7MGE Engine rebuild

[oregonjoe]

I've been researching what type of oil to use for engine break in. Found this web site with some great explanation of what is going on and how to do it correctly

http://www.ntnoa.org/enginebreakin.htm

The bottom line is 30W NON DETERGENT

“The primary deterrent of break in is this heat. Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings.”

"If the wrong type of oil is used initially, or the break-in is too easy, rings and cylinders could (read will) glaze and never seal properly. A fresh cylinder wall needs some medium to high engine loading to get the piston rings to seat properly for good compression but make sure you don't lug or overheat the engine. Use high quality, low viscosity oil (Valvoline 30 weight), no synthetics, too slippery. If synthetics are used during initial break in the rings are sure to glaze over.”