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				11-03-2012, 02:13 PM
			
			
			
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					Join Date: Dec 2001 Location: Louisville, 
						KY Cobra Make, Engine: I'm Cobra-less! 
						Posts: 9,417
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 Chas,
 It depends on the journal size.
 
 Most of the bearing manufacturers tell you to be at about .001"/inch of journal, and you add a half thou for the "hipo" stuff.
 
 My SBC rod journals are usually at around .0020-.0025".  BBC journals are the same.
 
 Cleveland, SVO, and FE main journals are around .0027-.003".
 
 My BBF and Windsor stuff is around .003" on the mains.  If it's a few tenths each direction, I don't sweat it.
 
 Cup engines run really tight clearances (they are pretty small journal though) and you know what kind of rpms they pull.
 
 There has always been a tendency to start opening up the clearances when "race" is written in front of "engine", but I've never really seen the need.
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