Did a bad tune blow my engine?

[armykyle1 [HACKED ACCOUNT]

I don't see a tune causing this.

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[Jay-rod427]

So installing a new ring on a slug I should be worried about it brittleness? Not bending it?
News to me

If the tune effected the failure what do the other holes look like?

If you use a ring installer then you will have zero problems. Put them on by hand depends on what material ring you bought but still chancing it.

Agreed. Rings are more like a spring steel. They are fairly flexible, or else you would never be able to get them installed. I have never snapped a ring during an install or removal. If they were brittle, then I would probably have a bag of them laying around.

I'm doubling down on something was in the combustion chamber or an injector was not seated correctly or fouled.

Do you use above said installer? There ya go.

Now both of you take a stock ring and try to bend it to the degree of pictured ring/piston. It will snap...

With that said aftermarket race rings are more forgiving as they could be gas nitride, or ductile iron upgrades. Production mustang GT without a doubt does not use a quality ring like this from the factory.

 

[SJulian10mm]

I'm doubling down on something was in the combustion chamber or an injector was not seated correctly or fouled.

I'm voting object got in the chamber, which now may be in the pan.

 

[HISSMAN]

If you use a ring installer then you will have zero problems. Put them on by hand depends on what material ring you bought but still chancing it.



Do you use above said installer? There ya go.

Now both of you take a stock ring and try to bend it to the degree of pictured ring/piston. It will snap...

With that said aftermarket race rings are more forgiving as they could be gas nitride, or ductile iron upgrades. Production mustang GT without a doubt does not use a quality ring like this from the factory.

It will not snap when seated in the piston as it has two opposing forces on either side of it. That will cause it to bend exactly like you see in the picture on a broken piston.

 

[HISSMAN]

Watch how brittle this cheap stock ring is off of a VW... Two minute mark.. You get an example of one bending and one breaking. It all depends on the type of steel, and which ring we are talking about as they usually are different materials.

 

[CNCLester]

Watch how brittle this cheap stock ring is off of a VW... Two minute mark.. You get an example of one bending and one breaking. It all depends on the type of steel, and which ring we are talking about as they usually are different materials.

To clarify, iron is brittle period, when compared to more malliable metals such as steel, austinetic stainless steel and red metals like bronze or copper. Iron can be somewhat malliable as different alloys of iron are available. That's why it springs just a bit. Go past it's elastic limit and it will snap or crack. It is able to stand tremendous compressive loads and is very wear resistant. Making it good for piston rings. No way will it bend that much unless very hot. It's gonna be hotter than the piston because of friction with cylinder wall, and aluminum is much more thermodynamically conductive than iron. Meaning it will cool much faster.
Sorry for the metalurgmetal lecture but in this context I thought everyone might have interest.

 

[BmacIL]

So this failure happened at 70 mph on the highway? Not during a pull? You had Kooks headers on w/o a tune? Green cats?

 

[HISSMAN]

To clarify, iron is brittle period, when compared to more malliable metals such as steel, austinetic stainless steel and red metals like bronze or copper. Iron can be somewhat malliable as different alloys of iron are available. That's why it springs just a bit. Go past it's elastic limit and it will snap or crack. It is able to stand tremendous compressive loads and is very wear resistant. Making it good for piston rings. No way will it bend that much unless very hot. It's gonna be hotter than the piston because of friction with cylinder wall, and aluminum is much more thermodynamically conductive than iron. Meaning it will cool much faster.
Sorry for the metalurgmetal lecture but in this context I thought everyone might have interest.

Lecture or not, the top ring will bend just like that when the piston breaks. Not always, but I have held a lot of pistons in my hand that had bent rings, not caused by heat or detonation. As a matter of fact, if I go up to my parents this weekend, I believe that I have a mustang ring that is bent just like pictured in a box. At least I hope it is still there.

 

[Noggles]

Gonna agree that unless the base file was for a completely different setup (e85 or something extremely different) there’s zero chance this was tune related. I’ve back yard mechanic tuned a few cars (all LS based) and had a couple copy and paste mishaps on my personal cars that I quickly rectified. All it did was run very rough even at a 17.0+ afr on pump gas. Fixed the issue and went on. Had injectors go bad in other cars from age and again they just have a miss. You aren’t melting down a cylinder on a basic n/a engine from a down injector. Especially not at part throttle.

This was some sort of install error or some crazy mishap with the base file being totally wrong for your setup but even then the car shouldn’t have ran well enough to get out of your neighborhood let alone your driveway.

 

[Plimmer]

Misfire from valve leakage

• Excessively lean conditions

• Excessively High Cylinder temperatures

Piston Damage

• Pre-ignition

• Excessive levels of detonation


Where did the above comments come from?

The coyote will throw a code and go into limp mode if it is not happy with what is going on.

 

[Jetnoise]

Misfire from valve leakage

• Excessively lean conditions

• Excessively High Cylinder temperatures

Piston Damage

• Pre-ignition

• Excessive levels of detonation


Where did the above comments come from?

The coyote will throw a code and go into limp mode if it is not happy with what is going on.

That's all well & good..... but how does it have anything to do with the cat mishap?
Or does piston damage only occur on detonation or pre ignition???
Ever dropped a valve before? Ever have shot sucked down a cleaned up intake?
Things can go Kabom! before the code even knows the code...
But let's explore the possibilities here....YouTube videos don't count

 

[Jetnoise]

To clarify, iron is brittle period, when compared to more malliable metals such as steel, austinetic stainless steel and red metals like bronze or copper. Iron can be somewhat malliable as different alloys of iron are available. That's why it springs just a bit. Go past it's elastic limit and it will snap or crack. It is able to stand tremendous compressive loads and is very wear resistant. Making it good for piston rings. No way will it bend that much unless very hot. It's gonna be hotter than the piston because of friction with cylinder wall, and aluminum is much more thermodynamically conductive than iron. Meaning it will cool much faster.
Sorry for the metalurgmetal lecture but in this context I thought everyone might have interest.

So you got an A in the periodic table. I got a D
Want to see a top ring, oil ring, scraper bent at 45degrees
I have interest in good info. I have no interest in desktop dyno

That's all well & good..... but how does it have anything to do with the cat mishap?
Or does piston damage only occur on detonation or pre ignition???
Ever dropped a valve before? Ever have shot sucked down a cleaned up intake?
Things can go Kabom! before the code even knows the code...
But let's explore the possibilities here....YouTube videos don't count

 

[SJulian10mm]

What do the intake valves look like for that hole? I'm still voting something got in there. passed the intake valves...sure, I had a small washer get passed the valve of a 2.8 V6 Ford motor in my Pinto Wagon mini derby car. Now in my case it didn't bust the piston, but the point is, it got past the valve. That valve and seat looked like it had chewed on the washer for a while before dropping it into the combustion chamber. All I knew during the derby is that it wasn't running on all 6, but that's fairly common as I have finished derbies just chugging along on 3 or 4 cylinders a few times, usually distributor cap busted or spark plug wires grounded out against something hot which melted the insulation...zoomie headers. All that to say in my case the banged up small washer was right there on the piston when I pulled the heads, but had the piston broken, it may very will have fallen down in the pan. So again I say check the pan.

 

[Austinj427]

If the tune effected the failure what do the other holes look like?

This is a good question.

If the other 7 look good and show no signs of pre-detonation, there is something that is likely not tune related that caused a problem.

I would be cautious about putting those injectors back in a new engine before getting them tested.

 

[aleccolin]

Do you have any more pictures showing exactly where on the piston circumference the crunched area is? The quench pads are 90 degrees from the wristpin centerline, so if some small foreign object got into the combustion chamber it wouldn't have to be larger than maybe 80 or 100 thou to do that. So if it's crunched at the quench pad location that's probably what happened.

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