Main bearing Oil Clearance?

[JFormantes@aol.com]

Hi...I was checking out the haynes manual yesterday comparing all the specs
together (main bearing oil clearance) I noticed that the older engines like
E15/16 and Ga16DE has a larger clearances compared to SR20DE......why is that?

Also can I run 0.0001 or 0.0002 inches of  piston to bore clearance on SR20s?
instead of standard  min. 0.0004 inches. Any comments, explanations
adavantages or disadvantages are greatly appreciated.

Thanks.