Filing out rotor slots?
 

So I made a post a while ago about a poorly installed bearing on one of my S4 rotors, damaging the rotor slightly. Never got any real responses but by some sheer dumb luck I found a set of S5 rotors at a swap meet for pennies. The only issue is the motor had blown a side seal. Visually you can barely tell, but if you look real real close you can see a slight line on one of the faces where the side seal navigated to the combustion chamber and pinched. All the seals are out, and the rotor looks excellent, but the corner that ate the seal is ever so slightly tight for the apex, corner, and side seal slots where it grabbed. When I say ever so slightly I mean you can slide the seals in and out with slight effort, but not enough that the springs will move them on their own. What can I do about the corner and side seals here? Seems to me the cast could be difficult to work with...

A picture would be of help, but so long as the integrity of the supporting grove faces aren't compromised I don't see why you wouldn't be able to file the affected areas to get the proper clearance.

Picture wouldnt show much besides a very slight line on one of the faces where the side seal got jammed, and based on the position, presumably promptly tossed out the exhaust port. I just dont know what methods would exist for filing a slot as small as the side seal slot, and what to do about the ever so slightly tight corner seal slot...

Could try taking a strip of sandpaper (somewhere between 180 and 240 grit) and fitting it into the side seal grove. You might have to stack two strips together for added thickness to get some outward pressure on the side you want to clearance.

For the corner seal, if its groove is pinched you can lightly tap the outer/apex edges out. Probably best to do with a brass punch and small ballpeen hammer but I've gotten away with using a socket extension.

Have you tried to put the old seals in and see what's free? about your old rotors, I have one with a bearing tab sorta like that and I was told not to worry about it and it's been just fine for a while.

if there was an oiling problem and the bearing wanted to spin, it would yank that tab right off, its kind of decoration

So I take it my best bet is just running the S4 rotors (I’m gonna press a new bearing in because screw it, I got one) and keeping the S5s on the shelf then? Ultimate end goal is N/A ITBs setup making 200 range.

btw same guy ended up selling me a pair of rotors from a CORVETTE, dude was on the engineering team for the rotary corvette and took them home when GM pulled the plug, I’ll have to post pictures soon here. They’re HUGE compared to the Mazda ones, and run dual side seals, and some absolute monstrosities of apex seals. One rotor is basically “ready to go” with a bearing and gear installed, the other was a rough mock-up casting before they did the gear bearing and oil passages. Bastard is heavy.

Now this is really fascinating. Please make sure to take lots of photos.