Burnt Ring Cylinder #4

[FordTechOne]

The rattle sound you were hearing was most likely detonation. Detonation can be caused by excessive spark advance or poor quality fuel, or in this case the aftermarket supercharger. Detonation results in piston damage, typically by cracking the ring lands. That is why the mechanic found leak down through the crankcase.

When a piston is damaged there will typically be damage to the cylinder wall as well. That necessitates an overbore or engine block replacement.

These engines are on borrowed time when forced induction is added, they were simply never designed for it. Towing a trailer only exacerbates the issue due to the increased load and heat generated. That is most likely what finally did the engine in.

 

[Ellison3]

I would think mechanic's next step is that head off.
That should show what the issue is one way or another.
Diagnose and go from there.
If it is in fact a ring, may as well refresh the bottom end along with whatever needed.
Met another owner a few weeks back at Bronco Takeover on Silver lakes Sand Dunes... he told me about his new 6.6.... would go good with your supercharge

Always easier spending someone else's $$$

Good luck with the fix ! ! !

What he said… I’d take the head off for further inspection/ easy access to the questionable components.

Remember when I had a slight tap that turned into a very loud knock in my Wrangler 4.2l 258ci engine. My guesses were all over the place. That is until I pulled the head, and found a lifter stuck in the lifter valley. Different issue, but you get the point.

 

[BSouders80]

I'm not sure why he's not wanting to pull the head off. He said he ran his camera in the cylinder and piston looks fine.
Should I still push him to pull the head? Ask him to look for any cylinder wall scarring? With the rings not holding compression, will there be any obvious sign that it's fried?

 

[BSouders80]

Can these motors be bored out? Then run some oversized pistons? I'll create a separate thread for details, but to build the bottom end, what all should a guy kind of look at? ARP studs/bolts? Moving it up to a 6.6 from 6.2, what is needed on that? I've got some reading to do for sure.

 

[Canuck714]

I'm not sure why he's not wanting to pull the head off. He said he ran his camera in the cylinder and piston looks fine.
Should I still push him to pull the head? Ask him to look for any cylinder wall scarring? With the rings not holding compression, will there be any obvious sign that it's fried?

Like FT1 said, the rattling (pinging) you heard under load was detonation! Bad fuel, too much load, Roush tune has too much timing in it etc...
The piston might look fine (subjective) actually if it was detonating, it will look clean like it was soda-blasted. All the piston wash will be gone from the top edges of the piston.

If it got hot enough the aluminum piston will melt and the ring will get stuck in the ring land. This will definitely leave a mark on the cylinder wall locating the point where the ring is no longer floating and making a seal with the cylinder.
If you are lucky it may just smear aluminum up the bore and muriatic acid will clean that off. If you are unlucky the ring has left a gouge in the cylinder and will need to be bored out to fix it. You can see all of that with a bore scope, but way easier to see extent of damage with head off.
Yes it can be bored, I don't know if Manley or Ford are making any oversized pistons these days.

If your mechanic doesn't want to pull the head to figure out a repair game plan, Id probably be looking for another opinion.
Like I said earlier, pulling the head will tell you everything you need to know about the damage.
Either way, stop running the engine, its just causing more damage.

 

[BSouders80]

I'm not driving the truck. It's been at the shop for the last 3 weeks and when I noticed the miss, it went directly to the shop. I bought my stage 2 whipple from JDM. I'm running the JDM tune. The first time i heard the noise was pulling a 16 Challenger HC on a trailer up a moderate grade. The 2nd time was pulling an empty 6x10 trailer.

Let's say best case scenario - Cylinder wall is okay, piston is okay, but ring is shot. What is the fix for that?

Worse case, cylinder wall is scarred and ring is shot. That would require boring the motor, and new pistons, IF the pistons can be found.

I was looking at Livernois and MMR this morning. Looks like both have a short block that can be purchased. How would the MMR short block hold up to a boosted motor? I was looking to get around 500 whp out of my truck. Can MMR do a stroker motor?

 

[BSouders80]

I double checked with the mechanic and he said he could see wear on one side of the cylinder wall with his scope.

 

[Vash]

@BSouders80 I think you posted up about a month ago regarding a possible vacuum leak and surging issues. Did you ever do any data logs and have JDM review your fuel trims and knock retard values etc? Also, do you have any idea what your coolant temp was when you started getting detonation? Also, we’re you running 91 or 93 octane and what were the ambient temps?

 

[BSouders80]

JDM told me to investigate for vacuum leak. I never did do any data logs for them. Their suggestion was the gasket or o-rings got displaced when the supercharger was installed.

I had tried to run it in 4 wheel drive after the valve train issue crept up. It would do the same noise in 2wd or 4wd. Some had suggested that my vacuum was low causing the 4 wheel drive to try and lock in.

Ambient temp was hot the first time I heard the noise pulling a trailer. Close to 100F.

Coolant temp wasn’t abnormally high. Warmer than normal pulling the trailer though.

This wasn’t the first time pulling the trailer after SC was installed on my raptor. Half a dozen trips taking my car to the drag strip.

I always run minimum 91 octane fuel. If I can’t find 93 octane, I pour in a can of Deatschwerks octane booster.

 

[Canuck714]

I'm not driving the truck. It's been at the shop for the last 3 weeks and when I noticed the miss, it went directly to the shop. I bought my stage 2 whipple from JDM. I'm running the JDM tune. The first time i heard the noise was pulling a 16 Challenger HC on a trailer up a moderate grade. The 2nd time was pulling an empty 6x10 trailer.

Let's say best case scenario - Cylinder wall is okay, piston is okay, but ring is shot. What is the fix for that?

Worse case, cylinder wall is scarred and ring is shot. That would require boring the motor, and new pistons, IF the pistons can be found.

I was looking at Livernois and MMR this morning. Looks like both have a short block that can be purchased. How would the MMR short block hold up to a boosted motor? I was looking to get around 500 whp out of my truck. Can MMR do a stroker motor?

Generally JDM has their tunes pretty dialed in, but towing under boost can create quite a bit of heat and cylinder pressure. I towed with my supercharged Raptor (JDM tuned) a couple times and never had that happen, but there are so many variables that could potentially be the cause of detonation.

Regarding the piston/ring.. If the ring is toast, generally so is the ring land so I would replace both. Can you file the ring land.. Yes.. But I would replace with a new stock piston if you don't need to bore, they are cheap.... https://www.tascaparts.com/oem-parts/ford-engine-piston-al3z6108j
For a grand you can put Manley Forged pistons in every hole.

If mechanic can see a mark on the back of the wall, you need to tear it down to see if it can be cleaned up and just honed or if you need to bore the cylinder to get the groove out.
Either way, you should yank the engine to pull it apart. If you pull the head and Pan you can do just that piston with the engine in the truck, just have to be super careful you don't ding the crank if you are honing it.

As for short blocks from Livernois or MMR.. I am sure they will hold up just fine to boost just fine as long as you are not greedy.
You should have no issue getting 500whp with a boosted 6.2 with a good 93 octane tune. Mine put down 507 at the tire on 37's..lol