Well?

 

I think I started crying jeeeez, well good luck on the rebuild

 

Good luck on that rebuild. Something to think about when I start building soon.

 

I'm with TedB, looks like a material/manufacturing flaw.

It didn't even go into the high stress areas on the piston. Very odd.

 

Itune,

No I don't have a wideband, and the car was just tuned at BR when the kelford cams were installed 300 miles before the motor let go. The other pistons are still in the car, I didn't get pics of them. Right now I'm trying to decide whether to build it or sell it, I've talked to BR about getting a built head and block, runs about $6200. I am going to post the car for sale and see if I can get 10K the way it is. We'll see how it goes. I now have a post in the private evo sales trying to sell the car if anyone is interested.

Mike

 

if the car had bucking issue the months before you may want to check your injectors.

 

My main questions: Did you clean the piston crown before taking this pic? What fuel were you using? I don't like the way the piston crown looks....it looks like it went through a really lean condition.

If in fact, you didn't clean the piston crown, i suspect a lean condition, which caused the piston to expand against the cylinder wall from the high cylinder temps. This caused the piston to crack. If all your piston crowns look the same as the one you took the pic of, the engine was running very lean across the board. If only cylinder 4 looks this way, something went wrong with the fueling in that cylinder.

My .02

 

No I didn't clean anything, that's the way it came out of the motor. The other pistons look somewhat similar, but like I said, the car was just tuned less than 300 miles ago. I always run 93 octane, usually BP but sometimes other brands. Maybe it was an injector issue, but the only time I had an issue was at WOT. I do appreciate your input though, thanks.

Mike

 

the piston cracked right through the center of the gas ports. I'm with a piston failure... not anything else.

 

Looks nasty. Time to upgrade to 2.3L

 

The only other possible cause I could see is the ring gap closed up and siezed the piston in the bore.

But typically when that happens, it rips the wrist pin out the bottom of the piston.

 

If it's stressed(over expansion from running too lean), its gonna crack at the path of least resistance(i.e. the gas ports in the skirt)....look at the piston crown and tell me that looks OK. He was obviously running lean in that cylinder. Look at how clean the crown is on the exhaust side. This smells to me.

I mean, it's possible that it was nothing more than a failure of the piston, but i don't think it was un-provoked. That's all i'm saying.

 

To OP

N33d4sp33d is selling his brand new br stage 3 2.0 long block for 5000+shipping. I talked to him he is willing to go to 4500+shipping so you can go that route save lots of cash and get car back on the road. His motor has 0 miles. Just another option for you

 

I threw a rod last year and had these same questions as far as what to do with the car. I decided to go with a built engine. 2.4 + fp black and the work done at AMS. So far its estimated to run me around 6k and thats 95% accurate. Not too bad for a 500+ whp evo.

 

What do you guys think about excessive sidewall loading? If he turned too much RPM I would normally expect a wrist pin or bearing failure, but I would think this could be a result. I can't tell which side of the piston it is that broke, though, that would obviously be a quick way to debunk this theory. In the first picture, You can see a small crack on the top of the wrist pin bore, just below the crown. Whether it was the cause of, or caused by, I can't tell. But it does look like there might've been some pin flex.

It's a long shot, I'm just running this up the pole to see if anyone salutes it.