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V6Sprout
10-08-2007, 11:37 AM
OK so my blower rattles, seems to work just fine though, only really rattles at idle, so I figured it was the coupler. I put a piece of wood to each section of the blower and determined teh noise was indeed coming from the snout area. The blower was recently rebuilt and rattled from day one. I never rant he blower previously, I just used it to get rebuilt so no down time.

Well I finally got my hands on a 94-95 case soI decided to swap the guts from my blower to the new case. I get the blower apart and there are many scratches on the inside of the case, and I mean a LOT, but the rotors look almost new. What was really weird was when I pulled the snout off the two gears looked as though they were RUSTY, they had that rust texture but it was a dark black color probably due to the blower oil. The oil looked a rusty color inside the case but was black when poured out, it was recent replaced too, a few hundred miles ago literally.

On the inside of the rotor pack against the face plate, there was some black goo, kind of looked like rtv that I think was making the rotors not spin as smooth, but I cleaned it all up, cleaned off the gears with a wire wheel and cleaned out the rotor pack real good and dropped it in the 95 case and put her back together. My old blower had a solid coupler as well.

Well the new blower is installed and running and it still rattles. I havn't gotten into full boost yet to see if I make more boost or not, I bet the old scratched case was why my boost was still low, I was getting about 12-14 PSI on 15% OD but on a mustang motor with true dual exhaust. Stock heads and cam, stock everything.

This afternoon I plan on getting into boost to see how she feels, could the rotor pack bearings be bad? Could that cause the scratches? Cause the blower seemed fine and the rotors as well, I wonder if the damage was done before the rebuild. The rebuild consisted of all new bearings and seals, everything.

fturner
10-08-2007, 12:26 PM
I've heard that solid couplers can cause a lot of noise, especially at idle. Went I put my 94 blower back together I used the spring loaded coupler and all is quiet.

CMac89
10-08-2007, 12:54 PM
The scratches are completely normal in the case. Eaton builds them to obtain as little clearance possible and the scratches become a result of this. Some will be scratched more than others depending on the amount of coating, if any.

You don't have to seal the rotorpack to the case, only the snout to rotorpack. This is the way Eaton/Magnuson build the blowers.

fturner
10-08-2007, 02:06 PM
If you don't seal the rotor pack to the case, your inviting boost and vacuum leaks, which I've seen. One side needs to seal to keep the oil in, the other side needs to be sealed to keep the boost and vacuum in, or does that not matter anymore CMac?

Every blower I've taken apart has remenats of seleant on both sides?????

V6Sprout
10-08-2007, 02:38 PM
Yeah I figured some scratches were normal but mine had A LOT of bad ones, you can feel the grooves with your fingers. I have a stock coupler soI may throw it back in there over the winter, although it doesn't rattle AS BAD as the older blower. The rotors I put in the 95 case are 89-93 uncoated rotors.

Got into boost today and can still only hit 12 PSI on my gauge, but I think my gauge is 1-2 PSI off, considering where the needle sits when the car is off. So I might be getting 14PSI with 15% OD

CMac89
10-08-2007, 04:45 PM
If you don't seal the rotor pack to the case, your inviting boost and vacuum leaks, which I've seen. One side needs to seal to keep the oil in, the other side needs to be sealed to keep the boost and vacuum in, or does that not matter anymore CMac?

Every blower I've taken apart has remenats of seleant on both sides?????

It's not a twin screw blower there isn't internal compression. I didn't use any sealer for my blower. No signs of leakage and it runs well.

Do whatever you want I guess.

fturner
10-08-2007, 05:32 PM
It's not a twin screw blower there isn't internal compression. I didn't use any sealer for my blower. No signs of leakage and it runs well.

Do whatever you want I guess.

Even if its only a roots blower, no matter what there will always be compression even if thats not the intent. Your moving air and the very nature of moving air compresses it. Better take a look at physics 101 again.

I found a leak on mine that was costing me 2 psi and it was through the mating surface from the rotor pack to the rotor housing. Got it back when I resealed it. Since your the know it all, explain that.

CMac89
10-08-2007, 05:57 PM
Seems like you explained yourself. Maybe you should explain how it didn't make a difference between sealing and not sealing my blower. It only takes a thousandth of an inch extension of the case to decrease the efficiency of a blower.

Just because I relay my information to people doesn't make me a know it all. You keep saying that and you should because it's cool.

ANYWAYS, more important stuff. If Mr. Turner is certain the leak wasn't from the top, inlet, intercooler tube, etc.. then just be certain and go ahead and seal it. Just put on a thin layer so the silicone doesn't extrude into the case.

V6Sprout
10-08-2007, 06:33 PM
I sealed both side and the side of the rotor pack I did a very thin coat and after I tightened the bolts there was some RTV residue by the rotors, I kept spining the rotor pack by hadna dn kept taking out every bit of rtv, little by little till the rtv was completely dried, all is good.

CMac89
10-08-2007, 06:47 PM
I sealed both side and the side of the rotor pack I did a very thin coat and after I tightened the bolts there was some RTV residue by the rotors, I kept spining the rotor pack by hadna dn kept taking out every bit of rtv, little by little till the rtv was completely dried, all is good.

That's the real reason I quit using RTV there. Just got annoying.

Let us know how it goes.:)

CMac89
10-08-2007, 09:27 PM
I forgot to say, Happy Birthday to you and me!!!!

V6Sprout
10-08-2007, 09:59 PM
ahh cool, thanks.

Blower seems to work fine right now, like I said the rattle is not as bad, I will try the stock coupler over the winter and see if that helps the noise at all.

Jason Wild
10-08-2007, 10:35 PM
Like other have side no need for sealer on the case to rotor pack unless the two are no longer flat. I have take two blowers apart that had sealer there and they both rattled like mad remove the sealer and it was gone.because the rotors were not SQ. to the case. As for the spring loaded coupler there only good for so long till the spring get weak and lets it slip then you will think your blower is about to blow up.

pablon2
10-08-2007, 10:54 PM
FWIW, MP seals the rotor pack to case, but not the snout to rotor pack.