Shaving Balance Shaft

[CoopsCoupe]

Just got my Balance Shaft from the shop and It looks great. Not perfect but I cut the head off and the weight off the side to help support the oil pump better for reving. I also had it balanced. Took a while but it is even. I really believe in this method. NOt a fan of using the Stub shaft but It does work great. I have just had this in my mind for awhile now, and I decided to do it myself after talking to some pro's with our cars... My shop did a great job, glad I went this route, I just have peace of mind. One less worry for my dsm.. Im getting pictures soon.

 

[cruisintalonawd]

how much did that cost you???

 

[CoopsCoupe]

Well, I bought new materials and it ran me about a 100 for the parts and labor.... I think I made out ### it took them a long time to do it. Very time consuming work.

 

[Defiant]

So you're re-installing the hazard of a failed balance shaft bearing, the primary reason for removing them? You still have a plain bearing running at twice crankshaft RPM, but now without the benefit of canceling secondary crankshaft vibration.

 

[CoopsCoupe]

The Vibration is gone. The shaft is shaved and Balanced. Magnus runs the same saft. They even sell it the way I made it. I have a new bearin installed and I bought a brand new one from Mits. So where amI getting vibration? Im supportting my oil pump better so that I may rev higher. Im taking every precaution because Our cars are not known for durability. Im trying to change that... I alredy have the left blocked off and the right rear is new. The oil pump is also has deburred gears. I have talked to top racer, and I am going the right path.... If you havn't ever thought about it or tried it, you should. I also have a Fluidampr on the crank......

 

[Defiant]

Living with the minor, and largely mount-absorbed vibration is one thing, and isn't my point. What is my point is that, you still have that shaft running in plain bearings oiled by a spinning galley. When the motor's running 6K, that shaft is spinning 12K, and this phenomenon is probably what starves the center balance shaft bearing on the rear shaft; all the more so for those who imagine some benefit in winding a 4G63 to 8K and even higher.

 

[CoopsCoupe]

Im not an expert on it. Im just going with what people and magnus had said. I can see the logic in it. I'll be doing checks on it for the first year like every two weeks. I also have a stroker so Im not going to be reving as high as 8. I wish, but no.... I've seen the left front bs get block causing the oil pressure to raise up slightly.... So if I have done my math right, I wont be starving the Shafft at all due to the built up oil pressure behind it. It really should level it out. Awhile back We blocked off the left shaft and kept the right in. There is a reason for this madness..... We wanted to see the oil pressure with autometer aftermarket gauge, and see a stock verus what we did...stock was about 8 psi lower and we have seen people with the stub saft go as high as 14 psi more.So we like the looks of the pressure at 8 psi more. I was and still running my squirters as well. As for the bearing, OEM mitsu, I'll check it every two weeks. Get up in there and see how it is working and if I don't like it. A stubby shafting I will go..... Just trying methods that have shown through over test..... Thanks for the concern.

 

[JamiesTSI]

I have been doing the modified rear balance shaft for some time now. The motors I have done all have one in them, including the 2.4L thats on the motor stand now. The oil pumps I have seen all had to have the stub shaft hammered out. I have an old oil pump that I will take to work and cut in half with the band saw. I'll post up some pics to give everybody an idea of what I am talking about.

 

[CoopsCoupe]

Im glad that there is more people that have seen and know about the Bs mod.... JMGSX had pm'd me about RRE doing it but he could not post in this Section so I cut and copy his Messege.....

"I can't post in the forum you posted in but I wanted to let you know that RRE has been doing this for a while with no ill effects that I know of. When I was there a year ago, Robert explained then showed it to me. I intend on doing the same when I get mine built. Just wanted to give you some more data.

Justin"

Thanks alot Justin. I kinda wish I would have had all this info from you guys before I went and tested it.. But at least i know first hand how it can help the engine and now know that there is more people, exspecially raceshops that are well known doing it as well... Thanks....

 

[JamiesTSI]

This is what I see when running a stub shaft. Does this happen all the time, I don't know. At what time does this happen, again I don't know. What I do know is when I take apart a oil pump (with balance shaft) that has 100,000+ miles on it. I don't have to hammer the balance shaft out.

 

[CoopsCoupe]

That is bad.. Yeah, I have heard the stub shaft does make a lasting impression on the pump. Didn't know it got stuck. Thats why im doing this mod. Nice pics by the way. I can't get my camera to work. Kinda makes me mad. I love how it looks. I didn't shave the whole shaft. Just cut the weight off and balanced it. NICE PICS THOUGH

 

[dsm-onster]

Yea, I thought that b shaft bearing failure at high engine rpm is due to the b shaft being unbalanced--albeit purposefully-- in the first place. The question I guess really is: How much speed can a balanced straight shaft see before the minute balance imperfections cause the bearings to fail? Since beaing failure really only can surface from vibration, surface imperfection, or rub from a dry start.

I don't know how much (less) engineering goes into a B shaft bearing. But, I wonder if the speed is enough to wipe the bearing dry in the first place where the shaft is cut to balance. Good old motor oil is amazing stuff. If you can take a turbo journal bearing to 150,000 rpms without recourse, would a balanced cut balance shaft handle 16k-20K fine?

 

[Street Surgeon]

Well, I bought new materials and it ran me about a 100 for the parts and labor.... I think I made out ### it took them a long time to do it. Very time consuming work.

I had considered this method as well but ended up going with the tried and true stub shaft, there may be some stub shafts that get a lil' nasty in the oil pump but there are waaaay more spun balance shaft bearing related failures!

However if this is the method that you choose, know that you can buy Magnus' billet balance shaft elimination kit that features their own billet version of a turned down balance shaft. Except it's a CNC'd billet piece and not some turned down shaft. Also, it's 75 bucks.

Magnus Motorsports - DSM/Mitsu Engines

 

[kittay]

Did you just shave the one and remove the other? That's what I was going to do on mine, but waiting for the machinist, I have no patience and a balance shaft removal.. so idk..

 

[Strm Trpr]

the majority of oil pump failures come from a) over tightened T-Belt, or the use of the non oil galley stubby shaft seen here. 4G63 4G63T 2.0 4G64 2.0 Balance Shaft Eliminator Kit Mitsubishi and Hyundai
This is the mitsu stubby shaft. http://www.vfaq.com/mods/balance-shafts.html

I recently helped a friend do a BSE, and we found his inner most front balance shaft bearing out of it's bore, and split in half.
So, his front b-shaft was wallowing out the bore for the bearing.
Made for an easy bearing replacement...

 

[CoopsCoupe]

I like what I did. Im stroking it anyway so Its not like im going to rev it to the moon. Just be patient because that is a long process to do. I didn't know that Magnus sold them. That sux.. But I still did it myself and I feel like I did something for my engine.. Anyway, Im going to be trying it soon. Im going to tare it down and look inside ever 4k miles or so.

 

[Strm Trpr]

This is what I see when running a stub shaft. Does this happen all the time, I don't know. At what time does this happen, again I don't know. What I do know is when I take apart a oil pump (with balance shaft) that has 100,000+ miles on it. I don't have to hammer the balance shaft out.

The scoring you see in these pics aren't even the correct bore for stubby shaft.
These pictures indicate that the T-Belt was too tight and pulled on oil pump sprocket and wallowed out the bore.
This is a perfect indication of why it's so important to make sure your T-Belt tension is within spec of .150" - .180".

There is absolutely no way the stubby shaft had anything to do with the damage in those oil pumps.
Now, if those pictures showed the x-section thru where the stubby shaft rode, and I saw scoring there, then I would be totally wrong.

This is totally over kill, and not necessary on a street car.
Knock yourself out tearing it down every 4k miles.......

***I'm referring to these pics http://www.dsmtuners.com/forums/151458050-post10.html***
***Show me the oil pump cover. That's where the stubby shaft bore is, if it has damage like the oil pump bore, then I'm totally wrong.***

 

[JamiesTSI]

Yes you are correct I said the wrong item. I meant to say the oil pump shaft needs to be hammered out on oil pumps that I've seen with the stub shaft. Sorry for the miss communication.

I personally feel this is a worth while item to do(modifying the rear balance shft) and will continue to do so with the engines I put together.

 

[Strm Trpr]

AMS makes them and sells them for $300.
Automoto Sports Copyright&copy AMS 2006
I have 4 rear shafts sitting in my garage.
Perhaps, I can make some kits too and sell them for half price $$$.

 

[Street Surgeon]

AMS makes them and sells them for $300.
Automoto Sports Copyright&copy AMS 2006
I have 4 rear shafts sitting in my garage.
Perhaps, I can make some kits too and sell them for half price $$$.

Well.... That would still be 2x more than the billet magnus bse kit that I posted earlier in the thread

 

[Cesar]

i thought the stubby shaft was an oem piece equipped in many mirages and such.

it can't be that unreliable.

besides the 4g63 is very popular, why not just design an oil pump with the elimination in mind? people replace pums all kinds

 

[92awddsm]

Has anyone considered the fact that chances are, the rear bs bearing journals are probably not even in alignment with the bore of the oil pump shaft? They would be if the oil pump housing was machined along with bs bearing journals but in real life, that doesnt happen. Core shift, tool bit sharpness, temp at which parts were machined, aluminum cover on cast block, different manufacturers tolerances, etc all affect bs bearing alignment. With a replacement pump, chances of perfect alignment are about the same as finding a reliable 1g for $100.

And I have been running a stub shaft for over 8 yrs with no ill effects. I will continue to run a stub on my current build also.

 

[CoopsCoupe]

Actually I found a 1g engine for 100 and 50 for the engine.. So that comment is pointless to me. That engine that I bough ran fine in the car and is the engine I am building now. The tranny shifts great. it is in my friends car right now until John is done with his.... But anyway, Im still glad that I did it. and now with Magnus and AMS backing my idea. I have no fear. They know what the hell there doing. Thats for sure.

 

[dsm-onster]

Has anyone considered the fact that chances are, the rear bs bearing journals are probably not even in alignment with the bore of the oil pump shaft? They would be if the oil pump housing was machined along with bs bearing journals but in real life, that doesnt happen. Core shift, tool bit sharpness, temp at which parts were machined, aluminum cover on cast block, different manufacturers tolerances, etc all affect bs bearing alignment. With a replacement pump, chances of perfect alignment are about the same as finding a reliable 1g for $100.

And I have been running a stub shaft for over 8 yrs with no ill effects. I will continue to run a stub on my current build also.

I am so completely not negating this possibility. I've just never had to replace a 4gXX pump .

 

[TurboAnything]

My engine guy here in chicago the same guy that dose AMSs motors still dose this BSE mod. I have run it in 2 6-bolt builds with nothing but good things from it. I like the lower oil pressure at startup mainly.