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Flat foot shift

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Hi guys this is probably one for andre but here goes

have we ever punched a hole in a wiseco 1400hd piston in a 4g63 block I’m struggling to find why the failure has occurred car has been used in time attack very reliable last 3 years at 630hp and 600ftlb logs looked fine all be it the event day was hot for us 52 degree intake temps but again no issues last summer I can only aim at fatigue or at the min looking at the sheer aggression of the flat foot shift using fuel cut in closed loop with barrel position sensor and xshift sequential box what do we think other 3 pistons no signs of det fueling at the time was .770 no knock logged fuel pressure on target oil pressure and temps ok I did see a Video of the car on track and it seems very clear from exhaust then a flat shift pop smoke pit lane 😭😭😭😭😭😭 what do we think is it common for a piston to just fail thanks guys

Do you have any picture of the failed parts?

Do you run individual cylinder EGT?

Nothing wrong with valvetrain components for that cylinder?

Did you test the injectors after tearing it down?

Individual temps are not monitored I haven’t pulled it apart yet just inspection with camera

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My thought is that it has something to do with fuel injector spray pattern...

Will test injectors after I throw a set of pistons in there I was more concerned with cylinder pressures and re introduction of ignition after the flat shift

Is the hole on the intake side?

It looks like the piston crown has failed, possibly from overheating and resultant weakening of the alloy. If the injectors check out OK, I'd suspect a blocked oil jet if you use under-piston cooling.

When you pull the pistons, have a good look at the undersides for discolouration and/or carbon/burned oil residue.

The hole and crack run right through the centre line of the piston left to right directly under the plug

That's what I thought, and why I suggested that possible cause.

With the head off, you'll be able to have a good look at any other damage that may not be seen from the borescope.

Rather than wait, this would be a good time to send the injectors off for checking and cleaning - make sure you ask for a check first, so you know if that may have been a contributiong issue, or not.

I have an injector cleaner and will do flow and pattern tests before and after

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