what causes this? is it a bent or broken rod? did the crank flex? i just want to know cuz ive seen it happen to other people, now it just happend to me! but im building another motor, so i would like to know so i can strengthen that up. lmk p.s i have a hole in the block for people that dont get the title or just want to be a smartass...lmk

 

nothing with your crank..it will lie in the rods or pistons..
1."if boosted"to much pressure to compress and rod will bend then brake
2.water"hydrolock"water can not compress and rod will brake
3.piston failuar"normaly high rom"the piston can not take the stress and it cracks on the bottom forcing the wrist pin to pull out then rod slaps around
4.rod bolt failuar.at high rpms the rod force is i think matched at8K like 48Klbs and 9k 80klbs.well during downstroke at high rpms your bolt cant handle the stress and pulls apart like a twizzler and the rod comes loose and could do it5

thats about it i would say..as long as you have your crank polished b4 installing new bearings,and use forged parts with arp2000 3/8" bolts you will be safer