Terminator piston damage (pic)

[Grey03Cobra]

Now the thing is....When your pistons went south,Did you have blowby?Did you start oiling plugs?Low compression? driveability issues like a rough idle..
Because the car has none of that.I suspect the dealer just doesnt want to mess with it...but they are being cool enough to not void the car in the main frame.

Nope nothing, only the tick. I still got 14psi, the car still idled and drove normally, just the loud metallic tick. I also blew the end off my #1 sparkplug. I originally thought that was the problem because the tick kind of sounded like a miss. When I swapped all the plugs the sound was still there, so I figured the damage was a little more than I though. Upon tearing down the engine the real damaged was discovered.

 

[9A Pilot]

Nope nothing, only the tick. I still got 14psi, the car still idled and drove normally, just the loud metallic tick. I also blew the end off my #1 sparkplug. I originally thought that was the problem because the tick kind of sounded like a miss. When I swapped all the plugs the sound was still there, so I figured the damage was a little more than I though. Upon tearing down the engine the real damaged was discovered.

Was the 14 psi in reference to the cranking pressure..I mean,did you do a compression test?What plugs were you using at the time?

 

[Grey03Cobra]

Was the 14 psi in reference to the cranking pressure..I mean,did you do a compression test?What plugs were you using at the time?

14 psi was the amount of boost I was pushing. I never bothered with a compression test because when I heard metal on metal (ticking), I knew it needed to be torn down. I was running NGK TR7's

 

[cobra93teal]

my car ran fine too... just was ticking AND FORD DENIED THE WARRANTY WORK... now its up to the dealer to do the right thing...YEA RIGHT!

 

[71stang99]

Not to steal my brother's thunder..He'll likley be posting about this more in depth later...But after speculation about various valve train parts....everything from lifters , rocker arms & valve springs..from what he tells me,the dealer did a compression test & found 3 & 7 low..with # 7 the worst....That's where it ends..The dealer appeared willing to do warranty on a conditional basis...valve train related..they'd handle...Short block damage on the other hand...Well,see the original topic..I'm cofused though...which piston in number 7?...All the racket is coming from the last piston on the passenger side..I thought that was 8..

I just wanted to clarify this post for myself, is this after all the work you guys did here on the car in Vegas?
Thanks

 

[Oh Three Cobra]

I have the same tick from the forward passenger cat. I had the stethoscope all over the car and the tick is in the fricken cat. Not the tick they are talking about.

Sounds like that on mine but its on the driver's side. Its barely audible.I have ot be outside of the car and listen closely. Sounds like an exhaust leak to me.

 

[9A Pilot]

I just wanted to clarify this post for myself, is this after all the work you guys did here on the car in Vegas?
Thanks

Yep..

 

[NHRACobra]

If you can catch me.. than i guess u will beat me...cobras can go 170mph just not for over 10-15seconds..

whne you have 300rwhp ur not going to hurt anything.. go get a superchager and hold 180 on ur bottomr end :fart:

 

[NHRACobra]

That sucks guys. Nothing like ford quality. No problems here though :burnout:

Yah, because you have NO power. :lol:

 

[lemosley01]

evil04Cobra and others - I know you have speculated that different rates of expansion are causing the teflon area portion of the piston to contact the wall and thus scuffing it (if I am understanding correctly).

What if the problem is TOO much cooling, instead of not enough; the cylinder walls being cooled too well and thus not expanding as quickly as the piston?

I do not recall how the cylinder flows through the heads and block so I may be off base. It pretty much enters through the front and exits through the passenger side head, doesn't it? I guess if that's the case, with the #3 and #7 cylinders being most affected, it wouldn't be too much cooling, since those cylinders would run hotter than the front ones (because the coolant has already picked up heat from cylinders 1/2 and 5/6). I guess that means I can throw away the 'too cool' theory.

It's odd that it's not 4 and 8 affected - I would expect both of those to run hotter since the already hot coolant is running through those cylinders last (assuming my cooling flow is correct).

Maybe it's because they are 'buried' between hot chambers. 4 and 8, being at the ends, would maybe cool a little better, and 2 and 6 might cool better because the coolant isn't as hot by the time it reaches those two cylinders. 3 and 7, not being on the end, and being nearly last in line would seem to get heat-soaked sooner and stay that way longer.

Someone needs to figure this out. I would hate to see Ford release another Cobra with these problems and give the brand a black-eye. I don't doubt, however, that they aren't aware of the problem and will presumably build the next motor to avoid these problems, all the while denying warranty work.

 

[robbcwz]

How Much Teflon?

Does anyone know how thick a layer of teflon is on the pistons? And Fords reason for it - long term or just run in?

In digesting "Evils" light reading attachment from a while back, they do discuss applying coatings purely to avoid scuffing during the break-in period and the way it is worded suggests that the coating is only very "temporary". Does anyone know if Ford expected the teflon to be a permenant part of the piston? Just wondering!

 

[Emmerson_Biggins]

In my own research on the subject this week, I have happened across a couple of interesting tid-bits. The stuff we have been calling teflon is actually comprised of a graphite moly-disulfide. I spoke with a design engineer who works for Keith Black/Silvolite he has stated that the friction prohibitive coating on a forged piston (like our application) is dual purpose. It prevents scuffing during start-up when the engine does not have a lot of oil on the skirt, and it prevents scuffing from the piston rocking in the bore until operating temperature is achieved. After warm up, the coating then prevents scuffing due to tight machined tolerances needed to seal the combustion chamber in order to meet stricter and stricter emissions standards. In discussing the scenarios presented by members of this forum and the nature of the damage, he concurred that piston clearance and heat would appear to be the two greatest contributing factors. I am getting a junk block that I can disect to see how coolant flows around the #3 and #7 cylinders. I will keep you posted and take pics.

 

[cobra93teal]

talking to dealer today for a final deal! will updated as soon as i know the details...(hopefully within a few hours)

 

[9A Pilot]

Well..after reading the evidence...The handwriting is on the wall for Flyin.
I suggested he get a second opinion after he got the car back from the dealer.But,after I thought about it more,It seems a bit pointless.Like I said,#7 was 11%,#3 was down 5%..Yeah,Time for JE's.
We 'laid' the groundwork for these mods,too.It may have given a false sense of security.The car has an Apten cooling mod,an aftermarket HE,water wetter,& a 'cooler,more efficient' Whipple...I suppose he really can't complain,The car does make nearly 600 rwhp on 91 octane(17psi)..& it took him three back to back max boost bazai runs before something gave...Ya play,ya pay...Welcome to the hobby.

 

[Grey03Cobra]

Well..after reading the evidence...The handwriting is on the wall for Flyin.
I suggested he get a second opinion after he got the car back from the dealer.But,after I thought about it more,It seems a bit pointless.Like I said,#7 was 11%,#3 was down 5%..Yeah,Time for JE's.
We 'laid' the groundwork for these mods,too.It may have given a false sense of security.The car has an Apten cooling mod,an aftermarket HE,water wetter,& a 'cooler,more efficient' Whipple...I suppose he really can't complain,The car does make nearly 600 rwhp on 91 octane(17psi)..& it took him three back to back max boost bazai runs before something gave...Ya play,ya pay...Welcome to the hobby.

That sucks, but damn, three back to back bonzai runs :nono: I only managed one bonzai run on the stock Eaton when my piston went. I guess all his cooling mods helped for a while, but eventually the heat just built up and became too much.

Since the motor is going to be pulled, and the block bore/honed, talk him into getting a stroker kit:rockon: (because we are all made of money, right :-D ) I'm kind of wishing I had while my engine was out.

 

[sndmn_2000]

i had the same exact problem. Burned through #3 and #7

 

[05 Roush]

Here's another interesting article regarding detonation:

http://www.autospeed.com/cms/A_2289/article.html

I especially like the DIY detonation detector.

We could go round and round about why 3 and 7 are getting cooked first. Would it make any difference if 1 and 6 were cooked first? The important thing is that detonation is removed out of the equation. Plain and simple.

High octane + conservative tune + cool intake air = happy pistons. :thumbsup:

 

[Emmerson_Biggins]

If there were detonation, the crowns would be hammered and ringlands cracked. There is just skirt scuffing, detonation is not now nor has ever been the cause of that.

 

[Emmerson_Biggins]

Another sign that detonation is not to blame are the people that have said their rod bearings looked new upon disassembly. Detonation would have hammered them as well.

 

[ShelbyGuy]

but the piston thrust angle isnt something you can really change, since all the 4.6 rods are the same length. you could move the pin in the piston, but then you possibly end up with the lame 347-ish pin-in-the-oil-ring.

on that note, has anyone experimented with a long rod 4.6? piston dwell is my friend.

how does the teflon coating compare to the dry film lubes eg., G&L?