Machinist broke piston

[DeNoZZo]

My machinist just informed me that he broke my NPR piston while trying to press it on to my rod. He said the wrist pin seized and it broke when he tried to remove it. He sent me an email about an hour later saying he found some replacements from california and he already ordered them. Now It's to my understanding that the nippon pistons from ebay shouldn't be messed with. And after looking on ebay that's where all of those are from. From what I have heard they are for the most part knock off pistons. The ones I bought were from dsm graveyard and they seemed pretty legitimate. I don't want some knockoff piston in my motor.

What do you guys think?

Should I be worried about damage to the rod?.... because I am. I had 6 bolt rods from dsm graveyard too. Hopefully he didn't ruin the rod because that would mean I would have to find another core and go through the trouble of shipping it there and all that.

 

[BogusSVO]

this is what your machinst was tryin to do
http://www.dsmtuners.com/forums/art...ss-fit-pistons-balace-rods-6bolt-1g-4g63.html

he did not move fast enough or had trash on the wrist pin or in the small end the rod

I doubt he messed up the rod, but it is common for the pistons to crack/break/shatter when pressing them off.

from what I have read here and come to understand, that NPR pistons are the OE supplier to mitsu

but you may want to reserch that yourself some more.

 

[LiquidX]

IMO he should NOT have ordered anything without your consent first. If you are going with a OE replacement, only NPR or OEM. Some people have success with Topline but for some things, you want better quality.

 

[DeNoZZo]

this is what your machinst was tryin to do
http://www.dsmtuners.com/forums/art...ss-fit-pistons-balace-rods-6bolt-1g-4g63.html

he did not move fast enough or had trash on the wrist pin or in the small end the rod

I doubt he messed up the rod, but it is common for the pistons to crack/break/shatter when pressing them off.

from what I have read here and come to understand, that NPR pistons are the OE supplier to mitsu

but you may want to reserch that yourself some more.

Ok, thanks for the info

From my research the NPR pistons are/were the OE supplier to mitsu. But I have also heard that there is a chinese/tiawan knockoff of the NPR pistons that can easily be had on ebay for dirt cheap. Now my NPR pistons/rings were $189 from dsm graveyard, the NPR ones from ebay are around $70. So I don't know if dsmgraveyard has a huge markup, or the ebay ones are the fakes. As far as I can tell they look the same, but I want to be sure for something like this.

 

[2GRick]

Ok, thanks for the info

From my research the NPR pistons are/were the OE supplier to mitsu. But I have also heard that there is a chinese/tiawan knockoff of the NPR pistons that can easily be had on ebay for dirt cheap. Now my NPR pistons/rings were $189 from dsm graveyard, the NPR ones from ebay are around $70. So I don't know if dsmgraveyard has a huge markup, or the ebay ones are the fakes. As far as I can tell they look the same, but I want to be sure for something like this.

A number of Ebay suppliers are located in CA. and are reputable dealers. CNS Auto parts, uyunira etc. and will be happy to answer any questions. I kind of like the piston too though I have never run them.

 

[DeNoZZo]

A number of Ebay suppliers are located in CA. and are reputable dealers. CNS Auto parts, uyunira etc. and will be happy to answer any questions. I kind of like the piston too though I have never run them.

That makes me feel a lot better. I have read on here a couple of threads where people recommended them and have had positive experiences with the NPR piston. It seems like the ones that don't recommend the piston are the ones who have never used it.

 

[BogusSVO]

is he just replacing the one? or the whole set?
If just the one, he needs to match the weight to the other 3 to keep the engine somewhat in balance

yes piston sets are weight matched by the set, but it is not uncommon to find weight differances of 2g-5g from one set to another set

 

[RamenPride]

The ones I bought were from dsm graveyard and they seemed pretty legitimate.

Should I be worried about damage to the rod?.... because I am. I had 6 bolt rods from dsm graveyard too.

Kind of wondering why you didn't buy NPR pistons already hung on 6-bolt rods since DSMgraveyard sells them that way.

Anyway, I have NPR pistons that I got off of ebay. They seem to be the same ones pictured on other sites with the same part number, and seem to be good quality. If they disintegrate when I finally start it up, then I guess I'll know they were "knockoff's"

 

[dsm-onster]

I'm wondering why you're not having the machinist pay for this. He should be sourcing the piston you want. He broke it.. He should fix it with the right piston. He should have access to ream NPR pistons. There should be no question.

 

[DeNoZZo]

Kind of wondering why you didn't buy NPR pistons already hung on 6-bolt rods since DSMgraveyard sells them that way.

Anyway, I have NPR pistons that I got off of ebay. They seem to be the same ones pictured on other sites with the same part number, and seem to be good quality. If they disintegrate when I finally start it up, then I guess I'll know they were "knockoff's"

I guess I never knew they sold them that way

I'm wondering why you're not having the machinist pay for this. He should be sourcing the piston you want. He broke it.. He should fix it with the right piston. He should have access to ream NPR pistons. There should be no question.

He is paying for this mistake

is he just replacing the one? or the whole set?
If just the one, he needs to match the weight to the other 3 to keep the engine somewhat in balance

yes piston sets are weight matched by the set, but it is not uncommon to find weight differances of 2g-5g from one set to another set

I believe he is replacing the whole set, but I will bring that up to him.

 

[dsm-onster]

All is good in the dsm world