Hi i am in the process of rebuilding my Turbo 2 engine and have just got the rotors milled out to 3mm and are buying all new 3mm apex seal parts. Should i replace with new rotor bearings? My mechanic said mine are in OK condition and are reusable. What are your views ?

 

If the bearings look OK and your mechanic says they are OK then don't chamge them. I have read in a couple of places that the rotor bearings do not take anything like the 'hammering' they do in a boinger and should be good pretty much forever . They are also much larger in area c/w mains or rod bearings, so if the oil and filter has been changed at the correct intervals and the engine has not been over-revved to the extent of flexing the eccentric shaft they should be in excellent shape.
I have seen bearings from a 12A that had done more than 220,000 miles and the bearings looked almost as good as new.

 

U should get it replace! i learn the hard way.. im in the process of getting my motor rebuilt for the 2nd time.. the first time i juss told them to replace only the things that need to be replace, juss to save the ex-money. It was a bad idea. Now im going to end up spend close to $4500. But lts going to be like a new motor!

p.s. im getting it done by jeff at rotary power

 

Same question, different circumstance. Rear rotor bearing looks perfect. No scratches, no copper showing, just nice gray babbet all the way around, both gear side, and open side. Front rotor, different story: open side shows a nice bearing (same as rear), gear side as three areas of copper showing, each directly under the rotor face...

Also, the motor had a light, but distinctive, knock when idling after long and/or hot runs - even with 20w-50 in the crankcase.

I'm guessing that bearing will need to be replaced, and then the oil clearances rechecked.

Advice?

Just checked mazdatrix for the bearing tool... $87

 

FWIW RB says to not replace rotor bearings unless absolutely neccesary. Seems they've had more failures of new bearings than bearings they've reused.

Steve, have a machine shop press a new bearing in. If you have the mics you can check the clearences. Otherwise just take you e-shaft in and have them do it.

Chris