Suggestions on when to do a rebuild

[Sephitrask]

Well, I was going to post this in the 8 forum, but I figure the information is prolly universal. And I did attempt a search on this, but didn't come up with anything constructive.

So the question is this: I have a 05 rx-8 with 90k on it, original motor. I have premixed since about 70k, and have used only 20w 50 since I got the car. Currently there does not seem to be any issue with the motor; It idles fine, and performed like a champ at DGRR. From what I have heard, when it comes time for a rebuild, at least one item (rotor, housing, etc) needs to be replaced, depending on the failure mode. So what I am wondering is, would it be beneficial to tear down the motor and rebuild it BEFORE it failed? I would assume it could potentially save a bit of cash doing it this way. If anyone else does this, about what mileage would be suggested?

Thoughts?

[N.RotaryTech]

I would not rebuild it until something gives way, coolant / oil seal or compression seal etc.
Unless I wanted to upgrade the internals. Porting, etc.

Just take care of it and it should go a long way.

[NoDOHC]

If you are running non-turbo, they will typically give some indication of age before they let go. With a Turbo, you could destroy a new engine as easily as an old one, so there is really no major advantage to a rebuild there either.

If compression is good, you are probably Ok to keep running it. It will probably start flooding and idling a little rough long before you have any actual failures.

[TitaniumTT]

These men speak the truth. N/A's can and do go a loooooooooooooooooooooooooooong time. If it ain't broke, don't fix it.

The problem is, with the mileage you're at, and the fact that you've only been pre-mixing for 20k, those housings probably aren't reuseable anyway, at least not highly useable if that makes any sense.....

[project86]

ya my fc had 140k on it when i tore it down. after looking over alot of the parts im surprised at how well it ran... corner seals were f***** i had gouges in rotors and gouges on the leading edges of ports. i was getting some smoke but i think it was primarily from premix.