Like the title says, I am wondering what causes something like this to happen.

 

picture of the wrist pin, c clip?

 

The c clip was in the oil pan and the wrist pin appeared fine, exepct for rounded at the end from working its way out and rubbing against the cylinder wall.

Every single piston is cracked where this one just broke. Only on one side of the piston and on the same side the wrist pins fell out.

 

wow. are those forged? what brand?

 

SRP Piston with eagle rods. It was tuned at 15 psi making 350 whp and 275tq

 

wow......all 4 were the same? How long had they been in that block?
Was your A/F tune good???? thats crazy that all 4 bit the bullet.....

 

WOW....

Its hard to say specifically what caused that kind of carnage. How many miles were on the motor? How was your tune? Stock bore/sleeves? SRP pistons aren't the best but regardless they shouldn't fail as such. How do the top of the pistons look? Any other damage occur besides the obvious?

 

I would look at the rods and see if they were true in every dimension. I would think the pistons werent traveling square to their bores. This is odd.

 

I have SRP pistons. My engine was at 248 whp for 17K miles. I have put on another 19K miles on it N/A. Keep us updated on this.

I know SRP was crap many years ago. Were these pistons from that era? I bought my pistons in August of 2005.

 

did you install the wrist pins small end first and heated up?

sorry bro

 

how much play was there between the piston and the rod while the wrist pin was in there with the clip?

 

The pistons had some miles on them. But I had just recently put them in a new motor. The tune sealed fine. 14s at idle high 11s low 12s in boost. Conservative timing 13-14 up top.

No other obvious damage. I'm bringing to the rods to the machine shop so they can check them out.

Any other ideas?

 

my old eagle/srp setup was a floating wristpin. no press or heat involved.

thats a pretty wierd failure for just 1 piston but for all 4 to fail the same way makes me lean more towards the setup or installation rather than manufacturer defect. Let us know what the machine shop says, Im curious about this now because Ive never seen anything like that


***edit*** those wrist pins did just slide right in, correct??? if they were over sized or too big for the pin hole on the piston and they were pressed in that would cause a similar failure I would think. Whats the engine btw?

 

The wrist pins did slide in easily. They were snug but went in smooth.

It was an ls/vtec with a standard t3/to4e

 

did the motor have the proper thrust clearance? Measure the endplay on the crank. Your honda might have experienced a case of crankwalk... To have all 4 of them cracked or broken on the same side obviously indicates something was 'side loaded' preventing the pistons from riding square in the bore.

 

Wow, in for a conclusion, sorry for the loss man...

 

Well the pistons didn't all break on the same side. All except for one did. Number 2 cylinder was the only one that cracked on the side opposite of the timing belt. I'm not saying it isn't a case of crank walk, that is still a possibility.

Thanks for the input, I haven't gotten around to bring everything to the machine shop yet, I am going to try to do that tomorrow

 

this is kinda what I was thinking.

 

Also by the coloring inside the piston, looks like it was very hot.