What happened to my motor?

[BMSE]

I have had mixed opinions on what happened with my latest motor. The posted picture is of pistons no.3 and 4. Basically, temp went to 265, I ended up with a crack in no. 4 and 5 cyl, cyl no. 4 and 5 filled with water and the visible damage to the pistons. The cylinders all listed have scars on the walls and the rod bearings all are mildly pitted. I only had 3 hours on this one, I normally get 25 before a refresh and have run one to 105 hrs before. It's a 383 stoker w 570 hp in a road course truck. Any info would help, just never seen this happen to a piston and want a few more opinions.

Thanks

 

[Flat Broke]

Hydraulic pressure found the softest part of the piston?

 

[obnoxious001]

Guess those are a forged piston. Top ring looks terrible,, 2nd ring shows a bunch of wear for only 3 hours? How long did the engine sit after it broke before it got pulled apart? You run water with no antifreeze? I am trying to figure out why so much rust, even knowing you cracked and had coolant in it. Also trying to sort out if cylinder 5 had water, but cylinder 3 is the one that lifted the top of the piston?

 

[Instigator]

Fuel mixture went lean.

 

[BMSE]

I was told that it leaned out really hard on top end from the builder. Thanks for confirming that...

Yes we run water and water wetter, it was torn down a week after it broke...

 

[RUNNINHOTRACING163.1]

I was told that it leaned out really hard on top end from the builder. Thanks for confirming that...

Yes we run water and water wetter, it was torn down a week after it broke...

water injection or meth inj ?











ROCK ON !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :champagne:
http://www.ebay.com/itm/190649028759
ITS A SKATER NATION !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:drnkfr
http://www.ebay.com/itm/NEW-BOAT-TR..._Accessories_Gear&hash=item3cb4089d56&vxp=mtr

 

[DaveH]

to me that looks like a detonation issue.

to lean? maybe. certainely could have been fuel octane issue. maybe you paid for "the good stuff" but got something watered down.

is this a super charged motor? the detonation could be casued by excessive manifold pressure.........stuck WG on a turbo maybe. is this carb or EFI?

need to know some more detailed info on the motor, about what parts you are running and the installation.

if your builder is right and it went lean, you should have had misfires (backfiring through the intake) that were very noticeable.

 

[racerden]

You weren't too far was adding an eyebrow also. I agree on the pre-ignition/detonation (they are different) comments. Probably not a hard part failure; a tune circumstance, yes.
DV