I need to know the answer to this. My buddy dropped off his block for sleeving and assembly. His pistons were used from a previous build and when he picked up his block the pistons were sand blasted. The machine shop told him that he did that cause the pistons had some carbon build up on them. Is this ok???

 

They should never sand blast the pistons!! They shoulda used a soft wire brush, cleaner and patience to to get the carbon off. Depending what kind of sand they used it will make the pistons very course and rough. Meaning it will create alot of hot spots on the pistons. What you need to do is sand them down using high grit and get them as smooth as you can....

Why do you think pistons come with a smooth mirror finish on top...

 

Should have soaked them in carb cleaner or ATF.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">Why do you think pistons come with a smooth mirror finish on top...</TD></TR></TABLE>

This was why I was concerned. I will post pics of them!

 

that shop owes your buddy some new pistons

 

I assume you really mean glass beaded.Properly done it's not damaging to the pistons.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJIN BUILDR &raquo;</TD></TR><TR><TD CLASS="quote">I assume you really mean glass beaded.Properly done it's not damaging to the pistons.</TD></TR></TABLE> WHat assures that a good job has been done????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iBrandon &raquo;</TD></TR><TR><TD CLASS="quote">Why do you think pistons come with a smooth mirror finish on top...</TD></TR></TABLE>

because they are "pretty" that way and they sell better LOL

the pistons will work just fine as long as they didnt standblast the sideskirts and everything. ive seen plenty of beadblasted piston tops. i actually did the tops on one of my motors a few years back just to see how it worked out. it ran perfectly.

 

so what if the pistons have some carbon on them? when i reuse pistons, i just clean em up as best as possible then drop em in, they are gonna get dirty again anyways..

 

I don't see anything wrong with blasting the tops

 

tony how do you feel about the way the fuel puddles on the top of a "untouched" piston vs. how it kind of spreads across the piston evenly on a piston thats been modified such as a blasted piston. think it makes any kind of a difference in a running motor, or does the carbon build up over time sort of do the same thing?

 

Umm, i don't think you should have liquid fuel puddling anywhere in the cylinder. The fuel should be atomized before it even gets in the cylinder.

 

just put 2 layers of duct tape on the skirts, aint gonna hurt the pistons.

 

haha yea well puddles will be bad obviously, not sure if it somehow may have any other effects or not...guess not lol

 

Kewl I thought it would be bad! I dont know if the shirts were blasted you can't really see. Good **** then! Thanks