All 8 pistons cracked? What happened?

08Stroke · Nov 22, 2017

So I’d like to get some opinions on what the heck happened here. Less than 45k miles on motor #2 and boom! Cracked number 8 clean across and the other 7 have smaller fracture cracks in them. I’m at a loss. These were fly cut, delipped and coated Mahle pistons. The cracks are all right at the lip of the fly cuts on each piston. The truck was dyno’d at 630whp and is stock fuel and air. No where near a big power truck. Is it just a coincidence that 2 weeks prior new tuning was downloaded to the truck? What’s everyone’s thoughts on this? Also, I’m considering going with the maxxforce pistons this go around. Is that the best option available right now? Who’s got the best pricing? Thanks in advance for any input.

PrecisionEngine · Nov 22, 2017

Got any pictures? I don't have an answer for you, but some pictures might help others determine what happened.

sootie · Nov 22, 2017

crap tuning that sprayed right on the edge of the bowl, with a ton of timing. its like a cutting torch. Get Gear head tunes and i bet you will be fine with hd pistons. At least i was. You wont make 630 i doubt but 575-590 is good enough for stock fuel and air. I can just imagine how hot it was.

No its not a "big power truck" but you are pushing it too hard. Get a larger atmosphere charger and make more power than what you have, a lot cooler and cleaner. would be cheaper than replacing engines lol

CATDiezel · Nov 22, 2017

Flycut and delipped pistons can be problematic if they are incorrectly milled. The leading edges can create stress risers and in turn reduce the ability to handle higher levels of heat.

This is odd being you were also ceramic coated.

Unless you looking for BIG power, I would not flycut reliefs for valves... my personal opinion.

Just curious. Who's tunes did you have prior too and who tunes recently installed?

08Stroke · Nov 22, 2017

sootie said:
crap tuning that sprayed right on the edge of the bowl, with a ton of timing. its like a cutting torch. Get Gear head tunes and i bet you will be fine with hd pistons. At least i was. You wont make 630 i doubt but 575-590 is good enough for stock fuel and air. I can just imagine how hot it was.

No its not a "big power truck" but you are pushing it too hard. Get a larger atmosphere charger and make more power than what you have, a lot cooler and cleaner. would be cheaper than replacing engines lol

I’ve tried GH tuning and wasn’t pleased with the trans tuning at all. I’ve spoken with my current tuner and he told me it was running 18* timing max.

It actually made 630 on other tuning. It probably made more power on this particular tune, that info was just included as reference that the truck isn’t making huge power numbers.

I’d rather not get into dropping names at this point of who did what. It starts to sound bad and look like I’m trying to talk **** about the companies. I’m not easy on my truck and I’m well aware of that, but I’d like info on how to better prevent this issue again. Whether it be better pistons and/or different tuning.

sootie · Nov 22, 2017

tuning. and add air

08Stroke · Nov 22, 2017

It’s getting turbos this go around. I’m leaning towards Rudy’s 72/59 setup.

co04cobra · Nov 22, 2017

I agree with sootie on the probable cause.

If you do turbos I have this set for sale also.

http://powerstrokearmy.com/forums/showthread.php?t=79805

purplepstroke · Nov 23, 2017

Another thing is how long were your full throttle runs. Did you go from 0-120 pr anything where egts stay up for a long time.

Jomax · Nov 23, 2017

purplepstroke said:
Another thing is how long were your full throttle runs. Did you go from 0-120 pr anything where egts stay up for a long time.

Pistons are that fragile in the 6.4s? I’ve gone to max speed on my 6.7 countless times hitting 1800 egts etc..

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Sportchassis06 · Nov 23, 2017

Jomax said:
Pistons are that fragile in the 6.4s? I’ve gone to max speed on my 6.7 countless times hitting 1800 egts etc..

Sent from my iPhone using Tapatalk

They are Flycut and Delipped pistons.......

sootie · Nov 23, 2017

Sportchassis06 said:
They are Flycut and Delipped pistons.......

And??? That would make them more reliable not less...

6.4 Stroker · Nov 23, 2017

This isn't the first case of flycut, delipped pistons I’ve herd of cracking.

Sportchassis06 · Nov 23, 2017

sootie said:
And??? That would make them more reliable not less...

Wheres the PROOF???It's EASY to be a KEYBOARD ENGINEER

sootie · Nov 23, 2017

Sportchassis06 said:
Wheres the PROOF???It's EASY to be a KEYBOARD ENGINEER

eat a dik. Your douchery calmed down for a bit but know its flaring up again it seems...shouldnt you be getting drunk and gorging on turkey right now??

Unlike you, I actually work on my own truck, and many others, and have seen many failures/not failures first hand.

Have you ever built a six four? Or blown up a six four with different pistons in it?

Sportchassis06 · Nov 23, 2017

sootie said:
eat a dik. Your douchery calmed down for a bit but know its flaring up again it seems...shouldnt you be getting drunk and gorging on turkey right now??

Unlike you, I actually work on my own truck, and many others, and have seen many failures/not failures first hand.

Have you ever built a six four? Or blown up a six four with different pistons in it?

Practice what you preach.MISERABLE PRICK

sootie · Nov 23, 2017

Sportchassis06 said:
Practice what you preach.MISERABLE PRICK

LOL LOL that's all you could come up with?

Sportchassis06 · Nov 23, 2017

sootie said:
LOL LOL that's all you could come up with?

No,thats all you are worth.

sootie · Nov 23, 2017

Sportchassis06 said:
No,thats all you are worth.

Now you know my net worth? Interesting...

lincolnlocker · Nov 23, 2017

Sportchassis06 said:
Wheres the PROOF???It's EASY to be a KEYBOARD ENGINEER

this isnt awol.. leave these types of chit posts out of these kinds of threads. you constantly start chit and need to go elsewhere to do so.

sootie said:
eat a dik. Your douchery calmed down for a bit but know its flaring up again it seems...shouldnt you be getting drunk and gorging on turkey right now??

Unlike you, I actually work on my own truck, and many others, and have seen many failures/not failures first hand.

Have you ever built a six four? Or blown up a six four with different pistons in it?

you two need to get a room!

live life full throttle