Rasim

Happened twice. piston is burn out...
Do you know where i can get used one?
new is to expansive

320 dreamer

robertamg might be able to help you. he just did a major upgrade on his project

430

I suggest before driving off with your "new" piston installed you spend the time to track down the problem.

MBfinatic

Whats done to this C32?..

Rasim

We have very poor quality fuel in our country, and may me i have wrong AFR.
LET TUNE. CODE3 supercharger pulley. crank shaft 178mm pulley SL 55 air intake, stock place KN filters. NEEDSWINGS isolation kit, performance spark plugs.

Rasim

saying it happened twice, i could do 10 000km between/

320 dreamer

right off the bat im seeing that your running stacked pulleys. without upgraded injectors my bet isnt the fuel but the lack of fuel due to the injectors going static

lizardjack

That's want he said. Wrong AFR.
The stacked pulleys gives about the same ratio as 185. You don't need to mess with injectors when you run 185 don' u?
It could be the pump or the filter. You have to check the fuel pressure under full throttle/max rpm.
When check AFR, it also could be a bad tune.

mikekuriger

If you need one piston, chances are you need 8 pistons.

430

C32 - so worst case scenario is 6 pistons.

lizardjack

I blew two pistons at same time. Replace only 2, 20k miles since that - no problem.

Robert AMG

iTrader: (1)

i don't want to sell the pistons until i finish the project and be sure everything run ok, after that i'll see, not before 1-2 months.

is this the same piston that is burned twice, if yes you have a clogged injector, also check the fuel pressure. where do you live? do you make high speed runs four and fifth gear?

lizardjack

He lives in Azerbaijan, the fuel quality is quite an issue there.
And yes, he does hi speed runs. Usually sprints on highways.
Is the hi speed run a problem for C32? I've already seen it twice, the same failure under same condition. Exhaust valve in a 1st cylinder is bent due to camshaft failure, happens if you drive 250km/h for few minutes.

Lenin

lizard, do you do any datalogging? Do you know what your AFRs are? If at WOT your are running lean, this may do it. Just surprising that it is cyl#1. I would think cyl#6 would go first. Unless you guys are floating your valves buy over revving.

lizardjack

I lost 5 and 6 but that happened in a daily drive. I nailed her for 5 sec and bum - pistons gone. I've rebuilt the engine, changed everything that possible including new sender units injector and fuel pump. No issue since... Touch the wood)
I cannot recall if that was the 1st cylinder on Rasim's car last time though.
He's got a logger but not connected it yet. Too late now(((

320 dreamer

the problem is well documented on the e55 forums. the back cylinders go lean at wot under large pulleys due to the injectors going static during wot. not enough fuel so the back cylinders burn.
tuning technology motorsports fixed the issue by equalizing the fuel pressure with a looped rail and adding 550cc injectors then add a proper tune to scale the injectors.
i have this and my buddy has this setup on a stacked pulley car. if you put a fuel pressure sensor at the end of the oem rail you will see 60 psi max fuel pressure. loop the rail so the flow is equalized and the pressure drops to 55 psi. this what happens to the back cylinders as pressure is built at the front then moves back.
i have been testing this for ttm for about 4 months or so. final rail is done and injectors flow more than enough fuel. scaling of the injectors is done and the car runs like oem for idle and cruising. tuning continues to now bring the power out of the setup.

loudandheard

So no need for upgraded injectors or pump, right? Just a looped fuel rail.

lizardjack

IMO installation of the higher flow injector will not solve the presser issue. I'd even say they can make things worse at wot.
Conclusion - if the pressure drops at wot = the pump cannot cup.
Just imagine, injectors are (almost) continuously open at wot which makes the pressure to drop. Now if the bigger injector installed the pressure should drop even lower. Ok, maybe there will be enough fuel but will it be properly atomized?
I believe the "bigger" pump is the way to go.

320 dreamer

if your running a bigger crank pulley the injectors are the cure for any lean condition. the loop helps save any leaning of the rear cylinders due to a pressure drop.
the injectors allow for more flow. the loop rail equalizes the pressure so all cylinders get the same amount of fuel all the time. a bigger pump wont hurt but it wont fix your problem.
this has been proven on both the e55 forum and the crossfire forum
the pressure drop isnt from the inability of the pump to keep up but rather a false sense of pressure because it builds from the end of the rail backwards. loop it and the pressure is a more accurate representation of what the pump is flowing.
my friend is running a stacked setup (181 crank w/ a 69mm s/c pulley ) logging 22 psi and no lean issues at this time. when he initially had the sl55 fuel pump the 181 was fine but went lean with the stacked setup. add the 550cc injectors and he went pig rich 10 afr. scaled properly his afr is safe thru the rpm range
http://i599.photobucket.com/albums/t...8/7a7409cf.jpg