 PM   #39
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Yeah. Them's be a bit fuggly on the bearings. Mine looked like this at 110k miles.

Notice they don't look like they were scratched to **** with a 40 grit sandpaper wheel.

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Old 02-17-2010, 05:40 PM   #40
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The other thing that got me is that you said "soft metal" in the oil pan...which makes me immediately think aluminum, and that you've been feeding bearing material to the head as well.
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