Main bearing Oil Clearance?

George Roffe geo3@earthlink.net
Mon, 18 Nov 2002 11:44:41 -0600


JFormantes@aol.com wrote:

><< Nissan doesn't recommend it. >>

>Why?

No idea.

>I was thinking it will be better sealing ( and the rings has less stress?)
>than 0.0004 inches but I am worried about the oil can a regular 5W-30 oil
>will pass through this 0.0001 in.clearance? If it does no good,  I'll stick
>with what's on the FSM.

First of all, your oil sealing is handled by your rings.  The gap between
the piston and cylinder wall is for lubrication I would imagine.

Unless you've done a ton of research, and can positively identify why you
want to deviate from the FSM and positively know why it will work (or at
least be willing to risk and entire engine on your theory), I would stick
with the FSM.  You have to ask yourself why you are trying to out engineer
the factory engineers and if there is any advantage to it (I doubt it here).

George Roffe
Houston, TX
http://www.nissport.com