An argument for tracking used seal location

[JustJeff]

I'm doing my first ever rebuild and because I don't have any local experience to turn to for advice I've found myself getting down right OCD about the condition of my parts. My thinking is that being my first time doing this I'm more apt to make mistakes. I'm overcompensating by being overly picky about the things I can control.

It's a S5 JDM 13B that I'm rebuilding. On teardown I kept track of the FC seals by rotor, but not by position on each rotor. I had to replace the front rotor and did that with an FD rotor. It came to me with all the seals intact. On that rotor I tracked them. Every corner seal went back where it came from. Each side seal went back where it came from.

I specced out each rotor before assembly and found that every one of the FD side seal to corner specs were within spec. .0025-.006. Not a single one of the FC side seal to corner seal were in spec. All the FC specs were at .007-.008.

One factor to keep in mind. I kept all the seals in ziploc bags. One of the FC bags got moisture in it and rusted the side seals and corner seals. So I was working with less options when it came time to measure specs.

[j9fd3s]

not really sure what the question is, but i do try to keep each seal in its original spot. i'm not sure how important it really is, but it IS a good practice. now that the k2rd stuff is unpacked i even have a Mazda seal case to do it with.

part II is that with side seals you want it as tight as you can get it without binding, which is closer to .002" a turbo can be .0025" the .010" mazda spec is WAY out there....

part III along with the seal case, and some pickiness about the seal clearances the next step is the engine build sheet. our piston engine rebuilder gave us a really nice sheet that described the original measurements, the machining step, and then the final measurement. i thought it was really nice.

[JustJeff]

^My post ins't so much a question. I'm just relaying what I found. I've heard and read different opinions ranging from never re-using side seals, to yes use them but put them all back in the same slot, to, it doesn't matter at all just spec them before you use them.

My first experience is far from conclusive, but the FD rotor that had every side seal and corner seal back where it came from is dead on in spec. The FC that did not have that treatment..they are all out of spec.

[j9fd3s]

there are two ideas here. the first is simple, its a good idea to keep a seal that is worn into its groove, in the same groove if it isn't replaced. just like its a good idea to put a bearing back onto the same journal etc etc.

the second thing, is that if you're not using new rotors the side seal grooves are probably different lengths. the rotors are actually kind of flexible, and they do get bent here and there. so if say you fit a side side to groove #1, to a clearance of 0.0002" if you move it to groove #6 on the other side it might have a clearance of 0.10".

also it seems like the side seals wear the quickest, AND their role in sealing, is pretty critical, so you want them to be on the tight side of mazda's spec. 0.006" might be in spec, but just barely, and that's no good.

[JustJeff]

I've got the new side seals clearanced and waiting for assembly. I've got them all at .002 clearance. And man did I feel OCD grinding those down. Trying to find the perfect balance between not binding or grabbing and not too much clearance drove me absolutely mad. I spent an unhealthy amount of time checking, checking, checking and checking again and again. Anyone watching from afar would have suggested counceling...and that's fine by me.

[j9fd3s]

I've got the new side seals clearanced and waiting for assembly. I've got them all at .002 clearance. And man did I feel OCD grinding those down. Trying to find the perfect balance between not binding or grabbing and not too much clearance drove me absolutely mad. I spent an unhealthy amount of time checking, checking, checking and checking again and again. Anyone watching from afar would have suggested counceling...and that's fine by me.

lol, yeah it does take FOREVER :rofl: