Ok broken crank poll

[Cornfed4G64]

I also broke one on a g4cs block. It was in the same spot as the pics that were last posted. Maybe 30k on build?

 

[Boosted98gsx]

So if you are running a 2.3L motor, you're guaranteed to break the OEM crank eventually?

Guaranteed? Nothing is guaranteed. High probability? Yes. Especially if you do not supplement an aftermarket damper.

A good rule of thumb, have the crank magnafluxed before any machine work is done on it to verify that it isn't cracked.

It's not whether the crack is there already or not, it's the geometry of the crank and the rod journal on #4 that causes it to crack based on harmonics and stress (stress concentration).

 

[Cesarlcase]

Just curious, but are the effects more likely to occur on a manual or auto or are both equal?

 

[WES_393]

Just curious, but are the effects more likely to occur on a manual or auto or are both equal?

Transmission type doesn't matter. It all has to do with the crank design.


Out of curiosity, how many people who use stock 100mm cranks actually use the weighted/balanced 4g64 harmonic balancer? Could it be possible that slapping a 2.0 balancer on a 2.4 crank can cause issues?

 

[red1993gsallmt]

Transmission type doesn't matter. It all has to do with the crank design.


Out of curiosity, how many people who use stock 100mm cranks actually use the weighted/balanced 4g64 harmonic balancer? Could it be possible that slapping a 2.0 balancer on a 2.4 crank can cause issues?

Looked into this when I first built my motor, I was told they are the same part #. Let me know if you found out somthing different.