Rotor Pack Failure..ouch (Lots of pics)

Suthrns_Finest

Registered User
I heard a little noise from the supercharger, drove it for a couple of days to and from work anyways. I was going to fix it today, but the MPX seized up on me on tuesday and finally got to taking it off the bird and took it apart. WOW, the damn rotor pack completely freaking broke apart.

The case seems okay, besides a little gouging and scratches, but i want opinions on whether i should buy a new mpx case or continue to use this one. Let me know.. Thanks









Broken Rotor Pack






 
I think the case will be fine. I would take some fine grit sand paper and lightly go over it making sure there is no build up.
 
WOW, that is ... "exciting".

The rotor pack looks like a stock 94-95 pack, correct? Was any work done to it? Original bearings? I have never seen anything like that before. Can you tell if the rotor bearings are seized or "gritty"?

Also, are there any signs of ingesting debris? Are your throttle blade screws still there? ;)
 
Au contraire. The case is basically junk. You can see where aluminum has been drawn up either from the rotors or from the case itself and re-deposited in lumps in various areas. These lumps would have to be completely removed or you'll just eat up the next set of rotors. Removal of the lumps is most likely going to result in gouges etc. which is going to significantly reduce the efficiency of the blower.

I mean, you can probably run it, I wouldn't hold out any hopes for longevity or performance.
 
Au contraire. The case is basically junk. You can see where aluminum has been drawn up either from the rotors or from the case itself and re-deposited in lumps in various areas. These lumps would have to be completely removed or you'll just eat up the next set of rotors. Removal of the lumps is most likely going to result in gouges etc. which is going to significantly reduce the efficiency of the blower.

I mean, you can probably run it, I wouldn't hold out any hopes for longevity or performance.

Yeah I noticed it was pretty bad after I zoomed in on my phone.
 
I have had the MPX for over 3 years and has performed like a champ. I bought it used, but the guy i got it from said they were a low mile rotor pack. When i first got everything, it was nice and clean and everything was tight, no play in rotors or anything. I put maybe 15,000 on the MPX while i have had it. It was only overdriven 15%. As far as any debris, no. The screws on the blade for the throttle and such are all there and intact. When i first heard the noise in the charger, i took off the top and inspected the rotors and the right one was loose at the plate. I suspected the rotor bearing at the plate was faltering, i just thought i could get away with a couple more days until i was off to fix it.lol The only thing i can think is the new FMIC tubes i fabbed up. I cut them and got them welded up and installed them. If anything, there could of been a slight amount of aluminum dust from me cutting them and not throughly making sure they were free of debiris. But hard to believe that would be the reason for rotor plate bearing failure.
 
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Au contraire. The case is basically junk. You can see where aluminum has been drawn up either from the rotors or from the case itself and re-deposited in lumps in various areas. These lumps would have to be completely removed or you'll just eat up the next set of rotors. Removal of the lumps is most likely going to result in gouges etc. which is going to significantly reduce the efficiency of the blower.

I mean, you can probably run it, I wouldn't hold out any hopes for longevity or performance.

Well, a new case is $800, right? So there's some financial room there to attempt a repair. I wonder if MP or ESM has cutters that can get the bores straight? If so, the case could be coated inside to smooth out the pits and restore some (certainly not ALL) of the proper sealing.

Suthrns_Finest said:
If anything, there could of been a slight amount of aluminum dust from me cutting them and not throughly making sure they were free of debiris. But hard to believe that would be the reason for rotor plate bearing failure.

Yeah, that sounds too small to cause this amount of damage. (In my amateur opinion.)

Suthrns_Finest said:
I suspected the rotor bearing at the plate was faltering, i just thought i could get away with a couple more days until i was off to fix it.lol.

Apparently not (haha).
 
yup, thats my fear with these high mileage rotors. And od reduces the amount they last. New mpx are like 600 so i would just get another one, that case is pretty bad. How big is the Tb?
 
I'm thinking that case is wasted...

MP might be able to fix it, but I bet that would be expensive too. Assuming the tolerances came out right, it might be interesting to see if a coated case would lead to better performance of the MPX. Then again, you have the eventual coating flaking problem.
 

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Is it just me

Is it just me or does it seem like the MPX's are having more noticeable failures than all the other M90 superchargers out there.

I only say that because my old worn out MPIII I have, seems to be doing great, but then you have Kevin running some rediculous OD on his MPX, and I don't think I have heard of him destroying a rotor pack, so is it just a bad set of bearings.

Although John Ludorph, I think went through 2 MPX's in a very short time, both destroying the rotors!

I don't know if there is a common theme here or not.

Smitty
 
Is it just me or does it seem like the MPX's are having more noticeable failures than all the other M90 superchargers out there.

I only say that because my old worn out MPIII I have, seems to be doing great, but then you have Kevin running some rediculous OD on his MPX, and I don't think I have heard of him destroying a rotor pack, so is it just a bad set of bearings.

Although John Ludorph, I think went through 2 MPX's in a very short time, both destroying the rotors!

I don't know if there is a common theme here or not.

Smitty

Nope Chris has had MPIII failures and so did I. Its not the case, its the rotor pack. The first batch of MPXs were tight for better performance. But with so many variables related with rotor pack condition Charles increased the bore.

There is blower flex at extreme conditions, The rotors usually just wack the bore and scratches it. A bad set of rotors will just seal the deal.
 
I noticed that the OEM couplers are spring loaded.

Could these aftermarket solid couplers cause more stress on the rotor packs?

I'm guessing but was the spring there to allow a bit of play so it wasn't so abrupt upon first spin?

EDIT: Ricardo, I just saw your post....... Hmmmm, maybe there is something to it
 
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When i first heard the noise in the charger, i took off the top and inspected the rotors and the right one was loose at the plate.

Drivers side?

I'm wondering if the case is the problem...you just don't hear about this happening with stock sc's - even overdriven. Of course, it's not such a big deal unless you paid around $1000 for the ruined part!
 
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