My misfire from byron is a chunked piston

Angus

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So I finally had time today to check the car out since it started misfiring after my last run at byron last weekend. Basically, I chunked a piston. :sad:

I pulled the plugs and they were looking like this:


Then I pulled this one (second cylinder to the firewall, pass. side):


I look into the cylinder with my flashlight and see a chunk missing along the edge of the piston head, plainly showing the piston rings.

Now I don't know what other damages may be in there, but I could see the cylinder wall where the chunk was missing and there wasn't any scoring, thank goodness, but who knows what the head looks like...

I also checked my turbo and it spins very freely and makes no noises so I don't think it got hurt.

Now my first step question is can I just all new plugs in and put everything back together and disconnect that cylinders injector and coil? I need to be able to move the car around the driveway and possibly get it to a nearby shop. I did drive the car home to Geneva from Byron like this... What do you guys think?

Oh and what causes this?? :dunno:
 

The Broken Regal

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oh shit, sorry bud... no smart ass comments from me in here :(

you drove it back from byron like that???

damn man, well at least the season is gonna be over and you can build it stronger for next year!!!!

:ford:

curious as to what AFR and boost you were at
 

BillyBru

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dayyyyummm. what heavykevy said. good luck with repairs.
 

hellraiser319

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Personally, if you need to limp it anywhere, stick a magnet down there and check with a flashlight to make sure there are no chunks floating around. If you disable the coil and injector, it will run like crap, but it will run. I wouldn't personally drive it like that though. if you keep that cylinder live, very low revs and you should be fine, if there is nothing in there, damage has been done unless more piston crunches away.

As for what happened in the first place... idk, only thing i can think of is valve float and it bounced against the piston? bad wrist pin? worn out piston and stress fracture gave way? I guess, at least you found the problem, well part of it. Sucks to hear though... :(
 

Turbocharged400sbc

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toss good used plug in and drive it, leave the inj and ignition chances are you already blew the broken land out, see if you still have the misfire wich might point out bent/nicked valves.

detonation, ring hammer/flutter are your two primary causes of ring land damage to hypereutectic pistons. tis fairly brittle shit
 

greasy

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perfect time for a 4v swap :pedobear:
This. 4V swap + turbo = new fastest TCG vert stang. :jg:
this is why you dont build 2vOHC mustangs.
You guys are flat out misinformed. Just because a Mustang is a 4V does not make it less prone to piston failure. Now if we are talking about an 03-04 Cobra 4V, then there is a difference. There are fast 2V's making 900 RWHP with the same amount of money into them as 4V's.

Why would Angus switch to a 4V? He would have to buy new heads, upper/lower intake, computer, etc.... Take that money and build a solid short block and boost the shit out of it. I think Blackbeard will be shutting some people on this board up in the summer when he is making some serious power with a built 2V.
 

syP

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because for the 19,000 sticker price of the car.. he should have gotten an 03-04 cobra to start with.


ive been around quite a few high-powered 2vs... they almost always fuck up around 380whp-450whp depending on application.

my SHO can handle more :rofl:
 

10sec

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I really think you're seeing something else, 99% of the time the piston chunk would have gotten caught up in the turbo, and the plug isn't smashed. Engines don't nicely close the gap, they SMASH the shit out of it. I think the gap was too small, it got REALLY hot when you ran at Byron, closed itself, and made you think your junk was busted. Put another plug in and go beat on it. :dunno:
 

jason05gt

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because for the 19,000 sticker price of the car.. he should have gotten an 03-04 cobra to start with.


ive been around quite a few high-powered 2vs... they almost always fuck up around 380whp-450whp depending on application.

my SHO can handle more :rofl:
You don't know what your talking about.
 

Mike K

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I really think you're seeing something else, 99% of the time the piston chunk would have gotten caught up in the turbo, and the plug isn't smashed. Engines don't nicely close the gap, they SMASH the shit out of it. I think the gap was too small, it got REALLY hot when you ran at Byron, closed itself, and made you think your junk was busted. Put another plug in and go beat on it. :dunno:
He said he saw a chunk of the piston missing. I've seen both. I've seen plugs that looked like they had been through war and other plugs that just looked like they had been gapped shut. There's no protocol that the plugs follow.

If it's anything like a 3800, pop a plug in it and drive it for another 20,000 miles. :jg:

For moving it around you should be fine just tossing another plug in it.
 

Fish

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You guys are flat out misinformed. Just because a Mustang is a 4V does not make it less prone to piston failure. Now if we are talking about an 03-04 Cobra 4V, then there is a difference. There are fast 2V's making 900 RWHP with the same amount of money into them as 4V's.

Why would Angus switch to a 4V? He would have to buy new heads, upper/lower intake, computer, etc.... Take that money and build a solid short block and boost the shit out of it. I think Blackbeard will be shutting some people on this board up in the summer when he is making some serious power with a built 2V.
I should have been more specific and said termi motor. Would that make me misinformed then? :ford:

Why NOT switch to a 4V? Seriously, besides money, why not?
 

jason05gt

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I should have been more specific and said termi motor. Would that make me misinformed then? :ford:

Why NOT switch to a 4V? Seriously, besides money, why not?
Cost and the fact that you can meet his power goals with his current 2v heads.
 

Fish

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Who is to say the heads are reusable? And I already said cost. :)

IMO, pull the heads and see what you are working with. Then make decision. :dunno:
 

jason05gt

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Who is to say the heads are reusable? And I already said cost. :)

IMO, pull the heads and see what you are working with. Then make decision. :dunno:
The heads will most likely be fine. I've seen 3V's which were a lot worse than this (windowed the block) and the heads were fine.
 

Fish

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Probably, but still better see what you are working with. Easier to make a decision that way.
 

greasy

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because for the 19,000 sticker price of the car.. he should have gotten an 03-04 cobra to start with.


ive been around quite a few high-powered 2vs... they almost always fuck up around 380whp-450whp depending on application.

my SHO can handle more :rofl:
Well it is too late to go out and buy a Cobra now, so the point is moot.

Blakbeard has been running close to 400 RWHP without major issue for over 4 years now on his stock bottom end 2V. With his block being built he should be seeing over 500 RWHP. Angus was at that HP level, but he was making a sick amount of torque.

Angus build your bottom end and boost the shit out of it.
 

ilikemtb999

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Just put another plug in it and drive it. Kid I know has been driving his Sti with cracked ringlands for a long time while his engine is being built.


Do a compression test also. Easy on that car
 

Turbocharged400sbc

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Probably, but still better see what you are working with. Easier to make a decision that way.
:werd:

there wouldnt be a whole lotta difference and he may not want to spend the $ for a 4v...its a turbo car, they do damn well with heads that dont flow gobs of air.

teardown and inspect is the best recourse, the ring land is pretty brittle so it can get shattered pretty easily and the bits leave the chamber relatively unscathed, ive also seen em get pinched in the valve seat and have the valve head snap off the third startup after....

if your planning on havng to drive it around to move it for a while before repair ya might want to do a leakdown test before just popping in the plug and driving it. esp if you plan on reusing the block and other components.

i can tell ya first hand there's nothing worse than telling a guy that his sprayed 396 looks fine, all he needs is a piston, and then calling him 2 hours later and informing him his head is now junk.
 

blakbearddelite

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Sorry to hear about the bad luck. I've been waiting 4+ years for something similar to happen to mine.
 

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