Please note that the PICTURE UPLOAD function is not working. The iBoats Forum Moderators are working with the system administration folks at the parent company to get the issue resolved. This happened about a year ago and here we are again. In the meantime you can post photos as links to a picture hosting site of your choice. We are sorry about the inconvenience and will advise when the issue is resolved. Thank you for your patience.
I ran the last motor on the stand for an hour, changed the oil, installed it, put 15 hours on it, then changed oil again. Now will change every 50-100 hours
Standard practice is 10-25 hours with break in oil for a naturally aspirated standard build sbc. Different motors and build specs could mean shorter times. If in doubt, change it earlier/more often