Balance shaft removal pro's and cons

I was thinking of removing the balance shafts on my colts engine, (4g63 turbo) and i was wonderin if anyone could give me the pros and cons of doing this.
thanks
Dan

Pros:
-more power!
-no chance of the balance belt breaking and taking out the rest of the engine

Cons:
-more vibration

I don't have balance shafts on my car and I love it. It felt like a 25 HP boost the first time I romped on it after having them taken out.

Does the vibration cause anything weird to happen? Like say the knock sensor activating???

My advice, get rid of that piece of sh!t ASAP
it took out my timing belt

Scott Neville and I have removed our B Shafts this pass summer.

We both noticed a "little more" Engine Vibrations. Hard to tell "over the line". I consider it neglegeable

As for power; I got a NT and I noticed quite a bit more. Some say up to 30. I'd say about 15 to be conservative. Scott also agrees the added Vib is very neglegieable. He back up the "about 15 hp (He got a Turbo).

Oh, I forgot. I also helped Scotty Williams (London) to remove both of his B Shafts. I asked him what he tought about the Engine Vib. His reply was that he did not feel and differences. He did feel the addred power.

That might be because he got Original Motor Mounts and Scott Neville and I have "Filled Mounts"... Dono, all of my fillings are still intacts.

One more pros is the fact that the stupid Front B Shaft Belt is out of the equation. That little bugger has caused more that one T Belt failure. I call it a piece of mind.

Would I do it over??? Big Yé.

I'd probably have the Rotating Mass balanced if I'd be rebuilding the Bottom End. Not that the added Vib bugs me, but just to do it right.

Ghislain.

There has also been discussion about decreasing engine life when taking out the balance shafts. I talked to my mechanic and he told me on the skidoos equiped with balance shafts they take them out and it noticeably decreases engine life, up to 50%.

I asked people to describe the type of power gain, and the best description I got was you know how slow and luggish your car runs with the A/C on... well turn the A/C off and that is like removing your balance shafts.

JUST TAKE THEM OUT, i FELT MORE ASS HP FROM REMOVING THE BALANCE SHAFTS THAN GOING TO THE 16G.

Sorry about the caps

You should have the rotating mass balnced but most don't unless ytheir rebuilding the engine.

I've also taken off the lip on the flywheel and probally gained a few more hp.

That settles it, out they go!
Does anyone know what the kit costs and what is involved in the job, or some sites I can check for the procedure?

It's also worth mentioning that there were cars sold that had the 4G63 engine without the balance shafts from the factory.

[ November 19, 2001: Message edited by: Jeff Mitchell ]

about the worse thing i could imagine is it being rough on the crank bearings.

Well now I guess that makes sense.

Why would they build an engine and assemble it in a way that it needs 2 more shafts to keep everything balanced. Does this mean that they are sloppy with clearances when instaling the crank, rods and pistons, so they need these shafts to make up for it. I guess that would be silly.

The balance shafts are not meant to balance the rotating mass (crank, rods, pistons, etc.) of the engine. They are used to smooth out the power pulses inherent in a four cylinder engine. Here's why: From a monetary standpoint it would be cheaper to balance the engine without the shafts (less parts and machining). Even if it was meant to balance the rotating mass it would not get rid of the imbalance, it would just counteract it. Therefore it would still be out of balance but you wouldn't feel it in your seat. In other terms, the balance shafts cause a vibration in the block that cancels out the vibration caused by the rotating mass.
So, I would expect an increase in engine life mostly from an increase in oil supply to the crankshaft.
I'd like to get to the bottom of this one so if someone has good info on this, lets hear it. If you think I'm wrong, I'd like to know.
Thanks!

I too noticed a power difference after removing them BUT I am one of the few that noticed greater vibration at idle and at 3500-3700 RPM.

Scott, you mention that the shafts are there to remove harmonic sounds...Could these harmonic counds great fake knock? I have been plagued with phantom knock ever since I rebuild my head and removed the shafts. What do you think?

I definitely feel more vibration with them out, but Scott knows a hell of alot more about engines than I do, so take that for what it's worth.

Same here Peter. Somewere around 3500 to 3700 rpm but I consider it to be very negligeable.

Most ppls don't like to feel vib up their ass (Same here...) that is why (I think anyway) that Mitsu put them in our Beautifull Powerplant. Question of comfort. We, well most of us don't care about it (Eng vib that would be). We prefer taking them off in order to get a few extra ponies.

As for Engine life; In my case my car has 215 000km. How much life I'm expecting out of that Motor??? Put it this way an other 25 to 50 000mk would be good. I think I'll be able to reach it with them off, if not and it blows up tomorrow, big deal. It will give me the excuse to get a new one...

Now lets say you rebuild a Motor to a New condition (Your a power user). How many kms would you like that Engine to Last??? 50 000km would be good right??? Do you think it would last that long??? I'd say yes and probably more, maybe twice that much. I don't think than having removed the B Shafts would half the life of an Engine, remember my Engine has over 200 000km (It's a NT). How many K's has your Engine Scott??? My bet is that even a Turbo Engine won't be affected that much more compare to a NT.

I could go on and on about it. I'm convinced that removing the BS is a good thing if you are looking at the Power numbers. Relieability "might" be affected but not by half of the normal life of an Engine. It hat statement of mine is right that means that you Engine should last at least 100 000km...

Oh, Mitsu 2.6L Engine were the shits (Oil pump Chain tentionning related). I helped a Buddy of mine while he was replacing his into his stupid Van. He bought a Rebuild Unit. Both BS were removed by the Engine Rebuilder. You can buy a BS removal Kit from Crappy, Carquest and Napa for these Motor. We just have to make 0ur own or get one from a shop. Just sad we can't get it at the local part store. Not, you can make your oun. Anyway, if Engine Rebuilder remove BS out of the 2.6L they must know that it won't affect Engine life that much???

Ghislain.

This is interesting. What difference would it make if your motor has already been modified to handl more horsepower than usual? Is there any point where the balance shafts are NECESSARY? If not, hell, *I* want to remove mine!

I don't thnik so.

Nick Magor has between 625 and 650 (I don't remember excatly) of Dyno proven hp. His car is a Highly Modified 95. He uses it for Solo1 and has done a few 1/4 miles pass with it. That car has no B Shafts. I don't know if the Rotating Mass was Balanced but that give you some numbers to "work" with...

Ghislain.

I think shops like Extreme and Buschur say "you must get the enitre rotating mass blanced" just to protect their own asses when they sell the eliminator kit...which you don't need.

[ November 20, 2001: Message edited by: Vince Amato ]

The purpose of the balance shafts is to reduce second order vibrations. Balancing the crank assembly reduces first order vibrations. It is the first order vibrations that effect engine life and performance. Now the better the first order vibrations are controlled the less second order vibrations you will have. Second order vibrations do not hurt anything in the engine they are just annoying. Usually second order vibrations are hidden by using softer rubber engine mounts. That's why non-Talon 4G63 engines may not have balance shafts, because they are not performance cars. Now the Talon being a performance car and we all know the benefit of have solid mounts, DSM put in stiffer rubber engine mounts for better performance. Then to reduce the annoying second order vibrations they installed balance shafts. More expensive but better performance.

How hard is this to do? Who could possibly help me do it to my Talon?

my GTX has(had ) balance shafts, my elantra has balance shafts. They are not performance cars, they are family cars.....There goes your theory darryl try again.

[ November 20, 2001: Message edited by: Len Randall ]

Anyone?

Gates, I'm no wrench-man but I think it's just a case of locating the right belt and cutting it.
Have you got yourself a shop manual?

T

Len, just because those cars have balance shafts and they are not performance cars does not necessarily mean that my theory is in incorrect. There could be several reasons why those cars have 4G63 engines with balance shafts. You'll have to come up with a better reason then that.

Edward, I'm afraid that's not at all accurate. A balance shaft removal should really involve the removal of some kind of a shaft, dontcha think?

The procedure is described <A HREF="http://www.vfaq.com/mods/balance-shafts.html">here</A> and <A HREF="http://www.ecanfix.com/~mdhamilton/balanceshaft.html"> and here</A>

Jeff Mitchell

I'm contemplating having my B shafts removed when I do my timing belt as an experriment for my mechanic. I already printed out the appropriate literature for him to read. COnsidering parts for the elimination are not too expensive..i rather he practice on this engine rather than on my future (nicer) car. heh

Question is.... How long would it take a competant mechanic with all the proper equipment and tools to do it. These things are not covered under 'the book' so he has no clue how long it is going to take him or if he has enough time to do it.

http://www.ecanfix.com/~mdhamilton/balanceshaft.html

Thanks Mike!

Jeff,

I understand re: Removing the shafts tell me I'm out to lunch here. Why not just cut the belts? Seems to me to be an much simpler operation for the same result albeit, you still are carrying around the weight of the shafts but they are not being rotated by the crank. It's the belts that cause the problem of breaking and taking out the timming belt when they go.

The rear balance shaft is on the oil pump. If you cut the b-belt, the rear shaft will still spin but now the vibration will be worse because you have this off balance shaft spinning. I know, I had a b-belt break but lucky it didn't take the t-belt out. Make sure your kit uses the Mitsu stub shaft with the oil groove or you may kill your oil pump. If you make serious power, push your car hard, race.. what ever. Its best to get the rear shaft machined to a normal looking shaft and re-install. This way the oil pump is on a shaft supported at both ends instead of a cantileverd shaft. This is strongest, safest way. You can remove the front b-shaft or leave it in as it won't spin. NO, mine is not done.

OK, I did mine ala Mike Hamilton (see his web page)and it worked out amazing. I cut my oil pump shaft, rotated my bearings so the oil holes were plugged, and used a frost plug to seal the timing cover. My car is much more responsive, and I'd say it upped its power a bit. I would recomment (if I could do it again with the motor out) to get the engine externally balanced after the shafts were removed, just to be on the safe side.

Nino,
Can't the gear be removed out of the rear balance shaft so that it dosen't get spun by the pump?Then re-install the assembly the way it was only without the gear?

T

Edward, no can do. The b-shaft and the oil pump shaft are the same shaft. There's only one gear that drives both.

Jeemy I would not recomend having a mechanic do this for you. They are going to charge you a lot of money to do it and I am willing to bet they will screw I up if they haven't done it before. Then you will be screwed since you told them to do it and they were onle following the customers instructions.


And you can leave the front one in and just cut the belt but the back one is part of the oil pump so you have to cut the shaft and plug the hole.

I was luckey enough to have Mike H help me do mine....we did it this way.

[ November 25, 2001: Message edited by: Vince Amato ]

So is there any proof either way whether this could increase knock (phantom knock)?.

If the knock sensor is sensitive enough to hear the lifters tick, even slightly, couldn't the harmonic frequencies produced by a balance-shaftless engine set it off as well?

I have my doubts that the knock sensor could pick up harmonics....the knock sensor is a microphone(stethoscope) that converts sound vibrations to electrical signals. Valves opening and closing, or injectors pulsing on and off or the sparc plugs firing doesnt affect timing. Lifter tick is a whole different scenario cause its alot louder than any of the prev scenarios with the exception of the injectors which are actually mounting on the intake which is isolated from the engine block by a cardboard gasket. This is the same theory as wrapping the knock sensor with teflon tape and making sure not to overtorque it. The teflon is an insulator and will deaden the sound abit and is especially effective on higher frequencies.


Most knock problems can be fixxed by zip tie'ing the knock sensor to the fire wall in any case...LOL

[ November 28, 2001: Message edited by: Len Randall ]

On thing that wasn't clear about balance shaft removal was the added noise.

The technical manual calls the balance shafts silent shafts!

The engine screams between 3600-4200 rpm where the major resonances occur.

Around 5500-7000 is another node that is loud.

Added vibration? A little - you will notice if your dash is loose.

Added power? Not sure about that one.

Added security in knowing that your non-existing b-belt will never take out your engine?
Priceless. Well at least $2500 worth

Recommendation?
In a 1G AWD 3700 rpm is around 135-140kph
If you do alot of hiway driving around this speed the resonances are annoying. Not quite honda annoying, but bothersome nonetheless.