... i was wondering if the points in the picture (circled in yellow) could be a weak point... it is the section of the valve relief where there is less material than the rest of the piston (if that makes any sense)... the reason i ask is because one of the local guys here just burned up 2 je pistons at this exact same spot... thanks...



*edit* - another picture

(( borrowed, whoever's pic this, hope you dont mind, thanks))

 

oh hell yeah thats a weak point. thin metal on the edge of the piston near the ring lands is asking for trouble.

 

i would like that know that myself

 

anyone else?... (art, earl, viren, tony, others)... i'd really like to know... thanks...

 

Looks like a sharp edge in the combustion chamber to me.

When the tune (****?) hits the fan, that is one of the first places that will start heating up. Depending on exactly what happens inside the combustion chamber, that part of the piston could be on the list of what gets slagged.

Out of curiousity, what did the guy's bores look like? Does he need a hone? Approx miles on the engine?

 

i noticed with my Je's i have to have my builder debur them, in that same exact spot , the casting is sharp and has rough edges, he said that could cause detonation i guess and probems down the line , supposedly a known fact for JE pistons .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">supposedly a known fact for JE pistons .</TD></TR></TABLE>

That is right!

 

Seems like every manufacturer of engine parts has a weakness in their product. First everyone was having problems with GE sleeves, then Eagle rods, now poorly design JE pistons? Jeesh, whats next!

 

JE Pistons have always been this way, the people who i know who normally run JE's consider that sharp edge the "wrapping" or "container" on the piston, like unwrapping a candy bar before you eat it, you must de-burr the edges of the JE pistons before you use them....

But if he killed some JE's something went wrong with the tuning and/or he is detonating.

 

thats why everyones on the CP bandwagon right now .
every manufactuer has their flaws once and a while, i got JE and Eagle , im in for trouble lol .

 

i had je's and thats where they burnt up
and thats why i switched to ROSS Pistons

 

as long as you keep an eye out for that when you install them , youll be fine .

 

Can anyone give us an idea of what exactly you have to do when you "de-burr" them? Before and after pics would be great, if possible

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by J. Davis &raquo;</TD></TR><TR><TD CLASS="quote">
Out of curiousity, what did the guy's bores look like? Does he need a hone? Approx miles on the engine?</TD></TR></TABLE>

... stock bore... yes, it needs a new hone... and not sure on the mileage... but it was in less than a month... so it was probably less than 1000 miles...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by itr206 &raquo;</TD></TR><TR><TD CLASS="quote">thats why everyones on the CP bandwagon right now .
</TD></TR></TABLE>

... btw, the pics i posted are actually cp pistons... but the ones that got burned were je...

 

ask 93lscivic, he's doing mine .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">Can anyone give us an idea of what exactly you have to do when you "de-burr" them? Before and after pics would be great, if possible</TD></TR></TABLE>


it's juat a matter of taking a fine sandpaper and smoothing out the edges of the valve reliefs

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paul_Vang &raquo;</TD></TR><TR><TD CLASS="quote">
it's juat a matter of taking a fine sandpaper and smoothing out the edges of the valve reliefs</TD></TR></TABLE>

... what grit sandpaper would you consider as smooth/fine enough?

... also, like servion said... anyone have any pics?... thanks...

 

That's a big advantage to going with a big bore. Most all stock bore aftermarket pistons are very thin there because there physically isn't enough room for big valve reliefs and still have material left on the sides. If you notice, most 83mm and up pistons have more meat in that area. That's always the first area to go when you melt a piston.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by servion &raquo;</TD></TR><TR><TD CLASS="quote">Can anyone give us an idea of what exactly you have to do when you "de-burr" them? Before and after pics would be great, if possible</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">That's a big advantage to going with a big bore. Most all stock bore aftermarket pistons are very thin there because there physically isn't enough room for big valve reliefs and still have material left on the sides. If you notice, most 83mm and up pistons have more meat in that area. That's always the first area to go when you melt a piston.</TD></TR></TABLE>

good info tony...

 

Theese are the areas where therea re sharp edges, and it's best to radius them to help eliminate a potential hot spot. (note: also animated the happy and the sad piston )

Brad

 

love the faces...lol

as for teh sand paper grit...I can't remember, but I used 800 I believe