How does this keep happening

[robmustang201528]

Misfire code cylinder 8 code again low compression. They pulled the pistion out this time and found a crack in the pistion ring. After picking at the ring it came apart. How does this keep happening? Last time I had cats on the car and I had a misfire code but we never took the pistion out to see the damage. We noticed the cat was clogged and came to the conclusion that the cat got clogged and damaged the pistion so I bought a brand new shortblock, but now I have no cats, brand new short block in for two months and I ran into the same issue. Car still runs good no smoke, no hiccup, no misfire symptoms besides a check engine light. What do you guys think is the problem? Is it tune related.

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[ypena02]

It would help if you included details about what modifications are done to the vehicle.

 

[robmustang201528]

Vortech jt trim v7
8 rib pulley upgrade
Id1000 injectors
JLT intake for vortech kit
VMP boost a pump
Beefcake torque booster kit (turbosmart hypergate45 wastegate)
Turbosmart e-boost boost controller

 

[robmustang201528]

Also had my injectors tested. They passed. No issues

 

[drive_55_not]

I'd say it's from detonation, Did you clean the piston or was it that clean when you took it out? What does the plug look like, any oil in the intake around #8 runner?

Could aslo have a cracked intake runner ..

 

[Dusten]

Likely, a tune issue. To much timing. To lean.

A rungland issue is almost always heat from something. Being cyl 8 points to that even more.

 

[ypena02]

Who tuned it? First guess would be too much timing.

 

[robmustang201528]

Only running 10.5 lbs of boost. Yeah he cleaned off the pistion. He said there was no sign of detonation.

 

[Dusten]

Only running 10.5 lbs of boost. Yeah he cleaned off the pistion. He said there was no sign of detonation.

A) your failed engine killed your cats
B) not much kills ringlands besides detonation

 

[Velgen]

We had the same issue with our car. Heat is one of the number 1 causes of ring and failure. Do E85, it will help with detonation and heat.

 

[robmustang201528]

So you guys think it tune related right? Machanic said it was a defect from Ford.

 

[ypena02]

Who tuned it?

 

[mustang1]

was the new short block a standard short block ? a previous posting said that the standard N/A ring gap can be too tight.

 

[Tommy V]

U need to run e85,much cooler charge and will not detonate.Just because it was only 11 psi of boost does not mean u had no knock,how much timing,e85 does alot better with higher timing.

 

[robmustang201528]

Stock short block lund tune

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