Main bearing draining characteristics

Chuck Sea/Tac

Chuck Sea/Tac

Well-known member
Have an engine I just assembled and ran on a stand for an accumulative 30 minutes. Wanted to recheck lifters, and when I pulled the valve cover off , the center dam was full and poured oil onto the floor. Front and rear main feeders drain , but center does not. I pulled the crank back out, bearing was full of oil, and the feed tube clear. The parting line seems ok to me.
How does oil drain from mains ,and which is normal, drain or no drain.

Thanks
 
The oil seeps past the bearing surface. This tighter the bearing clearance, the slower the drain. Please forgive me for asking but you did clean out the tubes before you assembled the engine.
 
If the engine stops and the oil groove on the cam lines up with the oil hole it will drain fast

One of the "fixes" tried to stop rear main leaks is to drill through the Babbitt and cap to the oil return passage -- this will drain the chamber
 
Kurt in NJ said:
If the engine stops and the oil groove on the cam lines up with the oil hole it will drain fast

One of the "fixes" tried to stop rear main leaks is to drill through the Babbitt and cap to the oil return passage -- this will drain the chamber
Click to expand...
Kurt,
"Probably" best to leave "well enough" alone. "Some" leaking is jist typical of a Model A. (Keeps the underside frum RUSTIN'--LOL)
Bill W.:D
 
You must log in or register to reply here.
Back
Top