I have a running engine S4 NA that im rebuilding cause it has about 120k on it as a class project. When it was in the car there was some smoke coming out of the exhaust for about 15 sec until it warmed up. It was white smoke which i think is water. So what do u think would be the necessary seals for me to replace so this engine can run another 50k. I just want a daily driver so its not going to be abused.

 

It's more likely that the white smoke you saw on startup was oil. The oil control rings let oil past them (very slowly) while the car sits, and this is burned off when you startup the car. The older the motor is, the more oil will get by. A little smoke on startup is common.

If you open up the motor, you will have to replace ALL of the seals. A full rebuild kit will cost you around $1000, so don't expect it to be a cheap project. Honestly, if the motor has 120k on it, and it's just oil seepage, you can get another 50k out of it as is. My NA motor had 180k on it, and it could have gone longer.

 

You don't necessarily need to replace ALL of the seals. Most of the time the corner seals, side seals and oil control rings are still within spec and can be reused without consequence. I would still replace the apex seals regardless if they are in spec or not.

 

Ok so can i just replace the oil control rings and the apex seals and run the motor again?

 

Go here: http://www.atkinsrotary.com/index.php?pag=5

Replacing anything less than all of the seals/gaskets is the hack way to do it. If you intend to have this motor be reliable enough for you to daily drive the car, do it right. Anything else will have you guessing when it will lose compression.