MustangWorks.com : Ford Forums - View Single Post - need help- oil in breather & air/fuel problems

Jeff Chambers · 09-19-2006, 07:00 AM

Normally aspirated I'd be shooting for 12.8 to 13.0:1 at WOT. A/F at idle will be dictated by other factors such as curb idle setting, corner idle adjustment, vacuum level, power valve setting, etc. Try to get your idle to 14.7:1 or higher. Don't worry about it being too lean at idle; the engine isn't under any load at idle so there's no fear of damaging the engine. Its not uncommon to see a car idling at 17:1 or more. The only effect of doing so is increased NOx emissions and somewhat higher engine temps.

09-19-2006, 07:00 AM	#3
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Re: need help- oil in breather & air/fuel problems Normally aspirated I'd be shooting for 12.8 to 13.0:1 at WOT. A/F at idle will be dictated by other factors such as curb idle setting, corner idle adjustment, vacuum level, power valve setting, etc. Try to get your idle to 14.7:1 or higher. Don't worry about it being too lean at idle; the engine isn't under any load at idle so there's no fear of damaging the engine. Its not uncommon to see a car idling at 17:1 or more. The only effect of doing so is increased NOx emissions and somewhat higher engine temps. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"