chipped piston can still function correctly?

[danyosun]

So I am rebuilding my 7M GTE and I took my engine to the machine shop to get some stuff done, but while I was assembling my engine together I notice one of pistons was chipped at the end, I was wondering if this is a serious matter? and should i actually replace the piston instead or just go with it? Thanks

here are some up close picture of how it looks

 

[jdub]

Looks like it was dropped. No way I'd use that piston.

 

[IJ.]

I'd be more concerned at the condition of the deck surface.

 

[4U2QUIK]

do not use that piston, the chip will create a hot spot and then you'll have even bigger problems to deal with.

btw, it looks like the piston was dropped.

 

[jdub]

I'd be more concerned at the condition of the deck surface.

Yeah, looks like some corrosion spots...I'd have it machined.

 

[IJ.]

Strange shape to be impact damage.

 

[jdub]

You can see a bit of a bulge on top, but the impact area itself is kinda dark.

 

[IJ.]

Just being a bit concave made me question it but if it hit something that wasn't flat that would explain it.

Either way it's a failure waiting to happen alone with the dragged behind a car on concrete deck surface

 

[danyosun]

see the things is I just had it resurfaced, its really smooth but I dont know what those spots are, the surface is good and smooth, the spots shouldnt make a difference should it?

So from the responses, Imma just replace the piston, right?

 

[jdub]

For a MHG, that is way too rough a deck surface. I would replace the piston.

 

[IJ.]

see the things is I just had it resurfaced, its really smooth but I dont know what those spots are, the surface is good and smooth, the spots shouldnt make a difference should it?

So from the responses, Imma just replace the piston, right?

 

[Mk3runner]

Now that's smooth

 

[jimi87-t]

I don't see how that was just resurfaced....with a belt sander maybe?
I would not use that piston either.

 

[enjoi.this]

That deck is deff way too rough, looks like a belt sander job for sure.
+1 on piston with that chip should be replaced, could even have fractures from the impact since being cast.

 

[4U2QUIK]

Geeze guys it's not belt sander work, but it's definately not acceptable. It looks like whoever did it either had a bad insert, or crap jammed in the seat of the insert. ( very ametureish) On top of the the dark areas appear to be spots that didn't completely cleanup.
F fo fail.

 

[grimreaper]

i was thinking dremel, but belt sander works too.


lucky you, stock pistons are cheap

 

[Doward]

That won't hold a MHG for long.

And no way in hell do you use that piston.

 

[danyosun]

So im just going to pick up a new piston because it looks way too scary to use it
but the things is, the surface doesnt look smooth, but it feels really smooth and that it cant get no smoother than that, i just dont know why there are stains and stuff. should it even matter how it looks? or just the how the surface really feels?

 

[IJ.]

So im just going to pick up a new piston because it looks way too scary to use it
but the things is, the surface doesnt look smooth, but it feels really smooth and that it cant get no smoother than that, i just dont know why there are stains and stuff. should it even matter how it looks? or just the how the surface really feels?

Of course it can get smoother didn't you look at the pic of my engine? :nono:

Chances are run like it is it will fail if you crank the boost up.

The dark marks are errosion lows and as long as they're not under the actual gasket should be fine.

 

[Nick M]

Nice pitting. Those holes look beyond .002". So after the machine shop fixes it, you will beyond specs. That is where the thicker MHG comes in. Actually, you need a machined straight edge with a .002" feeler gauge to check the depth. But they look deeper than 2.

I would still be leary of pulling that much deck material. It makes it easier to warp later. Which is why Toyota says to discard the block at .002" warpage. Yes, I know others have done it and run a MHG with studs tightened well beyond 58 lb/ft..