RB26powered74zcar Posted June 25, 2002 Share Posted June 25, 2002 If I were to retard my cam timming, which way would it change the gauge vacum, more vacum or less vacum ?? Thanks all joel Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted June 25, 2002 Share Posted June 25, 2002 I never used a vaccum gauge to time an engine but I would say retarding the timing would lower the vaccum as would an improper underich or overrich fuel mixture. Your fuel mixture should be correct before attempting any timing changes by means of a vaccum gauge. I maybe wrong on this.. but not this: You should be any where between a "steady needle reading" of 15 and 18 inches of vaccum on a stock engine at idle. Quote Link to comment Share on other sites More sharing options...
Guest Tom Scala Posted June 25, 2002 Share Posted June 25, 2002 I retarded my cam 4 crank degrees and saw little or no loss of manifold vacuum at idle. It's still around 19" at 1000rpm, but upper rpm (above 5500) power is up noticeably. Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted June 27, 2002 Author Share Posted June 27, 2002 Thanks guys, I thought it would show up in the vacum if I adv. it or retarded it. Right know I'm showing around 12 in. but maybe it's cause of the cam itself.... 490/480 Thanks again joel Quote Link to comment Share on other sites More sharing options...
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