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Join Date: Jul 2001
Location: Hamden, CT, USA
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It happened on a downshift at Watkins glen going into the bus stop. I think the cause was the crank was repaired. I had it ground and that must have introduced an initiation point for the crack.
Tim
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Tim Lynn 84 911 Carrera PCA E Stock #278 |
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06-16-2004, 05:50 AM
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I don't understand what I'm looking at in that picture since I've never been inside an engine. Someone want to describe it?
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06-16-2004, 07:22 AM
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BTW:
"I'm quite sure I have the same noise you describe. Comes on around 2000 rpm and fades away after 3000-3200 rpm. Sounds like spinning gear chatter, as you described" I have the same noise. Comes and goes. For long, I thought it was my chain, and actually put new tensioners in it. I STILL here it from time to time. It sounds like a grinding/spinning something at moderate RPMS (like 2000-3000) and it comes and it goes. In fact, it still sounds like the chains. My oil pressure blows chunks. It never gets above 3, and it's at zero when the car is 2000 rpms. It's always a few integers behind the RPM value (5,000 rpms = 2.5 to 3 oil pressure measure). Been like this for years.
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06-16-2004, 07:28 AM
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Kurt
Does the sound change with engine load or just rpm. That is a picture of the flywheel end of the crankshaft. The crack starts at the #6 rod journal and goes into the main bearing journal. Tim
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Tim Lynn 84 911 Carrera PCA E Stock #278 |
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06-16-2004, 08:09 AM
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No, I hear it at low idle. Maybe it is the chains dragging on the ramps or something?
Okay, so how does the flywheel mount to that thing? Sorry, i've never seen a flywheel either  I know it bolts on...that's about it.
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06-16-2004, 08:21 AM
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Location: Southern California
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Quote:
Well, after 30 hours, the crankshaft let go in three pieces.  Yes, I was flying (1500' over Redondo Beach). Fortunately, training paid off and I was able to do a safe emergency landing.The moral to the story: I will NEVER use a repaired/ground crankshaft in any vehicle I own...in the air or on the ground!
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06-16-2004, 09:14 AM
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Tim
Did you ever get the crank magnafluxed before or after the grind? How much total grind? Lot of undersized crankshafts out there in use that don't fail. At least you tore it down before it had a chance to destroy the whole engine. Smart move on your part. A great lesson for all to remember. Thanks
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Clifton Brown https://www.mancalamarketing.com |
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06-16-2004, 01:38 PM
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Before the repair I had it magnafluxed and checked for straightness. The shop that repaired it also magnafluxed it. The crank was ground then hard chromed and ground to standard. Something in this process compromised the integrity of the crank, I think.?
Tim
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Tim Lynn 84 911 Carrera PCA E Stock #278 |
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06-17-2004, 05:18 AM
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