Balance Shaft Questions

[davnsam6]

my 91 talon tsi ,when i rebuilt it last year i did a balance shaft removal. a couple of times after really running it hard id start it up and it sounded like the bottem end was coming out of it for about a few seconds . was this due to the balance shafts being removed ? i have a 93 laser n/t 5 speed that im working on now and want to remove the balance shafts but it makes me nervose im afraid to lose the bottem end .is removing them really a good option?

 

[SinaiTSi]

My car just bent some valves and I have the head pulled am I'm gonna do a whole timing belt change. I've read that it is a good idea to have the balance shaft removed because there will be less chance that the belt will go bad. I've read many many threads about how they are only there for your butt and you don't need it. My only question is, is this absolutely true. My neighbor has an 800 Hp Nova and has been working on cars forever and tells me that there is no way that it is true, if you get rid of the balance shaft, then the whole engine will be out of balance and that is not good. He is not an idiot when it comes to cars, why would he think that? Are domestics different? I need real life examples or expertise about this, not just, "I heard from somebody". Thanks.

 

[1LE]

You don't need the balance shafts. They don't internally balance the engine. They do reduce vibration generated by the engine as a whole. The balance shafts also seem to be the cause of a LARGE number of blown up engines. I won't have a 4g63 *with* the balance shafts, too risky.

 

[davnsam6]

I'm in the same situation as you ,I'm skeptic about the balance shaft removal i did it to my 91 talon and was having trouble with engine noise .i really don't think it was associated . a Friend of mine did it to his eclipse and his is fine,he has well over 50,000 miles since he did his.I'm going to try it again on my 93 laser

 

[SinaiTSi]

You don't need the balance shafts. They don't internally balance the engine. They do reduce vibration generated by the engine as a whole. The balance shafts also seem to be the cause of a LARGE number of blown up engines. I won't have a 4g63 *with* the balance shafts, too risky.

Can you tell me why my neighbor with 30+ years of experience with cars and racing would think that you need them.

 

[1LE]

Can you tell me why my neighbor with 30+ years of experience with cars and racing would think that you need them.

He's probably thinking that they are there to internally balance the engine.

 

[SinaiTSi]

Yeah, that's what I told him too. He is the first to admit that he doesn't like imports (yes, I know that DSM were manufactured here in the US, but they still have the japanese engineered mistu. engine) so he doesn't spend much time with them. But, do domestics have balance shafts? And if so, for different reasons?

 

[1LE]

Most modern 4-cyl engines (import and domestic) have balance shafts to smooth out the harshness. Thing with domestics is that 6 and 8 cyl are much more popular. A properly configured V-6 will balance naturally. A V-8 is "very nearly" balanced on it's own... So, you don't here much about it in the domestic world. What you DO hear about in the domestic world is "balancing the engine" meaning "balancing the rotating parts". Proper counterweighting on crankshaft, etc... Mess that up and you're going to hear a loud bang from the engine bay in the near future

 

[SinaiTSi]

You've been very helpful so far, but I have another question. Oh yeah, I'm not trying to prove you wrong in any of this, I'm just trying to gather all of the facts.
You said that what you do hear about in the domestic world is balancing the engine. Counterweights and stuff, and if you do screw with that, then something will go wrong. So my questions is, the balance shaft doesn't actually balance out the engine? And if so, what does then? Thanks again.

 

[r10performance]

What you DO hear about in the domestic world is "balancing the engine" meaning "balancing the rotating parts". Proper counterweighting on crankshaft, etc... Mess that up and you're going to hear a loud bang from the engine bay in the near future

And what your V8 friend doesn't realize is that the 4G63's rotating parts are very well balanced from the factory.

 

[blackGSX2g]

If the balance shaft elimination job is done correctly, there should be no adverse affects on the motor at all. Only thing that would happen is increased oil pressure and one less thing to go wrong.

What was your oil pressure at on your other car?

I have done 3 balance shaft removals and none of the cars have had any problems. I would do it on any 4g63 I had.

 

[RoasT BeeF]

Yeah. If its done right there will be no problems. I really dont see how anything balance shaft related could be making any noise if you took it all out. Has to be something else.

 

[wolf20043]

Yeah. If its done right there will be no problems. I really dont see how anything balance shaft related could be making any noise if you took it all out. Has to be something else.

Definately agree. On all 6 I have done there have been zero problems.
Mike

 

[SinaiTSi]

Ok, so this is what I'm understanding so far, tell me if I'm wrong. The 4G63 and many other 4 cylinder engines have balance shafts for a little bit of a smoother ride and quieter interior especially at idle. As far as the engine itself being balanced, it is already has been balanced fairly well from the factory, which you dont' want to mess with that stuff. Larger engines such as V6's and V8's don't have/need a balance shaft because they are much easier to be balanced for ride and passenger comfort. As far as the engine, the engine must be balanced also through proper counterweighting as does all engines. Please let me know anything that I have forgotten. Thanks.

 

[wolf20043]

Ok, so this is what I'm understanding so far, tell me if I'm wrong. The 4G63 and many other 4 cylinder engines have balance shafts for a little bit of a smoother ride and quieter interior especially at idle.

Exactly right. With the eliminators I have put in I really dont even notice any more vibration after doing so.(although it is there, just not enough to feel it)
Mike

 

[gotlag]

Sounds like a good neighbor to have so don't doubt him or ask questions of him if he doesn't have all the information needed. Tell him the are spinning via a rubber belt and he will most likely change his answer. Like others have said, they are there to PRODUCE a frequency that then cancells the ones our engine internals naturally make. In order for something to effect the internal balance, it must be an attached pert of the rotating Assembly. That is why we don't have to balance oil pumps or camshafts.

Also if he his a problem with that, ask what the differece is in late model Chevy 4.3l v-6's. Some have balance shafts and others don't, even in the same vehicle line, all depends on the option packages you ask for.

 

[davnsam6]

i did the balance shaft elimination kit replaced bearings to block oil gallies .in a sense i didn't think it was the balance shaft being removed that was the cause. i know a few people who have done it with out any problems .i just needed to make sure that wouldn't cause the crank to be out of balance and spin a bearing

 

[RoasT BeeF]

i just needed to make sure that wouldn't cause the crank to be out of balance and spin a bearing

It wont. The word "balance" is what scares people. All those shafts do is eliminate vibration.

 

[JaxTalonTSi]

Regardless whether or not one thinks it's best to leave the shafts in or out, taking them out with the block still in the car is nuts. I'd wait to do it when it's time to rebuild the engine. All the crap you will go through to do the work with the engine in the car will not be worth it.

 

[davnsam6]

actually isn't it called a silence shaft

 

[SinaiTSi]

Regardless whether or not one thinks it's best to leave the shafts in or out, taking them out with the block still in the car is nuts. I'd wait to do it when it's time to rebuild the engine. All the crap you will go through to do the work with the engine in the car will not be worth it.

Have you actually done it while the block was still in the car and it was a pain, or are you just assuming it would be.

 

[Defiant]

Silent Shaft. Patented and licensed by Mitsubishi for companies like Porsche to use, for a fee.

 

[blackGSX2g]

Have you actually done it while the block was still in the car and it was a pain, or are you just assuming it would be.

I have done it both ways. When I did it with the block in the car, I just left the front shaft disconnected. I put washers behind the sprocket and tightened it down so it would not rattle. The only part of the BSE kit that I used was the stubby shaft, and it was $12. It would be much easier on a FWD (AWDs require the removal of the transfer case to pull the oil pan), but all in all it wasn't a horrible job.

 

[robmea]

why cant you simpily remove the balance shaft belt and leave the internals in the car because they wont be spinning with out the belt and that means that it cant break and shread your timing belt? is there a way that this would work?

 

[SinaiTSi]

why cant you simpily remove the balance shaft belt and leave the internals in the car because they wont be spinning with out the belt and that means that it cant break and shread your timing belt? is there a way that this would work?

That's what I was wondering too, for some reason though, I thought that I read that you can't do that. I could be wrong though, anyone know for sure?