so this dreaded cylinder 8 thing... 2010 mustang gts and up? or only if you do certain mods to them or?

That's extremely scary. Very low mileage on vehicle and how long it was actually supercharged. Scares me to drop the money next month on one. I know the whole gotta pay to play. But eeek.

This is not the regular cylinder #8 issue. This is a different problem. The scope revealed a black piston head, which means it was running rich. If it were blued or discolored that would be a sign of running lean, combine with heat would be a tune issue in my experience. It's definitely a head scratcher right now until we dive into the block.

I would say be aware that you are going to lose your warranty, unless you get an FRPP kit and have ford install it. But you will pay a ton of money, probably what I will pay to buy the kit, put it on, then forge the internals. If you want to boost, do it.

Best course of action, trade in and get a 13+ GT500 lol

Well, gave a call to ProCharger today and ran the details by them. Based on everything, they think it is a freak anomoly too. And they won't be able to help me until they get more information. So basically tear down the engine and see what fully went wrong. They don't believe the SC is the problem, just like I thought too. To me, all signs point to an error in the casting of the piston, which Ford will probably not own up to. ProCharger just wants more details, so it looks like this is going to be all out of pocket.

Anychance it may have been blowby afterall coupled with running rich? That would, to me, explain a little more of the black on the piston, burning oil.

I don't want this to come off bad, but if you have those JLT brake ducts removed, I will gladly buy them to help fund the new motor goodies.

I say go ahead and build it as well. Contact JPC Racing or any of the other big time shops and see what rods and pistons they recommend in their builds.

Haha, I appreciate the willing to help me fund the rebuild by parting out my current car :ROFLJest: I already started prepping the bank account by scouring my house for spare change and selling off all the stock parts that no one wants to buy for scrap metal. Doesn't seem like much, but stock cats go for $35 a piece (leftovers from my 2013 V6) and change goes along way. 1/5th of the way there buy doing that.

If it were a blowby issue, there would be some oil also on the spark plug right? This is just from my research, but I think some Mustangs in the past that had misfires like this due to blowby would have oil on the spark plug preventing detonation. Pictures will come in time once we tear this puppy down. My only thing is I have to work quickly as I will be heading to NTC in California by the end of this week for a month with no phone. So I basically have to work quickly and hope that ProCharger will work with my shop if they are able to help me.

At this point, it is going to be forged rods and pistons as long as nothing else is damage. Upgrade the oil pump to a billet setup and call it a day. With the power levels I plan on running (no more than really what I have now), this setup with the stock crank will be able to and that safely. Most likely will go with an MMR setup as they have the best prices.

Oil blowby, if serious enough, can cause detonation. The presence of oil lowers the octane of the fuel.
In addition, although it is rare, detonation can also be caused by rich conditions in the cylinder. But it is usually more common under lean conditions.

good luck on everything bro

Only way ProCharger is going to warranty anything is if the kit or tune cause the failure. Which I am thinking proving the rich condition caused this is going to be hard. I didn't know that could do so, but I should find out more details by the middle of this week.

Appreciate it. All the other 5.0s in my area that I know I have been keeping in contact with also since I maybe the first to go forged internals. Seems like I am the guinea pig for this experiment.

Make sure to get the Triangle Speed Shop billet gears. Best on the market.

Does FRPP have a forged shortblock for the Coyote 5.0?

I will have to look into them. I was planning on going through MMR for everything, but if there is something that much better out there I will check it out.

That's not good at all

Well, I got the word back today. Turns out my inclinations of a bad casting were substantiated. There were irregular casting marks in the metal of the piston, indicting a weak spot in the piston itself. It was only a matter of time, given the SC & the higher run temps in cylinder #8 accelerated the catastrophic failure. Everything else pertaining to the block were still fine, so right now it's just a replacement piston and rod bearing. That has my wallet feeling much better than having to dish out the dough for a forged setup that is really not needed for the power levels (575 RWHP) that I will be staying at.

For future peace of kind, I will be having the head cooling mod and probably billet oil pump gears while the block is torn apart. After it's all back together we will check the compression to make sure everything is in specs. But it looks like I will be saving about $1500 & will have the car running in about a week after everything comes back in.

Today has been a good day.

Sound like a QC issue with the piston.