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Well bit the bullet and joined a cobalt forum incase I have any questions throughout this eventful journey hope yall find this somewhat interesting and may be able to provide some intelligent insight when needed!
So long story probably still long had to sell my camaro after I blew 3rd and 4th was tired of messing with the damn thing. Found the cobalt same day and picked it up for 2500 bucks kept going into limp mode and guy gave up so I jumped straight in and bought the zzp stage 2 kit put it in problem fixed also new brakes, battery, intercooler pump, gaskets etc literally everything drove it for a bit then mid race at 125 it makes a wierd ass noise and dies. Get put pill the plugs and number 2 plug is obliterated and I pulled while motor was hot but I don't even wanna got there. So pull the head and what do you know snapped an intake valve it went into the piston and chewed the head all up.
I don't know if your referencing my post or not but I'm just asking questions. I can see how asking that many questions in a row may look like I was excited but I would really be interested in seeing the answers. I asked if he honed the cylinders because when I built my engine no one could give me any good answers on what grit to use or if I should even hone them at all. I would be especially be interested in knowing if that valve bounced around in there and somehow managed not to damage the cylinder wall. I am also very curious if that head is salvageable or just fucked. Then with the very last question I would really like to know if this happened just running a stock motor at a safe RPM because it is very bizarre to just snap like that isn't it?
Can you explain to my why your putting DI Pistons in a NON DI car. IF i could underline that like 5000 times i would.
Mainly for cost effectiveness they hold more power than lsj pistons if you keep KR down. Also .2 lower compression (as if it matters) for turbo if i do go that route. No negative effects from it the injector fills the bowl and the plug is right on top to ignite it less sparatic spray of fuel.
Your cylinder wall didn't get damaged at all? Did you hone the cylinders to break the glaze? Are you putting a new head on?
Man that makes me nervous your valve just snapped. Do you have stiffer valve springs or anything?
Nope super lucky didn't mess up the wall just honed all of them so the rings can set on the new pistons. Just got an oem head to replace it for now may do valve springs in near future we will see.
Mainly for cost effectiveness they hold more power than lsj pistons if you keep KR down. Also .2 lower compression (as if it matters) for turbo if i do go that route. No negative effects from it the injector fills the bowl and the plug is right on top to ignite it less sparatic spray of fuel.
the lnf piston does not handle more power and it lowers the compression farther then .2 and the injector does not fill the the cup on the piston because the lsj is not direct injection so its not going to happen
Originally Posted by Cmorris24
May i ask how?
the lnf uses a shorter rod and a shorter compression height on the piston and a different piston cooling jet its angled different and smaller in diameter so the piston will clear it with the lnf rod being shorter then the lsj and the piston setting lower on the rod vs an lsj the chances of it having enough room to clear the gen1 piston cooling jet is very slim you would have been better off pulling the engine and fixing it the right way
the lnf piston does not handle more power and it lowers the compression farther then .2 and the injector does not fill the the cup on the piston because the lsj is not direct injection so its not going to happen
My mistake it lowers it .3 and I do understand it won't completely fill the cup and may not be as efficency nut will still work like normal.
the lnf uses a shorter rod and a shorter compression height on the piston and a different piston cooling jet its angled different and smaller in diameter so the piston will clear it with the lnf rod being shorter then the lsj and the piston setting lower on the rod vs an lsj the chances of it having enough room to clear the gen1 piston cooling jet is very slim you would have been better off pulling the engine and fixing it the right way
As far as the rod length its a .005 difference which is negligible in this case and wiseco shares pistons for the lnf and lsj and I believe it's the k1 rods that are also for both the lsj and lnf. Afullu big companies to be selling faulty parts to customers. Not trying to start a **** fest I just haven't found a reason why they won't work and I'm gonna try it if I'm wrong oh well it's a day job to put differnet pistons on my old rods and slap em in. I don't know people on this Forum so I don't know where your background on ecoteca come from but would you mind sharing where you have attained your knowledge from?
10-23-2016, 07:48 PM
