Piston broke due to improper installation of wrist pin snap ring, period. If it were a piston metallurgy problem, the piston would have broken both skirts. It broke only one, meaning the wrist pin had to have slid to one side ( the side that broke) and during the downward motion tore the skirt off. Again the snap ring was either not installed, or installed improperly.

You could tell the machine shop this all day long, but the fact is, he has the final word unless you persue this legally.

Which if all else fails, you should

Crap it all... pics later of all the fun chunks in the motor.

I'm not going to pursue it legally, either way it turns out, I will be in a deeper financial hole. I never found the snap ring. I asked him to disassemble and see if he could locate it, but he refused. I guess I'm on the hunt for a decent used motor. Oh.. and M-tuned record is slightly tarnished. The rod is bent. Not in a buckling way, the wrist pin and the big end aren't in plane anymore.

Dude, you don't need to invest much at all to pursue it legally. Filing a claim in small claims court is so easy a caveman could do it. (quoting magma here) Just fucking do it.

Don't let that shop fuck you like that, shit.

Iirc, filing a claim in Texas is like $25. It's pointless not to. You never know, you could scare him into something.

Just looked up your county. 184.50

http://www.knoxcounty.org/circuit/forms_civil.php

Made it easy.

Considering Mahle makes most OEM and aftermarket forged pistons (including the ones used in F1's), I'd venture to say it would be correct if he's seen those fail more then others, but that is a wrist pin retainer. They are hell to get in correctly, and even more of a pain to pull out.

After tearing the motor apart today and not finding that clip, I'm starting to think it may not be there at all. It wasn't in the pan, that's for sure. I now have to thoroughly flush out the water jacket just to be sure it isn't in there anywhere. On top of that, I called M-tuned, 949racing, and supertech. 949 said this is only the 3rd or 4th issue they have ever heard of out of supertech pistons, and this one is the only one that wasn't melted. M-tuned said they had seen one other case with similar damage and marks inside the bore and they came to the same conclusion that it was a missing ring clip. Supertech said they have had no complaints of others breaking out of that batch. After all of that evidence, I'm going to see what he says and possibly pursue court.

Good luck.

I would, realizing your location baron. S&G auto machine in Bristol is baller as hell, does great work for cheap.

This shop generally does too... just the few exceptions I've seen.. but I'll definitely look those guys up.

Well.. apparently the shop owner was in a better mood today. After telling him the ring clip was totally missing and that really nobody else had had any problems with the pistons, the owner beat around the bush and didn't exactly admit he did anything wrong, but he's going to help me out. I'm going to buy the replacement piston after he dye tests the others just to make sure they are ok. He said he should be able to straighten the rod too. He's going to do the labor free and sleeve the block for me. All I should have to shell out for is a single piston and a set of rings. Soo.. that solution works for me. We'll see how it turns out.

Might be a good idea to source a used block, but that seams like a better deal than going to court.

Good to hear :bigtu:

It's possible to straighten a rod?!??!?

--Ian

Huh.

I'd at least give Marc a call and see if they can hook you up with one new rod & pin. Not real sure I'd trust a "straightened" rod, regardless how how good it was before the unpleasantness.

And yeah, blocks are not hard to come by and probably a good idea. I don't think I've ever heard of anyone sleeving a BP engine. Your engine guy does realize that this is a sleeveless iron block, right?

Never heard of straightening a rod. Just get a new one, and a new block too. I am getting ready to build my other one or i would offer it up. Also, Gary at classic investments in blountville tn should be able to take care of you for cheap.

Hell.. I have no idea if any of it's actually possible or not. If he can sleeve it though, I'm not worried about that part at all. It's not surprising that you don't hear about it given the general cheapness of the miata community and the same sentiment that it's easier to replace a block than it is to sleeve one cylinder. But on top of that, how many times have you seen damage to only the water jacket and not all the way through the block? I called Marc, he said 1 rod is $150 + shipping while a whole set is only $330. The pistons aren't quite so ridiculous, they are just a little more than 1/4th the cost of a set. It's not the first time I've heard of straightening a rod, given that they are forged steel. As long as they aren't cracked, it isn't a problem, and that's what the dye tests are for. I'm going to look at the budget a little more closely and see if I can swing a new rod and piston just the same. But in the end, I don't think I can afford everything. It's 1 of 3 options:
1. Sleeve block, straighten rod, replace piston (cheapest)
2. Replace rod and piston, sleeve block. (arguably the safest)
3. Replace rod, new block, stock pistons and risk the cylinders being round enough to just brush it and use new rings. Problem with that is actually finding a decent motor. I found a protege motor locally with 93k on it, but it's a junkyard and no history on it.

I dunno.. maybe I will be able to afford all 3, but I doubt it.