I pulled the rear stationary gear on my S4/5 Hybrid Turbo motor since I had the clutch off and the engine is out to inspect the bearing to see how worn it is. The bearing has 1/3 of it showing copper, and looks quite worn.

I just happened to be going through a bunch of parts, and I found a set of front and rear stationary gears with bearings showing no copper, the gears also look less worn. If memory serves me correctly, these are from a S4 NA engine.

My question is, could I just put these stationary gears and bearings in my motor? Since I will not be disassembling the motor, I will not be able to measure the eccentric shaft, looking online, there is no different bearing sizes for the FC gears/engine, so in theory, I should be able to, but I figure I should ask the experts first.

Power goals with this motor is 400HP eventually, and it will be a street driven engine, with the occasional drag race, no road racing.

 

1/3rd showing copper is normal. That's the manufacturing high spot worn round again, and the reason why new-bearing engines have a break in period 2-3 times as long as with used bearings.

If it isn't scored, and oil pressure was good, I wouldn't be concerned one bit. The overlay is so thin that if it exists at all, your clearances are still good. (A low buck way of making race-clearance bearings is to scrape/sand the overlay away so it is copper all the way around)

I have replaced stat gears in-chassis, it's no big deal other than pulling everything apart. But that was because I had 20psi oil pressure max, and the bearings were .007 oversized and heavily scored.