Dave, Glen and the group, The important thing is to not overheat the engine, while maintaing a load on the engine as much as possible.
Ground running should be limited as cyl temperatures can get too high very quickly with new parts and low power....REASONS...No or little air flowing over the cyls, thus overheat; At low manifold pressure and new rings/cyl, there is considerable leakage of combustion gasses (blow by) into the crankcase...... Running a new engine at high manifold pressure --high loads causes the rings to be pushed against the cyl walls ( the rings have a taper on the back side of the rings to make the cyl pressure push the rings against the cyl walls. This causes the rings and cyl walls to match wear; and prevents the deposition of carbon in the piston grooves. So this additional pressure on the back side of the rings pushes the rings against the cyl walls, making them "wear in".and "seat". Once the rings are seated, then you want the best oils possible to prevent any additional excess wear....thus use the best available.... In water cooled engines --autos --where the engine demensions are more constant than an air cooled engine - the rings will seat in just a few full throttle accelerations. Takes a little longer in an air cooled engine and also depends on how well the cyls are machined. New rings in old cyls take more "Running In", than do new rings/new cyls...as the new deminsions are more constant. Do not run the engine on the ground for long periods unless a special prop is used along with a fan to keep the engine at proper temperatures...as found in an engine manufacturers/rebuilders test cell. Hope this all makes sense. Regards, Harry Francis Blacksburg, VA. __________________________________________________________________________ ______ To unsubscribe from this list please send mailto:[EMAIL PROTECTED] _____________________________________________________________ Want to find the best email lists? Check out the Topica 20! http://www.topica.com/topica20
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