How long to seal rings?

[vesnyder]

I just rebuilt my motor and am getting terrible milage and seem to be burning oil. Some have suggested the rings have not sealed. I have put about 600 miles on the rebuilt motor. How long does it normally take for rings to seal and what could I do to confirm it is in fact the rings?

Thanks

[Steve@Rennsport]

Vance,

Seating rings is ALL about technique,..........it can take anywhere 3-5 hours on an engine dyno all the way to 10K in the car, if not properly done.

Leakdown testing tells the tale about when the process is complete. New engines leak around 20-30% and around 2-4% when the rings have finally seated. If you have one of those devices, you can track the progress.