bridfi

anyone out there running these 2.2 factory rods to 7500+ RPMs?

can they handle it?

yes, my cams make power to that point.
yes, i have neutral balance shafts.
yes, i have an aftermarket chain tensioner.
no, im not going over the 250 CHP point.

i really just want to know the question i asked, nothing else.

Witt

Most revving that high usually replace the stockers obviously which doesn't answer your question. My bigger concern in your case though would be the stock rings at those speeds.

bridfi

will the rings break apart?

Witt

I'm not sure what they are tested to, maybe the j body forum could better answer that. Engine builds that I've had my hands on in the past (non ecotec) stock rings are usually the first concern followed by cam lift vs. valve springs when exceeding a stock redline.

Cougar

A little off topic but Witt, I love that quote in your sig.

mrsilent13

well i was running my stocks up to 7200...they run fine.....i dont know about 7.5k....but good luck right now im getting some money together to do a whole new setup.....

domesticimportls

if u want to rev up that high go buy a honda. there is no point in having a cobalt rev that high.. the full out race BUILT ls that runs at NoPi only revs to 7200, and thats a full race motor..

Witt

If his cams are still making power to that point, he has every reason to rev that high.

ilovecars

iTrader: (4)

yea what he said

IonNinja

I was hoping to rev to around 7.2K once I got comp cams and a tune on built head & stock bottom end...

I think it should be fine...I hope anyway

Spanky's Monkey

iTrader: (6)

you'll be fine for a while. doubt anyone knows exactly how long that while will last but to be on the safe side i'd suggest eventually upping the rods before something breaks and then you'll be paying twice as much in the end.

oh duh the stockers won't last much past 7.2 or so. i almost forgot when i killed my first engine due to over-revving it hit just shy of 7.5 or so when i cracked a rod. the engine ran for a few months after that then the whole bottom end blew out.


here's the link >>>>>> https://www.cobaltss.net/forums/show...t=39388&page=2

bridfi

wow. looks like im gonna have to rebuild the bottom end sooner than i thought

i was gonna wait til next summer, but damn i really dont wanna throw a rod through my block

Spanky's Monkey

iTrader: (6)

**** a rod i threw eveything out. they showed me the hole it was at least a good 6 inch gap. i though it was pretty funny **** since it was on their dime.

bridfi

its out of my pocket if something happens. warranty has been gone. ******* GM.

so it wouldnt be funny to me, id look more like this guy:

i wonder if i can just hone my cylinders and drop in some SS rods with aftermarket 2.0 pistons while its still in the car... hmm....

Spanky's Monkey

iTrader: (6)

you should be good with the lsj rods. stroger steel then the mild l61 set.

bridfi

definitely.

i hear their good up to 400 hp or something like that

**** that im setting the limiter at 7000 til i can afford it.

i really dont want to regret making my bottom end explode.

Witt

If you used LSJ rods you would have to use GM's special piston set made for them in an L61 application. If you used an aftermarket LSJ piston you would put the piston into your head because the LSJ rods are longer then the L61 rods.

TurboTechRacing

iTrader: (24)

Look into the GM hand book on building it up.

I think it will be cheaper to get the Eagle rods and Wiseco 2.2L pistons. They will turn 7.5K just fine. It maybe a lot less work and $ in the long run of things.... Just a thought.

bridfi

learn something new everyday...

but since im wanting a high CR, maybe i can use them, hmmm... ill need to do some math..

ill have to do some research. because i can get some LSJ rods for cheap.

the only problem i see with doing that is if the sides of the rods will clear the very bottoms of the cylinders, because of the longer stroke of the crank.... does anyone know?