2014 4.3l engine rebuild no pistons

[Nick75scottsdale]

I hope this is the right place to post this. I'm in the middle of trying to get a new gen 2014 (LV3) 4.3l rebuilt. Motor had 318XXX on it and began to misfire. Low compression in cylinder 1. My machine shop guy says he needs .040 over pistons and he can't find any pistons anywhere. I checked rock auto and even called summit and they say nothing available as well. Does anyone know where to find some or a work around for this. I had hoped just like with the old 4.3l you could use 350 pistons and I could use some 5.3l pistons but their bores are pretty significant different sizes. Any help would be appreciated, motors been at the machine shop for 3 months.

[Grumpy Bear]

I've used JE Piston or on occasion ROSS when I need something no one is making. They will make anything. OR...can the block be sleeved? 

[Nick75scottsdale]

I'm sure it could be sleeved but this particular machine shop I went with the guy isn't set up to do sleeves. I actually called Silvolite and they said they offer them but they won't be produced until end of May. I was quoted $6500 for a new engine from chevy but their on back order with no date as to when they would be in stock and LKQ wants $4500 for a used engine with 100k. So I figured a rebuild would be the best route.

[Grumpy Bear]

That is certainly a laundry list of problems. Looks like ya wait. GM hasn't any oversized pistons? 

 

Sperry or Jasper? 

[Nick75scottsdale]

I checked JE and Ross like you suggested and they don't list any pistons for chevy V6s. As far as I could see chevy offered .020 overs but that's it. I haven't looked into Sperry or Jasper.

[Grumpy Bear]

7 hours ago, Nick75scottsdale said:

I checked JE and Ross like you suggested and they don't list any pistons for chevy V6s. As far as I could see chevy offered .020 overs but that's it. I haven't looked into Sperry or Jasper.

 

JE & ROSS will make what you need if you ask.  I had JE make a custom piston for a 1952 Royal Endfield Bullet. Venolia used to do all my custom work until they closed. Don't look, ask. 

 

Is too far gone for 20 over?  I mean, did it need 40's or did you just want more displacement? 

 

 

Edited April 15, 2023 by Grumpy Bear

[newdude]

318k?  Machine shop says it needs .040 over?  Does it really have to be pushed out that far or is the shop you picked not so well versed in the work they do?  

 

What was the exact cause of the low compression?  Bad rings?  

 

I'd be looking at a used engine or new engine at this point still.  

Edited April 15, 2023 by newdude

[Nick75scottsdale]

He said the cylinders had .032 thousandths of taper so he would need to do .040 over to clean the cylinder up. That's what I've been told atleast.

[Nick75scottsdale]

The reason I went with this shop is because the other 4 i called said they wouldn't even touch it because they knew parts are hard to get right now for the new gen 4.3 and this guy already had a machined crank sitting at his shop for this engine.

[Silverado4x4]

How about this.CHEVROLET VEGE Remanufactured Engines DCW4 VEGE Remanufactured Long Block Crate Engines | Summit Racing 

[CamGTP]

If the engine made it that far while being .032 thousandths out, I'd just do a .020 and now it'll only be .012 out, should get you many many more years.

 

The amount of LS engines that I've seen people just dingle ball hone with new rings and then go on to make gobs of power is hard to count. And surely those engines had questionable measurements lol.

[Grumpy Bear]

21 hours ago, newdude said:

318k?  Machine shop says it needs .040 over?  Does it really have to be pushed out that far or is the shop you picked not so well versed in the work they do?  

 

What was the exact cause of the low compression?  Bad rings?  

 

I'd be looking at a used engine or new engine at this point still.  

 

Is it true that GM discourages honing/glaze breaking during warranty piston replacement? Even up to 150K on the 2.4? No mention in 19-NA-036 for the 4.3 and either V8. Are they Nikasil lined? 

[Nick75scottsdale]

21 hours ago, Silverado4x4 said:

How about this.CHEVROLET VEGE Remanufactured Engines DCW4 VEGE Remanufactured Long Block Crate Engines | Summit Racing 

Thanks for the input, that's the old style 4.3 though. They make more than enough parts for that one.

[Nick75scottsdale]

21 hours ago, CamGTP said:

If the engine made it that far while being .032 thousandths out, I'd just do a .020 and now it'll only be .012 out, should get you many many more years.

 

The amount of LS engines that I've seen people just dingle ball hone with new rings and then go on to make gobs of power is hard to count. And surely those engines had questionable measurements lol.

The machine shop had actually suggested that themselves but said he couldn't stand behind how long it would last if we went that route.

[Nick75scottsdale]

3 hours ago, Grumpy Bear said:

 

Is it true that GM discourages honing/glaze breaking during warranty piston replacement? Even up to 150K on the 2.4? No mention in 19-NA-036 for the 4.3 and either V8. Are they Nikasil lined? 

From what I've read on this forum, the 5.3 and 4.3 seem to have different liners.