Engine Rebuilding... a couple questions

[Shane@DBPerformance]

The problem with doing hard breakin pulls on a turbo car is that it had better have a good tune in it to begin with or else you might damage the motor right away. Most cars don't have any boost, so even giving it enough load to get close to 0psi should be enough cylinder pressure. You want to do some long coast downs from mid RPM while in gear, that will pull a lot of vacuum and seat your rings in. If your rings aren't seated and you don't have full compression within 10-20 miles, then they probably won't ever get better.

[niterydr]

Originally Posted by ecoli

The problem with doing hard breakin pulls on a turbo car is that it had better have a good tune in it to begin with or else you might damage the motor right away. Most cars don't have any boost, so even giving it enough load to get close to 0psi should be enough cylinder pressure. You want to do some long coast downs from mid RPM while in gear, that will pull a lot of vacuum and seat your rings in. If your rings aren't seated and you don't have full compression within 10-20 miles, then they probably won't ever get better.

Exactly.
Do not hit boost, hince the term "vac" pulls. I usually rev a motor out to 2/3 its rev range and let it coast down to 2000rpm or so (usually end up doing 5000-2000rpm pulls).