Is anybody running different sized cams in their DS? For example a .425 intake and a .395 exhaust? what makes the cam people offer cams this way? What are the power characteristics based on?

 

??

 

I am running the "staggered" cams. The RWR A2, I don't remember the specs right now (brain fart) but it is something like your example. The reason I chose these cams were on a recommendation from both Elliot at RWR and my machinist that did my porting. There is a rule of thumb on engine building that you want to achieve a 25% differential between the exhaust and the intake flow. As an example, if your intake tract flows at 300 cfm then the most you want for exhaust is 225 cfm. Otherwise you will get too much scavenging of the fuel charge and actually lose power. My porting was done with these cams, so I don't know what effect the cams alone would have. But according to Elliot, "Ron like these cams the best", so I was told.

 

I'd like to know to what degree can you change your cams before you need headwork?

 

With what KenDS said would that also mean you would lose power running a straight pipe, as in no muffler? Just curious.

 

I just got a set of cams - exhaust is .396 lift, intake is .426
Not sure how the mix-up occured, but I'm willing to try them out, gotta go shim-under-bucket though for that lift.
They are supposed to be Pami cams - anybody know the grind specs to all the Pami cams?

 

Ward660R,
Yep. A straight pipe without any backpressure in almost all cases costs power. There are exceptions, as in all out racing applications such as top fuel, alcohol cars, and Nascar, but even then the pipes are tuned to the motor not off the shelf bolt-ons. They produce power only at the top end and sacrifice power anywhere else.

 

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