The question might seem a little vague. But if through a better intake manifold a given set of heads could flow another 20 to 30 cfm on the intake side, what might be done to the cam on the ex. side to complement this? More duration, more lift, or a little of both? Right now the cam has a 4 degree difference in dur. in the mid 22x area. Lift is in the .54x range on both sides. Would to much ex. dur. bleed off needed compression? Any ideas are welcome. And if someone would like to take a stab at some new cam specs. with these questions in mind I'm all ears. Please keep in mind though this is on a stock low mileage shortblock that peaks now at 5900 and would like to peak no higher than 6200 with a cam change. Current dyno #'s below. Thanks for reading, Rick

 

I don't think that an improvement of that nature really makes it neccesary to change the cam. However, you could probably put in another couple of degrees of exhaust duration. Or, to do it the quick and dirty way, use say... 1.6 rockers on the intake and 1.65 on the exhaust.


Keep in mind though that a lot of what I think I know may be outdated.

 

LRN, thanks for the reply. I'll keep it in mind.

 

Depends on your intake to exhaust flow ratio and whom you talk to. Comp cams recommends a single pattern duration cam if the flow ratio is 75%. Less that that, and you need a dual pattern with less intake duration.

Based upon their recommendation you could add intake duration to the cam to better utilize the extra flow.