g4cs w/o balance shafts-good idea?

[kicker91laser]

I want to know if you guys running the g4cs block are running with or without balance shafts. If your not running with them, how many miles are on the engine? I have done some searching, really didn't come up with a clear answer on this. Any suggestions are appreciated.

 

[GVR4592]

I wish I had a digital camera, I'd take a picture of the pile of spun balance shaft bearings I have. Ditch the shafts, balance everything within .5 gram, get an aftermarket damper(very important), and it won't vibrate any more than a built 2.0.

 

[aero_sallee]

I wish I had a digital camera, I'd take a picture of the pile of spun balance shaft bearings I have. Ditch the shafts, balance everything within .5 gram, get an aftermarket damper(very important), and it won't vibrate any more than a built 2.0.

My 7bolt 4g64 doesn't vibrate much at all. Fully balanced with no balance shafts, stock mounts filled with window weld.

 

[kicker91laser]

I have always removed the balance shafts on my 4g63s, I was wondering if it is ok to remove them on the 2.4 application. Yesterday, I talked to JAM over the phone about machining prices and they had said that I shouldn't remove the shafts, for me to send them the shafts, they will grind them and install oversized coated bearings in the block. According to them, if I run the 2.4 w/o balance shafts, the harmonics created will destroy the engine-even if the rotating assembly is balanced. I am not about to install brand new balance shafts let alone reground ones. I am really wanting to know how many miles some of the board members have logged on their balance shaft-less g4cs'. If I need to, I will have it balanced and run a fluidamper on it.

 

[GVR4592]

I have always removed the balance shafts on my 4g63s, I was wondering if it is ok to remove them on the 2.4 application. Yesterday, I talked to JAM over the phone about machining prices and they had said that I shouldn't remove the shafts, for me to send them the shafts, they will grind them and install oversized coated bearings in the block. According to them, if I run the 2.4 w/o balance shafts, the harmonics created will destroy the engine-even if the rotating assembly is balanced. I am not about to install brand new balance shafts let alone reground ones. I am really wanting to know how many miles some of the board members have logged on their balance shaft-less g4cs'. If I need to, I will have it balanced and run a fluidamper on it.

That's where the aftermarket damper comes into play. The 2.4 cranks do have weird harmonics, but the Fluidampr does make a difference. If you're really worried about it you could get an aftermarket crankshaft that doesn't have the resonating issues. Balancing should be done on every engine even if it's just a street engine. If you want good information from somebody with a lot of experience with the 2.4, give Marco at Magnus Motorsports a call.

 

[AL92]

I have a 2.4 with about 1500 miles on it. I took out balance shafts.I bought a fluidampr.I didn't balance the engine either. I was told to balance it with flwheel and clutch and didn't have clutch yet when did the motors.I have heard the aftermarket parts are pretty well balanced but did use a 2.4 crank.

I have some vibration maybe but its not crazy.I don't have mirrors shaking or things rattling in the car but just feel a bit especially past 3500 or so. But also have poly inserts front and rear. I am pretty sure there are lots of guys with pretty good mileage on their 2.4s with no shafts. Some balanced the engine and some didn't is my guess.And some of my vibration might be exhaust resonance since have 3 inch and no cat.

I think its a good idea to maybe get the engine balanced just hard to get done in my city anyway.

I know lots of guys simply take them out of their 2.0 without balancing. Jackson might be a bit out to lunch on this but guess time will tell if I messed up or not.

 

[GVR4592]

It's a myth that aftermarket parts are balanced from the manufacturer. I've wieghed Wiseco, Ross, and JE pistons. They all claim to be balanced within .5 gram but none of them were. Eagle, Crower and Groden rods were all out about a gram. It might not seem like much but it adds up really fast.

 

[steel_3d]

Same experience here with Eagle and Wiseco. They're out by about a gram. After juggling pistons, pins and rods around, I got the piston/pin/rod assemblies within .1-.2 grams of eachother. Gotta be careful with juggling pins - the clearance with the piston pin bore has to be right.

Not sure how much difference a gram makes here or there, but for the price of a 50 dollar ebay scale, why not do it. Plus there's all kinds of other stuff you can weigh with .1 gram accurate scales Make sure you get one that weighs to 1000g with .1g accuracy. Rods are over the 500g limit of the cheap scales.

Most machine shops only have 1g accurate scales. Also, contrary to popular belief, they generally don't take material off rods and pistons, since the machining marks might create unnecessary stress risers that outweigh the benefits.

My crank and flywheel had some material taken out in balancing, but the clutch plate was apparently balanced.

PS: balance shafts won't save a badly balanced engine. They only balance the natural harmonics of the engine that you feel externally, they don't help the internal balance - the forces that the crank, bearings, rods etc feel. WTF is JAM smoking? They're often called silent shafts, since their purpose is to make the passenger's experience smoother, and that's it.

 

[92awddsm]

PS: balance shafts won't save a badly balanced engine. They only balance the natural harmonics of the engine that you feel externally, they don't help the internal balance - the forces that the crank, bearings, rods etc feel. WTF is JAM smoking? They're often called silent shafts, since their purpose is to make the passenger's experience smoother, and that's it.

Bingo! The balance shafts only soften external vibrations. They, in no way, counteract the resonance or harmonics of the crankshaft itself. That duty is controlled only by the harmonic dampener, hence the name.