Thread: I rebuilt my M90 rotors at home

Heres A picture of my rebuilt M90 rotors ,they have been coated in a special dry film thats designed for Rotors



This link is for some youtube footage I took

YouTube - vsl67's Channel

This link is for the Australian L67 forum where I did my rotor rebuild in detail ,I hope it might help someone here ,feel free to ask questions

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Joined: Thu Dec 11, 2008 9:33 am
Posts: 172 As for rotor timing I thought of this the rotors will only fit the case together one way ,so my idea is to use the case a as jig ,put the rotors in the case ,bolt the rotor plate on and press in the bearings on the rotor ends and then the gears the case should keep everything square

Ok I have got the rotor block back from the engineers after he tidied up the egdes where the bearings came out only removing about a 1mm hardly worth doing I know but this elimnates any chances of chips coming of later

Also the rotors have been put into HPC for a Df3 coating as the Epoxy paint was starting to chip and flake pretty badly ,I looking at a teflon coating but because the rotors are steel it took an undercoat to apply it making it too thick ,so after a quick call to Melbourne they found out this is most common coating for these rotors they use

Now the plan for the bearings at this stage is to press them in using Locktite 609 compound (operating temp 150 degrees )and let it cure for at least 24 hours ,its especially designed for this sort of application this is just a safefty measure because on further investigation there is no way these bearings can move becuase they are held in place by the rotors

so I will let you know in about a weeks time how I go with assembling them ,I either have a good set of rotors or a really nice paper weight

In the mean time keep the potential problems I might encounter coming in case I have missed something

Heres a picture of M90 rotors next to 6/71 rotors

The rotors Are now in the car and I have taken it for A 100km run ,Firts thing I noticed was how quiet it was (no rattles), I pushed the car to 5500 rpm until it hit the rev limiter and gave it a thrashing from rolling starts to stops starts aswell as general traffic with no dramas ,overall the car is smoother and more responsive as for boost I run uncooled so I only have a 10psi pulley but I would see 12-13 psi at W.O.T with the old rotors ,this hasnt changed other than the boost comes on a bit smoother






As for aligning the rotors I put them in the supercharger case and lined everthing up by eye very carefully that is the center line of the rotor to the "V" of the next rotor ,I tried feeler gauges and tin foil to adjust the gap but none of them worked
Then I put the bearings in t making sure it was seated in the block with plenty of locktite 609 and then very carefully not to move the rotors and then drove the bearings on with a socket hitting the center only ,until everthing was sitting flush with the case and again checked the bearing were still seated in the block

Finally I put the gears on the top of the rotor shafts already meshed and droved them on together so they are going on meshed tap the the other on with a socket until seated

Im not sure If I got lucky or this will every time ,Im going to do some more experimenting ,but I am convinced most of the gaps are self adjusting and are regulated by the bearings,gears and block

I havent noticed a boost increase yet but if its there it will be higher up in the RPM range but I havent lost any boost either
The bearings are $12-$14 for the pair ,$30 to clean up the bearing seat edges (you dont have to do this if you dont want to) , $80 each for the rotors to be coated in DF3 including stripping and $12 for locktite 609

your looking at $200 - $214 in total

some things to watch for if you attempt this

1 when you remove the bearings hit the inner cone only using a socket just big enough and an extension and be careful you dont ram the socket through the seal and stretch it

2 leave the locktite 24 hours before you use it in the car and use plenty of it taking care to completely clean the mating surfaces

3 Dont use a press more can go wrong using one if you stick to sockets you have more control over how things go together and will be able to feel and see if something isnt right

4 Dont forget to remove the bearings seals

5 Dont attemp this unless you have a spare blower case off the car you can stand on its end it makes assembly and timing so much easier

6 Even though I didnt do this try and scribe 2 marks on each rotor shaft & gears for aligment just in case you need it

7 If you get stuck and the supercharger rebuilders want a fortune to help find a Jet Ski mechanic these things use rotors too

The funny thing was I read heaps of stuff on the American forums about people trying to reco the rotors only for them to fail due to the wrong timing I dont know what methods or what mechanical skills they had ,But it took me under 10 ten minutes and only one attempt luck maybe ?

On the subject of rotor balance that was raised earlier in the thread ,I relised the coating would not have any affect on it compared to a stuffed bearing imagine the forces it would have on it at high revs with a bearing is slopping around

No sorry I didnt need to replace them and if your careful when removing the bearings they are usualy good ,

Originally Posted by bluegtp91

X2 on the link...but NICE mate!! LOL Sorry I had to

Hey you speak fluent Australian ,thats awsome dude lol

them rotoers look good. I might have to get that done.