Being a good ole southern boy I will keep this simple. Feel free to add ask questions at anytime. I will have to do this as time permits, but for some us, author included, I'm not boating so I have time. This is not the "ONLY WAY" or the RIGHT WAY. I just want to give you some basics on what to look at and how to go about making an educated guess on what stick needs to go in your engine
Here goes.
Most of us start out with basic combo in mind. For sake of this thread and an application we are all familar with we are going to use a 502 CID engine as our "Engine to Cam".
We need first to select a Max RPM that way we can get our first basic calculation down. REQUIRED CFM FOR ENGINE. For most part we run about 5500 max so we will use it. The formula as follows:
(CID/2) * 6500 rpm/1728 per cubic foot = need air flow
(502/2)*5500/1728= 798.90
Now we break that down to individual cylinders
Total CFM/ No. of Cyl= CFM Requirement per cylinder.
798.9/8cyl= 99.86 CFM
Now we know how much CFM we need to feed our 502 at our max rpm. Next we will calculate the needed cylinder head flow and cam duration to achieve this.
Any questions?