i saw my two cracked pistons tonight. It was fractured along the ringland. good thing the rings held it together not causing any damage to the sleeves. what do you think could have caused this? mechanic said it wasnt able to handle the boost i threw at it. what the heck? i was only using 2.8 / 16.5l psi. so what do you think?

 

It must have been detonating, possibly due to improper tune or maybe bad gas??

 

maybe so. it was tuned for warm weather and it went when it was 0 outside. i didnt have a chance to have it retuned for the cold weather.

 

Sounds like its a good possibility then that your engine went a little lean with the colder air and blew!

 

so wait you blew your motor yet you could still drive on it legitly

 

more details please.

 

#4 piston right

 

Yeah bro...you leaned out hard...

 

can you please elaborate on this motor blowing situation did you know you blew your motor right away or what

 

no i didnt know i blew it yet. i popped a dipstick and tried to change the intake manifold gasket but still it pops my dipstick. so i decided to have a compression test and found out that i have lost compression on 1st and 4th. both pistons are fractured the same way. i still drove the car for a good fifteen miles going to the mechanic. mechanic was suprised cuz it didnt leave any damage to the block because the fractured parts were held together by the piston rings.top part of pistons were in mint condition. il post pics later.

 

damn man another LSJ bites the dust

 

^^due to tuning....

 

ahh... just came from there bro... yeah your 2.8 leaned out and then went boom with the cold air..

trust me it gets better

 

motor is going together so ill have a built motor friday. i put in arp headstuds, cometic gasket, diamond pistons with total seal rings. they had to machine the rod for the piston pin to fit.

 

oh really.... it shouldn't been a direct replacement. I hope you stayed with a max of 9.5:1 compression though.

 

I'm guessing you don't have a wideband.

 

Ahhh self compensating stand-alones are amazing. 28psi at 0 degrees runs just as rich as 28psi at 90 degrees, all without ever touching the tune....Too bad i cant afford to put a 4,000 EMS into my cobalt.

 

the cobalts PCM will auto adjust too... problem is most people modify or disable the abilty of the PCM to do so.

or they're running a 2.7 pulley on 42 lb injectors... and just lean the hell out

 

im only running 2.8 + 60#. but with warm tune.

 

Im getting ready to do my upgrades with in the next week or so.Im running

2.7 pulley
65# injectors/harness
zex plugs
ecotec header
down pipe no cat
megan racing catback
injen intake

will i have to get it retuned with every season change? I dont wanna blow my motor it only has 1100 miles

 

i guess just for winter and summer

 

You got Deta-owned, just be glad your not picking chunks of connecting rod the size of quarters out of the oil pan.

I remeber that day 60 miles from home at the track in an 85 Dodge charger turbo. The hell with it, drove it home on 3 cyclinders and no boost, Misquito control was on patrol.