So this needs to be mentioned:
I get rotors every week from people that are either
- standard OEM
- Not machined properly
If running a rotary engine in serious street car or racing the rotor sides MUST I mean MUST be clearance PROPERLY!
These are two sets I did yesterday, one out of a circuit race car that had done 3 events (brand new stock part).
I get asked all the time, 'but Mazda do a shoulder to stop the tilting on all new rotors" YES I say ............. the C-u-n-t-s do not work! *see proof*
Also the standard of new Mazda parts is a fucking joke, nothing is geometrically correct and parallelism to opposing rotor lands is bad on most and varies rotor to rotor.
I have seen some 'kid run' operations surface grind these LOL. This is NOT how to do this process correctly ALSO just doing the rotor tips or under cutting these IS NOT the correct way either.
I worked this all out when I was 21 years old (long time ago now) and working as a qualified Fitter and Turner putting myself through Mechanical Engineering school after hours, a few decades on I still see the same mistakes being made ............... thus the post here!
Stock molestation:
587bhp (engine dyno) 13B road race car (brand new Mazda Rotors)
Correct Clearance Completed: