baezi z06

iTrader: (2)

hi

why does this happen










Can this be honed and can pistons be used again....

this are very fine scratches not deep, you can not feel any marks at all whith fingers.....

This is a 3-4K miles motor

thanks Baezi

nysbadmk8

4in stroker crank?

If so.. Its a bit on the normal side. Normally that happens, but also hammering on it before the engine has come up to temp can also accelerate this kind of wear.

Piston rock a BDC is a bitch.

baezi z06

iTrader: (2)

yes 4inch crank

can this be honed and pistons used again????

i spun a rod bearing and had a crack in my crank.



and this happened 2 months before


after knock...

whatīs the best way to do, buy a new Crank and put it back together

or throw all this away and re-bore the block

iīm using this as a NA 500rwhp motor and plans are for 150-200 shots of NOS

thanks

baezi

nysbadmk8

What caused the knock event, was the tune off that bad?

Crank is trash, are these 4.005 pistons?

If you cant fingernail the walls I would clean the walls up very slightly, and reuse the pistons.

Are these coated pistons too? The wear on the sides looks a bit on the harsh side for 4000 miles, but they arent in front of me so it could be the photo is just making it look worse then it is.

If I where in your shoes, I would purchase a new rotating assembly... But you could re-use the rods/piston combo if your on a budget.

baezi z06

iTrader: (2)

The tune was way off at that time yes.....

and the pistons are 4.005inch yes, and piston that the photos are off is the worst one, the others are better, and some much much better.

can this have something to do whith type of oil used

the motor *shortblock* was bought new in spring 2009 and it costed well over $6000 at that time and only used not more then 4k miles
then off course i wouldn't like to buy new rotating assembly now ,
but then again i'm not ready to put the motor back together and have some problems whith it right after i break it in.....

i definently need new Crank, one new ROD, and all bearings...

BUT the question is, Can i hone the block, use the used pistons/rods whith new rings..
and will the motor be the same



thanks
Baezi

racer7088

Your top rings have the moly blown clean off so massive detonation was occurring on this deal and the pistons got hot and got big because of that as well. You might be able to just hone it or might not depending on true condition of block. The scratches are from the debris going through the engine but are no big deal. You'd just have to see if it's fixable but it probably is.

nysbadmk8

Clean up the block... get new pistons/rings... and a new tuner...

baezi z06

iTrader: (2)

Was that pistons and rings or pistons-rings

thanks for your help



Baezi

nysbadmk8

Dragon slayer is a great crank... compustar is great too.

I would get new pistons, and a good set of hellfire or steel top rings.

Lt1Porsche

iTrader: (6)

Do you run nitrous at all? Looks like a lean nitrous motor. Or just a WAY WAY WAY off tune.

baezi z06

iTrader: (2)

no nitrous have been used on this motor.....



Would no one use these pistons again....


nr. 8 is missing on the pic., but it lookes the best nearly no scratch

I would much like to hear more coments on this here....

some say pistons can be used again, but offcourse better to buy new ones.

but i don't wante to buy new for $700-800 if i really don't need to

thanks

Baezi

racer7088

No one can really tell you anything without seeing pistons first hand. The skirts have the coatings worn off but again this could be from overheating and from the bottom of the cylinder not being deburred at all.

baezi z06

iTrader: (2)

if i looke at the pistons it seems they are not worn deep,


and they are worn diffirently...


by the looke at it and feeling it it doesn't feel deep worn only just enough to rub the coat off....

here is the worst one



passengers side > nr. 2 and 6 are worst
nr.4 and 8 are nearly like new, no scratch to talk about

driversside nr. 1 3 5 7 are all the same , just a little rubb in the middle
as you can see on the pic here


so does this give you guys better view...

thanks for all your help

Baezi

racer7088

They are "probably" reusable like I said initially but just hard to tell from pictures alone. All rings should freely move with no lifted or crushed ring lands. You at a minimum will need new rings and maybe a touch up hone job.

baezi z06

iTrader: (2)

thanks
for you comments...

all rings move freely as they are now

can this happen in after a bit lean WOTS for example

thanks

Baezi

racer7088

I don't know about any of that but it might have been lean or might be a bit high in compression or might have had too much timing or might not have had good gas at that point. Don't really know.

baezi z06

iTrader: (2)

ok thanks

i'll try to figure this out.


Baezi

baezi z06

iTrader: (2)

here is the block after she was honed....








was hoping for better results....

Baezi

racer7088

Yes aluminum LS1 blocks are not the greatest but those pistons might have gotten pretty hot and big when the rest of that stuff was going on.

mattinokc

Looks like all junk to me I wouldnt reuse those pistons unless its a drag car! finding a machine shop that knows how to work on ls1 blocks out by me is pretty hard good luck to you! that thing has to be smoking blue going down the road