Hey guys I know I know this subject was talked million times. Short story, my first engine using gsc racing balance shaft for last 5 years but I was always feeling some vibration and sometimes hard gear shifting at high rpms 8000-9000rpm maybe because of this racing balance shaft maybe not. Now I am building second engine and I have stub shaft and gsc racing balance shaft and I just can't decide which way should I go. Do you guys run those gsc racing balance shafts on high hp or just stub shaft and call it a day. Thanks!!

 

The balance shafts are there to reduce the secondary imbalance in all 4 cylinder engines including the 4G63. The racing balance shaft or the stub shaft both eliminate the vibration canceling from the balance shaft system. So with either you will feel the same level of vibration. The racing balance shaft may do a better job of supporting the oil pump. Opinions are mixed on this. That is why some run it.

 

Thanks a lot. Yes I have seen mixed opinions about stub shaft and racing balance shafts. I have seen people damaging oil pump housing with stub shaft and also I have seen people running 30k+ miles with stub shaft with no problem. I am leaning toward to use gsc racing balance shaft but I just want people opinion. Thanks!

 

The stub shaft isn't any less supported than the GSC shaft, the backside of the oil pump case supports the small gear. Just make sure you use an OEM stub shaft.

 

Yes I will use oem stub shaft. I measure gsc racing balance shaft for runout and gsc racing balance shaft brand new have 0.0015-0.0017 runout.I dont feel comfortable installing shaft that is out of round and spinning 2x amount of the crankshaft. I will not use that shaft I will use stub shaft.

 

Everything gets a stub shaft.

These shafts go on the small oil pump gear, the gear that isn't even loaded by the timing belt. It doesn't need the support of the balance shaft.

 

May I ask why yall want to get rig of the factory balance shafts so badly? Is there a particular problem with oem shafts?

 

Even though reducing engine vibrations in the car is a good thing, there are a few decent reasons to remove the balance shafts.

1. If balance shafts break in a high powered build they can ruin your motor through debris or a sudden drop in oil pressure.
2. There are more parts to buy when you do your timing belt replacement.
3. If the balance shaft belt snaps or comes off, it can lodge itself between the crank gear or timing belt tensioner and cause you to skip gear teeth. Since the 4g63 is an interference engine it can self destruct.
4. If the balance shaft belt snaps or comes off, it will cause your engine to vibrate intensely since you'll still have the opposite shaft on the oil pump, which normally counters the top shaft in the correct phase, spinning freely.

My personal opinion is this. Stock Turbo and Stock Block? Keep the shafts

Built motor and aftermarket turbo? Take them out since you're already in there.

 

Balance shafts are there to reduce NVH, they have nothing to do with engine longevity or reliability. So when building an engine, they're just extra parts that can fail. So they get deleted.

 

After removing shafts are the engine vibrations noticeable at all? Does it put some extra wear on engine mounts? Even though the Evo is in fact a rally car but still the shafts were designed for a reason right? Or just simply to give it some comfort?

 

Yes, yes, yes and no.. The "benefits" far outweigh the certain consequences of not running your balance shafts. I'm with jacks trans on this one. Plain stupid to delete balance shafts unless you're doing a drag build with very few intended miles on the engine.

https://jackstransmissions.com/blogs...balance-shafts

 

Thanks for the info! Appreciate that! I'm putting the block internals together this weekend and now I'm surely keeping those shafts inside

 

i have a stock block/stock turbo with balance shafts removed. was not by choice, was not even asked. annoyed by it, wish i still had them. just get good belts and keep on top of maintenance.

 

Oh yay. Repeating age old misinformation.

 

Could you please be more specific on what’s exactly the misinformation?