dezlfrek

iTrader: (1)

one cylinder, front right.. all others were fine.. 11-1 afr..????

turboventura

Is that oil from a busted ring or bad valve seal/guide?

stevieturbo

It's went lean and melted, likely also causing engine damage.

Whether injector or other problem..somethings fucked.

Compression test ?

And I assume you arent suggesting the clean plug was from the same engine ?

LPA PERFORMANCE

N/A or forced induction??

MUSTANGBRKR02

iTrader: (91)

I am going to assume FI since this is the FI section.

Boo"SS"t

iTrader: (2)

Ouch! Brings back memories....

stock48

iTrader: (17)

Pump 91 and boost??

soundengineer

iTrader: (16)

there are lots of possibilities...
all it takes is the right amount of carbon build up or some oil getting in the cylinder...

check your valve seals and valve guides
how do the rest of the cylinder look?

are you on stock rails? or aftermarket rails??
stock fuel pump? aftermarket pump?, multiple pumps?
if its stock rails, then its possible you just starved the rail out and #1 was starved for fuel...

gotta know more details to help you diagnose....

99z28383

iTrader: (1)

To be that bad, you have internal engine damage. Lots of blow by on that cylinder, do a leak down test.

soundengineer

iTrader: (16)

you can melt straps off and not do damage...but you would have to be pretty lucky....
if you have access to a bore scope, you should take a peek in there and visually inspect and find out just how much work you may or may not have to do...

99z28383

iTrader: (1)

You'd also have to have plenty of constant oil getting on that plug for it to build up like that...

soundengineer

iTrader: (16)

oh... I agree.....
theres likely a big hole in the piston and a bunch of blow by that you can feel if you take off the oil fill cap....


realistically... the OP is going to have to tear it down and see if that is the only damage...
and depending on many many factors... he could possibly get away with one new piston and some new rings for that hole and let it eat again...

or, while you are in there, put in a good set of rods/pistons/rings (if they arent already upgraded)

Boo"SS"t

iTrader: (2)

Looks like that plug also lost the top portion of the porcelain. Might as well pull that motor out, co'z it's time for a rebuild.

dezlfrek

iTrader: (1)

ok well yes this was on my turbo, e85 blow through carb'd nova.. all others plugs looked great.. I am guessing that it went lean from some debris i found in the filter from the fuel hose i use in my truck..
I'm pulling it apart today.. but these were coated diamond pistons and has scat rods already.. hopefully i can get a single piston..
ill get some more pictures up as i pull it apart..

JoeNova

E85 is pretty forgiving. Also notice how clean it burns on the other plugs. That buildup looks like excess oil blow-by. What were your ring gaps? They were either way too small, or way too large.

dezlfrek

iTrader: (1)

well figured it out.. looks like a stock 243 valve couldnt hang.. didnt get the piston.. going to have to do a little honing to get the little bit of scuff out of the wall or just run it..

dmaxvaz

iTrader: (1)

where did that piece from the valve go?

stevieturbo

Some vaporised, and some through the turbine wheel on the turbocharger.

I'd be checking timing, and also pushrod length to ensure sensible lifter pre-load.

dezlfrek

iTrader: (1)

timing has been the same at 20* after 12psi..
push rods have .050 to .060 preload on ls7 lifters.
yes and there are no parts to be found thankfully it didnt lodge in the piston but made its way out..
now to pick a better head for the next go around.. who has a suggestion for a 3.830 bore motor?

stevieturbo

I know the piston looks fine from above, and I know the bore isnt that bad...but there could still be piston/ring damage.

It's a bit of a gamble running it again. It probably is ok...but there is a small chance there is damage you cannot see until the piston is removed.

Plus I'd be checking the turbine wheel of the turbocharger. Again it'll probably be very light damage if any.