I'm just want to know how high of an rpm can the stock 87-91 TII rotor bearings can take? I put in a 85 PSI Oil pressure regulator. Just wondering if I should change them because i'm in the process of rebuilding a motor. Any help would be appreciated. Also this motor is intended to run more than 15 psi and hit 8k RPMs with a T66. Any info will be appreciated, was thinking of chaning to 93-95 rotor bearings, but they are bit more than the stock ones.

 

I dont think its the bearings that you have to worry about for higher RPM's. If you want to upgreade them go with a window type bearing for better oil circulation. You may want to look at hardened stationary gears if you want to steep the RPM's up.

 

Indirect answer: The RACING BEAT and the MAZDATRIX catalogs give lots of information on subjects like this. Note: Their online catalog is not the one I refer to. You pay around 10 bucks for one and have it sent to you. Again, not just the items online at racingbeat.com or mazdatrix.com

 

We use Amsoil synthetic oil and Mazda factory bearings and stationary gears on our drag car (It revs way over 10,000 rpm).

 

Hrm, I was talking about the Rotor bearings and not the stationary bearings, but that's OK. You all gave me good tips, is that when I took my friends engine apart the rotor bearings were scarred and the stationary gear bearings weren't. But I think i found the problem, the rotors were mismatch, wrong letters, on was a D rotor and the other one was a A, if that makes a difference.