L84 can I save it ?

Fredo1888 · February 23, 2023

My l84 5.3 cracked some pistons now thinking of doing a light hone but wanted to know if it would even save the engine ? The scratches are pretty light my nail doesn’t get stuck but I do feel em. The pours on the other hand I’m not sure what could have caused those little things ?

Edited February 23, 2023 by Fredo1888

swathdiver · February 23, 2023

Crummy fuel cause that? Deposits that landed on top of the piston maybe? Or was it just not finished correctly while being machined?

Fredo1888 · February 23, 2023

@swathdiverNot sure I had it on dyno pushing it and the boost cracked two pistons. They were still together and didn’t really shatter couldn’t even tell they were cracked until I pulled them out. Those little pours is what really has my thinking why they are there. Doesn’t have any rust

Edited February 23, 2023 by Fredo1888

CamGTP · February 23, 2023

I've seen way worse engines still working just fine.

Seems like you got the pistons really hot and they expanded a little bit too much, likely where the marks came from. Probably why they cracked.

The marks are above the top piston ring so on the new set of piston they won't do anything to them. I'd slap it back together and be a little more careful.

Fredo1888 · February 23, 2023

@CamGTP yeah sounds about right I was thinking I should hone the block for new chromo rings and forged pistons ? Going with gpi. Should I hone the walls ?

CamGTP · February 23, 2023

A quick hone job would never hurt.

Gangly · February 23, 2023

Crosshatch actually doesn't look bad and as mentioned above, the scrapes are above the top ring for the most part. I would re-hone the cylinders, new rings, new pistons, and be a little more conservative with the tune next time. Then again, since the motor is out and the short block is being worked on, I might would stroke it or punch it out a bit since its going to get machined any ways and your replacing the pistons regardless.