View single post by Mark Rosenbaum
 Posted: 10-28-2005 03:32 pm
PM Quote Reply Full Topic
Mark Rosenbaum

Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
With good valves and properly seated rings you should see 125-130 psi in each cylinder (at sea level -- 10% less at an altitude of 4000 feet or so).  If your engine has been run for 15 hours -- the equivalent perhaps of 500 to 1000 miles of driving -- and you still have only 100 psi compression, quite possibly the rings are not wearing in properly.  If so, that would be the most likely cause of your excessive blowby.

Are you using synthetic oil at present?  The stuff is not supposed to be used during a break-in period as it is such a good lubricant that rings etc. will not wear in properly.