Well, ring me up for a MPX rotor failure

[mywhite89]

So, last week I was working out some driveability issues with the car. Putt-sing around town, feeling pretty good that I had it fixed, and my blower started making some nasty noises. Luckily I was close to a tractor trailer late night repair facility and borrowed a couple wrenches to get my blower belt off.

Drove it home, and I gotta say, this car is so damned quiet without the blower belt on. It was almost a sigh of relief because the engine purrs along so smooth.

Anyways, I took the blower off last night and the case is ruined, rotors are ruined. MPX DID NOT FAIL JUST FOR CLARIFICATION. Rear bearings are intact just fine. One of my rotors has way too much side to side movement, whatever bearing holds that rotor is junk. So once again, I have a ruined blower, ruined rotors, and I'm kinda pissed.

Charles is a great guy to do business with and has offered to help me out on buying a new case. Just kinda venting on what to do next. I'm starting to think turbo or whipple. I don't know if I can fathum another M90 with my luck, and I hate to buy the same thing twice like this. The rotors came out of a blower that had been assembled by Magnum powers a while back, so I figured they were rebuilt. Turns out, thats not the case typically according to him. I wish I would have known this before, I thought those things were ready to go.

Chris

[ricardoa1]

So the failure was on th front bearing plate? OR was it on one of the rear bearings.

[rzimmerl]

That sucks to hear. Finding a good rotor pack is hard to find. They are NOT rebuilt when MP does their builds, and I think everyone assumes he does. MP should state that information on their site. High Speed Lab is the only company I know of that does a rotor pack rebuild. I have seen 2 rotor packs fail, both in which the shaft moved on the front bearing (1 causing contact with the rear of the case and the other contacted the front bearing plate), not the rear bearings failing. More than likely we are exeeding the bearings rated RPM's, which could be cause of the failures.

[mywhite89]

Front bearing in the spacer plate is what failed.

Ryan, the bearings not being able to hold up for long is what I am afraid of also. I've already had a rear bearing failure at just over 1,000 miles that trashed a blower earlier this year

[frdlvr30]

Originally Posted by mywhite89

Front bearing in the spacer plate is what failed.

Ryan, the bearings not being able to hold up for long is what I am afraid of also. I've already had a rear bearing failure at just over 1,000 miles that trashed a blower. On the other hand, who knows how many miles those rotors have on them.

That really sucks. Guess there is a lesson for everyone to learn from this...

[mywhite89]

at least its a quick job to replace if thats what I decide. I didn't screw up the case too bad, maybe i'll just slap rotors in it for the time being since I still have 1 good set left. I just like it to run if I need it for alternate transportation.

[ricardoa1]

Your title of the post should be changed, no reason to discredit the MPX if it did not fail. Mine on the other hand, is not doing too well in the rear bearing area. Charles said he would warranty it. I have not had the pleasure to take it apart again. But I did have play in the right rear one and now makes lots of rattling noises. The bore walls were scraped by the rotor tips. I ran it at the shootout like this, and was planing sending it to charles for inspection and warranty if needed.

Wade will give you an option of getting higher speed bearings on the bearing plate when you have him rebuild the rotor pack.

[rzimmerl]

Ya, I agree with changing the title of the post since the MPx case had nothing to really attribute to the failure. Post some pics of the damage if you can. I was able to reuse the 2 NON MPx cases I had when the rotor packs failed.

I think it would be wise for Charles to post something about rotor rebuilding, so that if something like this happens people don't say "those MPx's are failing, I'm never gonna buy one". Think of it this way with the MPx, its a new case, new rear rotor bearings, most likely a rebuilt snout, but the same ole rotor pack thats never been touched.

[kenewagner]

Originally Posted by ricardoa1

Your title of the post should be changed, no reason to discredit the MPX if it did not fail. Mine on the other hand, is not doing too well in the rear bearing area. Charles said he would warranty it. I have not had the pleasure to take it apart again. But I did have play in the right rear one and now makes lots of rattling noises. The bore walls were scraped by the rotor tips. I ran it at the shootout like this, and was planing sending it to charles for inspection and warranty if needed.

Wade will give you an option of getting higher speed bearings on the bearing plate when you have him rebuild the rotor pack.

Just a question, Since most MPX owners are overdriving way past what the stock M90 is driven, it would make sense that the bearings are not up to the task of the increased speed. Also would not the extra heat generated by the increased heat, decrease clearances between rotors and case? Add that all up and will there be more failures? I also wonder Ricardo if the longer rotors in your blower flex do to the increase length? Just some thoughts on the subject.

Ken

[ricardoa1]

Originally Posted by kenewagner

Just a question, Since most MPX owners are overdriving way past what the stock M90 is driven, it would make sense that the bearings are not up to the task of the increased speed. Also would not the extra heat generated by the increased heat, decrease clearances between rotors and case? Add that all up and will there be more failures? I also wonder Ricardo if the longer rotors in your blower flex do to the increase length? Just some thoughts on the subject.

Ken

On mine the left side is nice an tight, the right is a little loose. i know you had an exception with the rear bearing on your jag blower but. But most JAg blowers that Wade has rebuilt has similar needle bearings as the M90. I asked him today, it was by chance that he called me up today to ask me how the season went with my set up. I gave him my bad news and didnt say much after that.

[XR7 Dave]

John Ludorf and I lost an MPX due to worn bearings. Then I installed a brand new set of rotors into a brand new MPX case. That blower was QUIET and made significantly more boost than the other one. Until it seized up also after about 8 dyno pulls.

I don't want to put any scare into anyone either, but there is a real issue here that people need to be aware of. I've talked with Charles about the root cause and a solution but I'm not sure that there is anything that can be done. If rotor bearing packs are bad on average, does that mean that the cases should be made with extra clearance to anticipate what will happen with worn rotor packs? Seems kind of counter productive to me.

In any case, I had a worn rotor failure and a new rotor failure all in the space of 24 hrs.

[Mike8675309]

Is it possible to find a way for folks to check their rotor pack? Some way of checking for required go/no go tolerance? While many may not be happy to deal with the added expense of rebuilding the rotor pack, I can't imagine they would prefer the alternative of trashing a case, or simply not installing their MPX.

[rzimmerl]

Does any one have the front rotor bearing number to do some research on? Intereted to see the bearing RPM capacity, working heat range, load rating, etc...

Here's another question, of the MPx's failed what has been the % OD used?

I've ran with a worn pack (there were marks in the rotors from hitting the early case they came from) and a low mileage set at 15% OD running fine. Also when swapping those packs, I noticed that the rear bearing grease had disspated all over the case. My guess is that the heat range for the grease had been exceeded.

[frdlvr30]

Originally Posted by XR7 Dave

John Ludorf and I lost an MPX due to worn bearings. Then I installed a brand new set of rotors into a brand new MPX case. That blower was QUIET and made significantly more boost than the other one. Until it seized up also after about 8 dyno pulls.

I don't want to put any scare into anyone either, but there is a real issue here that people need to be aware of. I've talked with Charles about the root cause and a solution but I'm not sure that there is anything that can be done. If rotor bearing packs are bad on average, does that mean that the cases should be made with extra clearance to anticipate what will happen with worn rotor packs? Seems kind of counter productive to me.

In any case, I had a worn rotor failure and a new rotor failure all in the space of 24 hrs.

Why haven't you mentioned this before?? Seems like a very important issue with all the MPX's hitting the streets lately.....

[XR7 Dave]

Originally Posted by frdlvr30

Why haven't you mentioned this before?? Seems like a very important issue with all the MPX's hitting the streets lately.....

Mainly because it only happened just prior to the SC Shootout and we did not have any word back from Charles as to why they failed until a couple days ago. Add to that the fact that I get railed any time I say anything that might be construed as negative towards an M90, I am therefore rather careful what I say and when.

I don't know why the new rotor pack failed, Charles thought it might have been defective...