I was cruising GM Parts direct and I noticed these little Balance Shafts.

http://www.gmpartsdirect.com/results...umber=88958615

If the link doesn't work just cut and paste into your address bar. Anyhow, my last car was a Sentra SER Spec V, and alot of us Spec V owners just yanked the damn balance shafts out of the motor since they rotated at twice the speed of the crank. They robbed horsepower and raised reliability issues all for the sake of keeping the everyday driver happy with engine vibrations. Just out of curiousity, has anyone else felt the need to investigate taking these things out or is just a bad idea for the Ecotech motors? I haven't heard of anyones failing in our cars yet, has anyone had a prob with them?

 

I honestly don't know but I have heard of what you are talking about.

 

You cant just take the stock ones out, as you need the gears on the shafts for the chain that turns the water pump.

We can get these for about 299.99 + shipping. Let us know if you are interested.

 

I was hoping someone would say they have something along these lines for our car, but it depends on where exactly the balancers are at on the motor as to whether it can be done.

http://hpautoworks.chainreactionweb....roducts_id=214

 

http://www.ecotecforum.com/forums/showthread.php?t=450

 

The neutrals that GM offers would probably be the best way to go, once I win the lottery and can afford the labor that would charged to perform this operation.

 

I'm glad someone posted the link above to the Ecotec forum. We discussed this a while back. First of all, if you plan to do this, be sure the shafts will fit your LSJ block. Those are L61 parts. Second, realize the great expense your are planning on just to get a few extra horses and a lot of vibration. I just don't think it's worth it.

 

level zero motorsports has a kit for a full balance shaft delete. more worth it than the neutral shafts IMO because you are removing a large amount of rotating mass from the engine. It wouldn't be a first mod, but if you're trying to get every last ounce out an M62 setup. and already have the standard bolt-ons, headwork, and cams done, then this could be a worthwhile mod. I won't vouch for gains 100%, but on the old chrysler 2.2/2.5 turbo engines, balance shaft delete was good for 15 whp.... worth more than a CAI that people are always glad to pay ridiculous amounts of money for.

 

My friend has an SRT4 and he just had his pulled out. The car still runs fine.

 

Well, this car isn't an SRT4. That won't work on a Cobalt.

 

Do have a link to somewhere saying it's a L61 specific part? It would be nice to know so I don't pursue this any further. But I would disagree on the vibration point. If the Qr25 didn't produce too much vibration without balance shafts then I doubt an Ecotech will, especially the 2.0. Whether it's worth it or not is all about who you ask.

 

From what I have read, the only reason to change out the balance shafts is if you are planning on going above 7500 RPMs. Since you have to change out the valve springs to do this you are talking about major overhaul. If doing all that you may as well go ahead and swap the cams, pistons and connecting rods out while you have the whole motor apart.

 

Informative, thanks. It's a quick job like on the QR25, thanks.

 

Not worth it? It can cause balance PROBLEMS if you do not remove it if you plan on revving to 8k+.

I will definetly be removing/replacing mine!

 

Same here... spare motor is getting stripped down next week to get the cylinders honed and to send out the head to get ported and valve train upgrades...
crower rods. mahle pistons (or the diamond ones) neutral balance shafts, of course get whole rotating assembly re balanced and I'm good to go... hopefully be done by springtime

 

On the GMP LSJ build book, they took out the balance shafts and replaced them with the blanks or whatever, just the plain cylinders. So they DO have them for the LSJ and there IS a power gain. According to GM the balance shafts take 10hp to spin. I think it's in Part 2, not sure what page.