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Keep the balance shaft?!?!??

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drcolt

20+ Year Contributor
76
12
Jun 27, 2003
Toronto, ON_Canada
I am in the middle of changing cams to performance cams and I figured to replace the timing belt and all seals and pulleys and waterpump, etc....... remove balance shaft. or not. I dont know the history of the motor I have. All I know is the donor car had over 530K kms on it.
I then recalled this was talked about a few years back, found this site, http://www.jackstransmissions.com/pages/keep-your-balance-shafts


That article makes a lot of sense. I believe BS failure is improper maintenance. I do have the kit for deleting, but now I am thinking I might just keep them. I am not after big hp. I do want a nice driving motor, although there is nothing smooth about the colt!

This should be a good read for new dsm owners.
There have been nissans that have had issues with knock at high rpms when balance shafts have been removed.
Porsche makes their motors with BS, as well as many other manufacturers of large displacement 4 bangers.
 
The issue with the balance shafts in the engine is when the balance shaft belt or one of the balance shaft pulleys breaks and takes out a healthy engines timing belt, or the balance shaft bearing spins and seizes up your oil pump and that takes out a healthy engines time belt.
They are a good concept in theory, but unless the system is functioning perfectly, they are just another possible way to take out the timing belt and ruining an engine.
 
If I was looking for comfortable daily driver I would leave them in. My current gsx has them out. When combined with poly mounts all around it gets loud and vibrates a bunch. Just gotten used to it over the years. Something to think about if your not going for high hp and planning on driving it frequently.
 
Hate those shafts haha. My gst motor was a health 240k 350hp beast till that stupid belt took it out. The belt was even newer and still shredded and took out my timing belt and blew the bottom end. Just about ripped cyl four from the rest of the block haha was crazy. If your stock hp and don't race it's probably fine to keep. But if it was me I would delete all of my motors are now LOL. ;)
 
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I hate balance shafts but for a mostly stock daily driver most ppl keep them, every car I have had with them I have always itched till they were remove but then again I have had hard mounts on all mine even my family cars I think its more of a preference.
 
I think the two biggest consensuses around here are either keep them (and of course proper maintenance on the belt), or remove them the proper way with a good quality elim. kit.

Personally I would advise for you to keep them. It helps even out the natural frequencies especially in higher RPM ranges.
 
I have the motor out right now. ( When i did the swap I just took the running motor out of the donor dsm and swapped it in to see if all wiring and mounts work out)
So, It started with a bad harmonic balancer, and a rear main seal leak. I figure to just pull the motor out and clean it all up. Then I figured , while its out, may as well go deeper, since in the colt there isnt luxury of space like in a dsm. So I bought cams, and water pump, timing belt kit, gasket kit, balance elimination kit. But no sproket spacer! I forgot that detail. Looking online to see whether or not i can just leave the belt sproket, I came accross Jacks website.
BTW, do I need to replace the balance sprocket with a spacer, or can I leave it. I dont see why I can't?
I Have mixed feelings about the BS.
My goal with this car is 300ish hp, It is fwd, so no point going for more. Its is rarely driven, but when I drive it, it gets a little beating.
 
This is one of those topics that is difficult to convince either side of the fence. I am a proponent of keeping the balance shafts. While I understand why people delete them, I wouldn't even consider it unless the engine was receiving a rebuild. It boggles my mind that many companies offer balance shaft delete kits with timing setups. I have had zero balance shaft-related failures in my time with DSM's. I would say that I drive my cars pretty hard compared to most owners, but they also receive an equivalent maintenance schedule. The two likely failures tend to be belts and bearings. Obviously, keeping up on timing service is key. Gates offers a Kevlar balance shaft belt to reduce chances of a belt failure. Changing the balance belt tensioner with proper tension is also key. As far as bearing failures, I would bet that if other bearings were inspected, signs of severe wear would also be present. As ceedawg suggested, the AMS and GSC balance shaft offerings are great alternatives.
 
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I
I am in the middle of changing cams to performance cams and I figured to replace the timing belt and all seals and pulleys and waterpump, etc....... remove balance shaft. or not. I dont know the history of the motor I have. All I know is the donor car had over 530K kms on it.
I then recalled this was talked about a few years back, found this site, http://www.jackstransmissions.com/pages/keep-your-balance-shafts


That article makes a lot of sense. I believe BS failure is improper maintenance. I do have the kit for deleting, but now I am thinking I might just keep them. I am not after big hp. I do want a nice driving motor, although there is nothing smooth about the colt!

This should be a good read for new dsm owners.
There have been nissans that have had issues with knock at high rpms when balance shafts have been removed.
Porsche makes their motors with BS, as well as many other manufacturers of large displacement 4 bangers.


I left mine in, just replaced everything and used a kevlar belt. But then my car is a street car, and I don't rev to 7k often. If it's more of a race car/weekend warrior or you will be revving it high a lot, delete it. If it will still see decent street use and not revving to 8k+ keep it. Just my two cents.
 
I have the motor out right now. ( When i did the swap I just took the running motor out of the donor dsm and swapped it in to see if all wiring and mounts work out)
So, It started with a bad harmonic balancer, and a rear main seal leak. I figure to just pull the motor out and clean it all up. Then I figured , while its out, may as well go deeper, since in the colt there isnt luxury of space like in a dsm. So I bought cams, and water pump, timing belt kit, gasket kit, balance elimination kit. But no sproket spacer! I forgot that detail. Looking online to see whether or not i can just leave the belt sproket, I came accross Jacks website.
BTW, do I need to replace the balance sprocket with a spacer, or can I leave it. I dont see why I can't?
I Have mixed feelings about the BS.
My goal with this car is 300ish hp, It is fwd, so no point going for more. Its is rarely driven, but when I drive it, it gets a little beating.
I'll answer your sprocket/spacer question. Yes you can just use the balance shaft sprocket as a spacer. As far as BS delete. like what has been stated it's more on what you want to do, me personally. I delete don't mine, I've seen a balance shaft bearing completely break off and fall into the oil pan while the shaft kept spinning and grinding off a bit of the block and put shavings in the oil. This was on a stock GS-T as well not my GSX. But if you are willing to do the maintenance with it go ahead, the annoying part would be aligning the oil port from the bearing to the port on the block when putting in the bearings. Hope this helps.
 
This is a dead horse that has been beaten since tuners started modifying these cars. :beatentodeath:

I still have mine, to help the case I've installed a Gates kevlar BS belt so hopefully it doesn't break and I check it every year. I feel like a lot of the issues that stem from the BS breaking are people ignoring it, since the FSM recommend a 60k mile service they don't bother to look at it with an "out of site, out of mind" mentality. Nothing you can do about a BS bearing spinning though, that's just unlucky.

Here's a good read if you've got a few minutes to kill from a reputable DSM shop. http://www.jackstransmissions.com/pages/keep-your-balance-shafts

I had Jackson Automotive Machine (JAM) build a 2.3L motor and they also REFUSED to build it unless I retained the BS's because of the additional engine harmonics created by a stroker motor.
 
I changed mine every year with Oem parts and it still failed. So you never know things happen. That Motor would still be running if it wasn't for that. My cars are always properly maintained especially when in race session.
 
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I'm of the opinion you should absolutely keep balance shafts. The above jacks transmissions link lays it out. I'm studying mechanical engineering and there is an entire class dedicated to vibrations. Vibrations lower the life expectancy of all machines.
 
I remember there was a discussion about this and pretty much everybody was calling Jack stupid , youll see the thread if you google it. I know im gonna delete mine , theyre still there right now but once the motor is out, theyll be deleted .
 
I had a balance shaft bearing fail/seize and take out my all stock motor about 2 years ago. The car is rarely driven hard and/or raced. Everything on the timing belt side of the motor was changed out approximately 6 months before it happened and the car has always had the timing belts replaced at 50K mile intervals (owned car since 1991). When I had the motor rebuilt by a local DSM expert in the Indianapolis area, we eliminated the BS shafts. As far as engine vibrations/harmonics go, I can't even really tell a difference and I drive the car 75 miles everyday for work.
 
maybe mitsubishi as an automaker could have saved a couple billion dollars leaving them off every 4 cylinder they use them on.
I never removed 400 dollars in moving parts "that do nothin" haha

I love using balance shafts. I have not seen a failure and I spin my engines to 9000. I do nitride shafts when I send cranks out. I dont care if other people dont run them. actually I recommend the average mechanic to take them out.
 
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Honestly its really up to you but i wouldnt take my chances leaving them on. If they fail your whole motor gonna go with it too, thats a big risk to take when you think about it. Jack build transmission , youre listening to a guy that barely build engines, ask STM , JNZ and other reputable shop and see what theyll say .
I hate to link you to their site LOL but read this and think again
http://www.dsmtalk.com/forums/showthread.php?t=239850
 
I could be wrong... but I believe the Mitsubishi Siruis engine platform (4g6x family) started out as a 1.6L. That version of the engine did not have balance shafts. However, when they bumped the displacement up to 2.0L, there was a noticeable increase in NVH which led to implementation of the balance shafts to counter that issue for people buying car with those engines (hard to sell cars if you feel vibrations all over the place). That would explain the comment above about leaving balance shafts for a stroker motor (even more displacement). That is why you can perform that "mod" using factory Mitsubishi parts... you are effectively using the parts found in the 1.6L enigne.

Like I said, I could be completely wrong because I am not an expert. It honestly seems that the whole balance shaft debate is really a matter of preference for the individual.
 
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