Balance Shaft Removal??!?!?!

[Morphius]

Alright, first I will be posting something a little later regarding the plot Defiant so graciously posted for me because my balance shafts on the computer are out and I couldn't get it uploaded.

And note that we are all on the same team here. Including me. I'm an enthusiast just like all of you.

Originally posted by onegee
i read earlier in the thread that a motor wouldn't last 150k mile w/o BS. what is the validity of this statement? i plan on getting a new motor soon and if the BS kills the longevity of it i might opt against it.

Big 3 all have design criteria or specs that for any component, the expected life is 150K. (although DCX is looking at upping the ante and pushing it to 200K) There are DCX specs that each component must comply to. If they don't, they don't go into production. There is a rare occasion that a part is changed very late in the build phase and it is approved before the supplier has completed all the testing showing that they have met the PreProduction Part Approval Process (PPAP) And yes every now and then, some of those that are approved for shipment before PPAP, come back to bite us (big3) in the butt. That's when you hear about a recall on a vehicle. Or a recall can be a likely case where typical testing never found the error. But was still found and ethically should be corrected even though there have been no cases reported by customers. (ie. likely the case with the seat belt recall on our DSM's) Vehicles have probably the highest liability of any product out there.

Your motor will most likely last 150K or more without balance shafts. However, you run the risk of unseen damage to the electronics and other engine mounted components. Like I stated earlier, vibration kills electronics. If you find you are changing the power transistor every 30K, then I'd speculate that it is likely due to the b-shaft removal. With them removed it might appear to be OK and nothing significant, but just because you can't tell the difference doesn't mean that there isn't added vibration from removing them. There is, you may not be able to detect it.

As an enthusiast, I'd say remove them. I'm neither for or against it. I'm just clarifying that they are there for a reason. Reliability of the overall vehicle system to achieve the milestone of 150K miles.

Originally posted by Buck
The odds are your motor won't survive 150K miles WITH Balance Shafts - that has been damn sure documented!

I disagree. On a stock car (or not heavily modded), driven halfway respectfully, and maintained properly, the motor will last 150K miles or more. I think that there are enough enthusiasts here that can speak to that.

And I agree it is a potential failure point. But the benefits of having the balance shafts on, over the life of the vehicle, far out weigh the bad. The probability is low for this failure to happen. This applies for STOCK or near stock vehicles. Just as if you bought a new car and installed a supercharger, your warranty is usually voided. Why? the vehicle was not designed to withstand that increase in performance for the life of the vehicle. (150K) It may well survive that, but the big 3 can't design for that. Expecting that a kid slaps a 20G turbo on, with all the other bells and whistles, and the car should still survive 150K miles? If they did, believe me, you'd be paying ALOT more for a new vehicle. Parts would cost more. Testing would take longer as there would be more variance to the overall vehicle system.

Now, honestly, I just recently almost fell victim to a b-shaft belt failure. Long story short. I got my fuel system fixed recently and while the car was warming up, the b-shaft belt broke and found itself into the timing belt and took a trip around the loop, cracking the top timing belt cover as it slapped the cover on it's journey around. YIKES!! Yes, it was an OEM belt with only 30K miles. But why does this not surprise me? Because like most of you my daily driver is not stock. I drive it like I stole it. I seriously rag on the car everyday on my way to and from work. Why? I think you all can answer that one. Given the car is not stock and I don't drive it like a normal person, then I should have increased the intervals for belt changes.

My advice would be that if your car is modded, increase the belt change interval and you won't have an issue. 60K intervals is for a stock car driven like a sane person. I don't think any of us (or many) here fit that criteria. Including me. We are all pursuing more performance, pushing the limits on our cars daily. Or remove them alltogether. Choice is yours and you know the pros and cons.

 

[GaRn]

HEY! i have an idea!! How about lets shut up?! yea! shut up! sounds great huh? , seriously, his argument isnt getting anywhere, your all trying to justify one thing or another, how bout just doing what you wanna do to your car.. we all agree it isnt gonna have any side effects for a LONG while, so why should you care for someone elses car then?

give it a rest..

 

[Taboo]

Originally posted by BUCK
I greatly respect your opinion Taboo so let me see if I have this straight...

So the Higher RPM's had to do with the Oil Pump Failures - NOT the Mirage shaft with the identical Bearing Surfaces - because Belt Tension is Belt Tension is Belt Tension - & that Belt Tension is ALL the side load that bearing will see.

That is slightly incorrect. The tension on the belt between the intake cam and crank sprockets is not dictated by the tensioner but the resistance of the valvetrain and the torque of the engine. The higher the resistance of the valvetrain - due to stiffer valve springs and/or increased valve lift of aftermarket cams and torque of the engine, the higher the side load on the oil pump drive gear is going to be - no matter what tension the tensioner puts on the belt on the other side of the crank sprocket. Since the helical gears of the 91+ oil pump have a tendency to spread apart with increased load and RPM, the lack of appropriate support will eventually cause problems. The very first sign is going to be fluctuating oil pressure as result of the varying clearance of the drive and driven gears at high RPM or loads - which may consequently damage the inner surfaces of the oil pump housing and bores of its gears. Once the clearances increase, the wear will only accelerate. The gears of the oil pump simply don't like the fact that most drag racers use the throttle of their high-torque engines with higher-than-stock redline in on/off switch fashion. The balance shafts spin three times faster than the crank. If one raises the redline to 8.5K, the balance shafts spin 3000 RPM faster (at 25.5K RPM) than stock (22.5K RPM), and, of course, we all know what happens to let's say unbalanced turbos and their bearings or what out-of-balance wheel feels like...

 

[SpoOLxExO]

I have been reading this thread and seeing Im prolly the only one on this tread with relevant EXPERIENCE with the matter here goes...

My first DSM was a 1990 Tsi AWD. it had 184k when I bought it. I was just like the rest of you guys. Believing everything I read, getting duped into buying a 50trim even though all I have is a fuel pump, etc.

That car while seeing 28psi sometimes on the stock bottom end, lasted to over 210k miles a finally failing after, well at least 3 years of hard abuse I can vouch for. This car has balance shafts in it.

Fast forward to my current DSM a 92 GSX. I bought it with a broke timing belt. Did the topend rebuild, and drove it for 350 miles.
Front balance shaft bearing seized itself to the shaft and spun in the bore in the block, causing metal shavings to screw my engine and cause .010" of endplay (Crankwalking 1g!?!?! WTF!? I know, I know)
I Bought a JDM GVR4 shortblock and removed the balance shafts with the mitsu kit, and the Vfaq method. Well, Maybe I shouldnt have re-used the 92 oil pump gears with 135k on em in my "New" motor. Long story short, I overreved the engine to 10k and caused the oil pump falure.

So both views are kinda true in my case.
If you leave the shafts in, yes the engine can live to 200k with proper maint.
And if you remove them, shit can happen, but you know what? I'm not convinced that removing them is a dumb move, cause it was the balance shafts that screwed me in the first place.
I think that if you remove the balance shafts that every piece on that side of the engine should be replaced with genuine new parts. I'm talking the oil pump cover and gears, all pullys, all belts, all seals etc. Because there are too many variables in different instances to know weather or not this is a smart thing to do.
However if it works for my NewENGDSM brother Rizz, who throws out 490 WHP on the stock engine w/o B/S's , I'm pretty sure that with proper intallation with new parts, it'll work for me too!

 

[RiceKiller_TSi]

Uhhh... kinda noob question but,... uh... do you HAVE to remove the balance shaft? Why not just remove the BS belt and be done with it? Bearings cant fail it they dont rotate right? Wouldnt that be easier? Aside from loosing the weight of the part with a complete removal.

 

[SpoOLxExO]

The problem with that is, you can't just leave one counter weighted shaft connected and not the other.

In other words is the same to have the balance shafts, or have them completley removed, if you just take the belt off the front one, the rear shaft is still connected to the oil pump, whihc is drivin by the timing belt. That shaft will still spin, but create more vibration then if they were removed, or still installed.

I know that the price of a balance shaft removal kit looks like an intrigueing inexpensive mod, but there are more than meets the eye. If done correctly you will realize better revability and increased oil pressure. if not you can loose your engine, simple as that. Besides Ricekiller_Tsi, if you read the vfaq on how to remove the B/S, you would realize that you can perform the removal "In the car". This is where you still remove the oil pump cover to install the stubby shaft, but you leave the front shaft in the block, due to the fact you can't pull it out when its in the car. So you just reinstall it like it was, blocking the bearings, but you still removed the rear shaft, and replaced it with the stubby.

Wow, thats alot of typing.

Bottom line, B/S removal is a good idea...only if your going to perform it correclty and with new parts for the side of the engine.

 

[Taboo]

Originally posted by SpoOLxExO
you leave the front shaft in the block, due to the fact you can't pull it out when its in the car.

That is incorrect. I've removed both balance shafts (which includes reversal of the front balance shaft bearings) with the engine in the car on countless occassions.

 

[RiceKiller_TSi]

Originally posted by SpoOLxExO
The problem with that is, you can't just leave one counter weighted shaft connected and not the other.

In other words is the same to have the balance shafts, or have them completley removed, if you just take the belt off the front one, the rear shaft is still connected to the oil pump, whihc is drivin by the timing belt. That shaft will still spin, but create more vibration then if they were removed, or still installed.

I know that the price of a balance shaft removal kit looks like an intrigueing inexpensive mod, but there are more than meets the eye. If done correctly you will realize better revability and increased oil pressure. if not you can loose your engine, simple as that. Besides Ricekiller_Tsi, if you read the vfaq on how to remove the B/S, you would realize that you can perform the removal "In the car". This is where you still remove the oil pump cover to install the stubby shaft, but you leave the front shaft in the block, due to the fact you can't pull it out when its in the car. So you just reinstall it like it was, blocking the bearings, but you still removed the rear shaft, and replaced it with the stubby.

Wow, thats alot of typing.

Bottom line, B/S removal is a good idea...only if your going to perform it correclty and with new parts for the side of the engine.

Makes sense, I know that the kit is inexpensive but i've read that the removal process is a b**ch and that is what i was trying to get around I would much rather do it right anyhow I was just curious. BTW what VFAQ? At VFAQ.com?

 

[RiceKiller_TSi]

Look I want my balance shafts the hell outta there I just need more info on how to do so... I'm scanning through my Chiltons as I type. I've got 205k on my car BTW with no problems from shafts. I "do" like the idea of no snappy snappy of ye ol belt though... I HAVE come close. Really close. Last timing belt change it appeared as though a rat had chewed it.

 

[BISHILVR]

Originally posted by kpt4321
Are you planning on providing us any information with that, or are you just going to roll your eyes and tell us you're an enginer? Frankly, I don't give a ####; I'm an engineer too, and it doesn't mean shit for this scenario as long as you're not retarted.






I'm an anal engineer, and even I think that they should come out. If that's not a good reason to yank them, I don't know what is!

yeah, what he said.....anytime an ANAL ENGINEER tells you to YANK YOUR SHAFT you should listen to him!!!!

 

[set3422]

Ok here's the relationship bewteen the rearshaft and oil pump gear/sprocket. Oil pump gear and oil pump sprocket were all balanced together as a whole assembly with the rearshaft.

Most people keep the oil pump gears aligned, but felt it was not necessary to keep the oil pump sprocket aligned. This is one of the factor that contributes to thrust wear on the oil pump gear shaft. Now probably I have just made some enemies for saying that. WTF would I want to keep the sprocket aligned with the crank pulley and cams when rearshaft is deleted. Read first paragraph.

The oil pump sprocket is considered part of sigma mass. The triangular indentation serves two things. To check if the rearshaft is in phase. The rearshaft still can 180 deg out of phase if the sprocket aligns. To correctly check if the rearshaft is really in phase is to take out the 10mm (left side of ac comp bracket) and stick in a 6 inch screwdriver.

Without the indentation you could still have the rearshaft in phase by what I wrote on paragraph above and check if the front shaft sprocket is aligned. So why did mitsu engineers put the indentation there? The indentation also can be found on 1.6L mirage where it doesn't have a rearshaft. Good luck.

 

[Taboo]

Originally posted by set3422
Oil pump gear and oil pump sprocket were all balanced together as a whole assembly with the rearshaft.

ABSOLUTELY not true. Balancing the balance shaft would make it useless - when it comes to cancelling the vibrations of the engine. How exactly do you balance an assembly that's unbalanced un purpose? Also, it it was true, one would have to replace the entire oil pump + its sprocket + the balance shaft as complete assembly any time he replaces any component of the assembly - which would be definitely mentioned in the factory service manual. There are absolutely NO indications that the sprocket, gears or the balance shaft would be somehow balanced in ANY way.

Originally posted by set3422
Most people keep the oil pump gears aligned, but felt it was not necessary to keep the oil pump sprocket aligned. This is one of the factor that contributes to thrust wear on the oil pump gear shaft.

Aligning the oil pump sprocket (and therefore the counterweight of the balance shaft) in relation to the crank is needed ONLY when the balance shaft is utilized. Once the balance shaft is replaced with the stubby shaft the position of the oil pump gears or the oil pump sprocket in relation to the crank is absolutely unimportant.

 

[onegee]

Originally posted by BUCK
& the ODDS are against you making it much further - you are the EXCEPTION - I sincerely wish you the best of luck - you NEED it.

Also the comment you were referring to MAY have been one that MAY have been posted by a knowledgable Chrysler Engineer stating the ELECTRONICS on an engine MAY not last 150K miles without balance shafts - he MAY well be correct... I absolutely do not differ with that opinion in any way.

geez..whats ur problem man? there is quite a bit of dsm 1g turbos with more than 150k miles running fine where im from. not all of the are ub3r super fast drag racers, but hell they still run.

all i said was my motor has 152k miles and u go ahead and basically say "ur screwed, ur sh1ts going to break" . Kinda rude dont you think? anyway, quit with the "YMMV" type talking. You make blanket statements that dont apply to everyone. If the engineer said it wont last fine, but quit acting so pompous about geez. If you were being sincere about wishing me luck, thanks. if u were being sarcastic . anyway, all my engine electronics are fine. the thing that is wrong with my car is number one's ring. hence the reason why im asking q's about what to do about my new motor im getting.


back on subject: Will upgraded motor mounts help to cancel out the added vibration? or add to it? i have prothane motor mounts now so im just wondering.

happy holidays ppl

 

[MNGSX]

Originally posted by set3422
Ok here's the relationship bewteen the rearshaft and oil pump gear/sprocket. Oil pump gear and oil pump sprocket were all balanced together as a whole assembly with the rearshaft.

On these and most production line engines (esp I-4s) not even the reciprocating assembly was balanced as an assembly.

The balance shaft itself is inherently off balance as it is designed to counter an "imbalance". Which is why they sometimes take out bearings and do bad things when those go. The bearing is subjected to a side load that sweeps 360 degrees around the axis.

Example, When the weight is rearward the b-shaft bearing is loaded hard against the part of the bearing towards the firewall. It's like a catamaran team leaning way out starboard into the wind. The forces of the reciprocating assembly go thru the main bearings into the block. The b-shafts transfer an oposing force into the block in time with it. Canceling the block movement only. I can't tell you how many industrial 4 bangers regardless of fuel... Gas, Diesel, turbo diesel, LP, CNG don't have balance shafts despite the same crank configuration as a 4g63. It seems when getting a job done is more important than selling something everything means buisness or it is'nt on the engine. Some of the gensets I work with the engine is basically going thru a dyno pull at a fixed RPM for DAYS on end... that is just normal operation.

In reality the shafts just prevent reciprocating assembly harmonics from transfering thru the motor mounts as much. They don't change the load on the main bearings at all.

The raw b-shafts are cast and a basic QC check of the casting then final maching is performed. That is it. It may be only 1 out of a 100 get checked.. it may be more. I don't know the assembly line proceedures and some of these backwoods union auto workers don't either.

Crank counterweights are just drilled to get them within a factory tolerance... same with rods and pistons ETC. There is a specification for an acceptable range for each part. That is it.

Softer vs Harder mounts don't change the vibration itself. Harder means more vibration transfered to the frame. OE or soft less.

 

[Morphius]

Originally posted by Defiant
Here's an image that Morpheus asked me to upload, because he couldn't get it to upload from his end. I suspect his modem is missing its balance shafts.

As you can clearly see, this is a global view of Africa, showing how the practice of engine balancing progressed from Ghana, across through Egypt, and on to the Silk Road where Marco Polo brought the idea back to the Medici family of Venice (who laughed his ass back to Siam).

Um.... or, it's something else. Morph will be along shortly to elucidate.


I hope.

Urrr.. well, yes. I can't explain it but my modem is missing something as I have been unable to post this plot. Special thanks to Defiant for being the unbiased poster of my data. Although the theory involving Africa, Ghana and Egypt is well.......... good, in this case it is not the answer. (This is the best I could provide given the report is setting on my desk 1400 miles away. I just happen to have an electronic copy of this in my email at work that I accessed from here.)

Now, trying not to bore you with techno babble...... first let me note that this is a 6cyl engine. What Defiant has posted for me is spectral plot taken off a clutch pedal. It shows order vs rpm. Amplitude is specified by the gms or the color chart on the right. Looking at the visual cues to the right, red is bad; blue is good. The rpms at which the graph shows red, it will nearly put your foot asleep from the vibration. Tingly feed back through the pedal.

As you can see there is a lot of vibration going on that you don’t detect. Causes? They are or can be a function of the following:

1. Any mass rotating: crank, rods, pulleys, gears, cams, accessories.
2. Firing order/combustion process.
3. Injector pulses. While under the hood can you hear your injectors clicking away? Depending on brand, type, and fluid pressure, noise created can be transformed into vibrations.

There is some good discussion here:
http://www.thrashercharged.com/tech_htm/adv_engine_design.shtm

In the case of the 4cyl and balance shafts I agree that the primary job of the balance shafts is to dampen primary and secondary vibrations. But is it possible that they also help dampen other vibrations present?

 

[kpt4321]

I can't even believe I'm replying to some of this crap.

Originally posted by Morphius
Now, trying not to bore you with techno babble...... first let me note that this is a 6cyl engine. What Defiant has posted for me is spectral plot taken off a clutch pedal. It shows order vs rpm. Amplitude is specified by the gms or the color chart on the right. Looking at the visual cues to the right, red is bad; blue is good. The rpms at which the graph shows red, it will nearly put your foot asleep from the vibration. Tingly feed back through the pedal.

So, you're telling me that the clutch pedal on a 6 cylinder equipped car vibrates? Whoa, sweet. I better go re-install my balance shafts.

And, while we're making irelevant information relevant, I might as well turn my boost down and paint my car a different color, because of what that graph says.

As you can see there is a lot of vibration going on that you don’t detect. Causes? They are or can be a function of the following:

That's like, not new or exciting news in any way shape or form.

1. Any mass rotating: crank, rods, pulleys, gears, cams, accessories.

That should read "any unbalanced mass rotating."

2. Firing order/combustion process.

Firing order doesn't create vibration. It may effect the way it shows itself, but it certainly is not a cause.

3. Injector pulses. While under the hood can you hear your injectors clicking away? Depending on brand, type, and fluid pressure, noise created can be transformed into vibrations.

This is my favorite part.

So, the balance shafts are there to cancel out vibrations from the injectors (or that is one of their purposes). That's probably the FUNNIEST thing I have heard all week.

Injectors are simply solenoids, where a small object is moved by an electric current. Thus, they do create a small vibration, each time they open and close.

Of course, then you consider a few things... the rate of opening and closing of the injectors can change independant of balance shaft speed. The direction in which they impart forces on the head/motor/car is not the same direction in which the balance shafts cancel vibrations. Should I go on?

Let's say you have a SAFC in your car. You lean it out a few percent, so the injector pulsewidth is a bit shorter, and these vibrations caused by the injectors are different. Do the balance shafts read the airflow signal, and then do calculations, and then change their mass/rotational speed in order to cancel out the vibrations from the injectors?

The blinkers use relays to turn on and off, where a metal conductor moves back and fourth. This is just as loud, or louder than the injectors. Do the balance shafts cancel this vibration out too?

Absolutely rediculous.

There is some good discussion here:
http://www.thrashercharged.com/tech_htm/adv_engine_design.shtm

Which explains that balance shafts are there to cancel out the secondary vibrations of the pistons and rods, which I have been saying for about three pages now. It also doesn't say that the balance shafts cancel out the vibrations from the blinkers, headlight relays, or the passenger tapping his foot to the music.

In the case of the 4cyl and balance shafts I agree that the primary job of the balance shafts is to dampen primary and secondary vibrations.

No. Their primary AND ONLY job is to cancel out the SECONDARY vibrations of the pistons and rods. THAT IS ALL. Even your stupid article is verifying this!

But is it possible that they also help dampen other vibrations present?

Survey says....NO!

 

[Defiant]

Originally posted by Taboo
And I don't hear of too many Mirages with 16 70psi valve springs, aftermarket cams with higher lift or engines producing over 400 pounds of torque with 8.5K redline, do you?

Well of course not, Martin. Those guys are all sleepers. And 'way scary-fast, too.

 

[tanner261]

Vibration is a huge issue for component survival (O2 sensor, injectors, TPS, Coil Pack, wiring harness, etc.) on single and twin cylinder powersports engines. The harmonics in these engines kill O2 sensors, TPSs, and their NVH can sometimes exceed the limits of the injector. It is also a huge issue on automotive applications. This is the point the engineers on this board are trying to make, NVH kills parts.

I've seen components fail due to vibration, both on a vehicle and on a shaker. Mitsu put the BS in the engine to make these components last longer, and so that your daily drive to work isn't annoyed by a vibrating steering wheel.

The pros for removing the BS far outweigh the cons. You will most likely never see a component failure from BS removal. I'm in no way defending leaving the BS in the engine.

My BS are removed, my idle is 900 RPM, and I have Prothane motor mounts. My steering wheel doesn't vibrate at the 900 RPM idle; it did at 750 RPM. Oil pressure is increased, and I don't have to worry about the BS belt taking out the timing belt.

 

[90AWDTalonTSi]

http://www.thrashercharged.com/tech_htm/adv_engine_design.shtm

I'm sorry but TRASHER is one of the worst places to get any info from. When was the last time they helped/sponsored/put out a good product/or not overly eggagerate their HP claims.

I'm not saying that they are wrong, just watch who you get info from.


*No hatred aimed at Mike Dye (C-Ya-Racing) also associated with TRASHER. He's a stand up guy. If the info came directly from him

 

[Streetwize]

I'm new to DSM's but I've been building race motors for well over 20 years.

I should research this more before asking but, when the balance shafts are removed, what becomes of the bearing journal oil feed passages that the shafts ride in? I would assume that the oil feed to these journals must be blocked somehow or else a pressure drop would be seen across the entire oil circuit of the motor.

Second order harmonics are not only transfered through the block but they can also be transmitted into the rest of the drivetrain, particularly in a manual transmission. I agree that the cancellation of harmonics makes it easier on the main and rod bearings as well as possibly minimizing torsional stresses on the crank though stabilizing the case (block and caps) that hold it.

What concerns me is the "Second Guessing" of running a motor without a component that was integral to its design, the 2.0 motor/block was designed around the use of balance shafts. I think to remove them in a racing motor would be fine when combined with a lighter and stronger race style crank/rods and pistons where the reduced rotating and reciprocating mass would proportionally reduce the inertia of the crank (at any given RPM) and by doing so, reduce the severity of the harmonics transmitted to the block. I'd need to do some more studying of the block to decide whether or not I would do it with a standard factory tolerance rotating assembly. I just bought a 6 bolt block that I intend to tear down for study. I do know from racing 9 second Yamaha V-max motorcycles (70 degree banked V-4's with balance shafts) that removing the shafts makes more power at the crank but induces more vibration to the block/transmission/driveshaft,(V-maxes have torque shaft drive, not belts or chains). I only ran them without balance shafts on bikes that would be converted to chain drive.

 

[GSXlaunch]

Streetwise, as for the oil passages that the shafts ride in or rode in, they are blocked either by new bearings part numbers MD103722 (rear) and MD040597 (front) or by the old ones if they are removed carefully enough. If done right oil pressure should rise a bit.

I actually just removed my balance shafts and am in the process of putting everything back together. I really cant grasp what the big deal is here. In a daily driven car that does not see any track time I would not take them out...however, in car that is more perfomance oriented, in my mind there is no question these things should come out. To name a few, you get a bit more oil pressure, much less chance of something breaking and taking out the t-belt, less rotational mass, less weight...I just looked at the qtr mile times and a ton of guys that are running 11's or 12's (with stock internals) are running with no balance shafts. I haven't read too many post where someone documented a serious issue as a result of removing the shafts. Infact, I havent read any. You might have less inertia out of the dig, but I'm a fan of "rev higher and launch harder". In my case, the next time I drive my car I will have removed the balance shafts, added a fidanza flywheel, ACT 2600 and an FMIC so I will not be able to pin point the performance gains by removing the b-shafts. However, when I removed them from my old Conquest 2.6 T motor I noticed the engine would rev much faster once it got above 4K. The vibration wasnt too bad, besides the 4G63's are extremely well balanced from the factory. Just knowing that the engine will have more oil pressure makes it worth the 40 bucks and 3 hours of work.

 

[heavyD]

HA HA HA!! Only engineers could make a post this long and still end up providing no useful information that anyone mechanically inclined couldn't figure out in the first place. Yes Morphious, vibration is bad for anything, but fuel injectors, power transistors, & coil packs are just coils & solid state components that can handle a fair bit of abuse. Yes extra vibration may damage one of the components but they may last forever in those conditions. You can't prove it either way.

Here's what we know:

Balance shaft removal good:
higher oil pressure, less rotating parts, no balance shaft belt to break and cause major problems, minor increase in engine responsiveness

Balance shaft removal bad:
increased engine vibration and slight vibration in interior, certain electrical/mechanical components MAY degrade or fail over time.

Frankly I haven't seen a thread at this site with guys complaining that removing the balance shafts caused components to fail but I have seen alot of complaints about the balance shafts belts failing causing major damage. In fact when I got my timing belt changed at 56K miles you could see that the old timing belt was in pretty good shape but the balance shaft belt was worn to the point that I may have been lucky that it didn't cause catastrophic failure before I got it changed. I see more pros than cons to removing the shafts, as if I have to replace a coil pack or injector over time, big deal! Hence my car now doesn't have balance shafts.