Broken crank, what needs to be checked

[cgevan]

This isn't just a basic maintenance question, but I've forgotten my old (2-3 years ago) login info so I've made a new username and I'm limited as to where I can post.

-Short block (fully balanced): 6 bolt 4g63, 2.3 stroker 4g64 OE crank, eagle rods, wiseco 8.8:1 stroker pistons with HD pin upgrade, King race bearings, fluid dampner, BSE, L19 head studs, metal hg, Fidanza flywheel, and new OE oil pump.

-Problem: Crank broken at #4 main (cracked down the counter weight)

-Question: What all needs to be checked and inspected?

I have the trans/t-case/flywheel/clutch out of the car, just enough to physically wobble the end of the crank. Dropped the pan to confirm, but stopped there once the damage was discovered. This weekend I'll problem pull the engine.

I assume:
-check line bore
-new crank
-new main bearings
-new clutch/flywheel (due to slipping/balance)

Anything else?

Thanks in advance for any and all help,
Evan

 

[ckrell]

Looks like you got it covered, are you buying a 100mm eagle crank or OE again?

 

[cgevan]

Looks like you got it covered, are you buying a 100mm eagle crank or OE again?

Not too sure yet. I've contemplated the Eagle option, but haven't done any research to be honest. The previous owner/friends with the original builder suggested an OE, but I've had enough experience with OE to at least entertain an Eagle unit, .

This outcome flashed before my eyes when I got the trans out of the way, now I'm worried the block/rods are trashed.

 

[Alex7747]

What did you do to break the crank?? That sucks.
I read that the oem crank is good for over 600hp(2.4) i know you have 2.3 but i just wanted to throw that out there. But they cost close to ,or just as much, as the eagle 100mm crank.

 

[bastarddsm]

Yeah take lots of pictures. I wonder if this was a tensile failure or a fatigue failure from harmonics. I run a fluidamper to and it kinda scares me.

 

[cgevan]

What did you do to break the crank?? That sucks.
I read that the oem crank is good for over 600hp(2.4) i know you have 2.3 but i just wanted to throw that out there. But they cost close to ,or just as much, as the eagle 100mm crank.

I'm guessing the flywheel wasn't balanced with the rest of it. I read through another thread about broken crankshafts in 2.3s, and it seems the Fidanzas may be the cause... I'm not sure. The car definitely wasn't overpowering the crank, as it's only running 18 psi on a 3076r.

Yeah take lots of pictures. I wonder if this was a tensile failure or a fatigue failure from harmonics. I run a fluidamper to and it kinda scares me.

I will get some pics up asap.

 

[crazytsiawd]

What did you do to break the crank?? That sucks.
I read that the oem crank is good for over 600hp(2.4) i know you have 2.3 but i just wanted to throw that out there. But they cost close to ,or just as much, as the eagle 100mm crank.

oem crank is good for more then 600, shep was still using his oem crank when he was running 8s.

 

[Calan]

shep was still using his oem crank when he was running 8s.

I believe I heard him say that the crank was about the only stock part that he HASN'T broken at some point.

Don't know about the 4G64 in a stroker though. I went with the Eagle crank for mine.