SBM Edelbrock/Speedmaster Head Data
I’m not sure what you are trying to do here. Why not fully port the head to the 285-290 cfm capable with a 2.02 valve then start your mods.
I'm trying to learn. I could be totally wrong in my approach, but my thinking is this:
Looking at small block mopar heads the Edelbrock style head is an improvement over the factory heads. The TF head is an improvement over the Edelbrock. Part of that improvement is a better combustion chamber with different top cut angles and pressure recovery designs.
Why does one head flow better than another? How can efficiency be improved? How can I achieve the proper port size, velocity and cfm for the particular engine?
For instance: I bought one Speedmaster head and one Edelbrock head. I tested them both in stock form. The Speedmaster had higher cfm numbers, but it also had a larger port volume and a larger push rod pinch area. It also seemed to me that the Edelbrock had better seat angles below the valve, but the Speedmaster had better angles on the top cut. The top cut on the Edelbrock is 0 degrees. So, the air sees a 45 degree seat, then a 45 degree angle change. That can't be good. So, I'm trying to get a feel for how 'bad' it is and if it can be improved.
So why am I posting this stuff? Again, education. I'm sure there are a few other nerds out there like myself who will be fascinated with numbers. I'm also willing to take (some) abuse that comes with posting to get my thoughts and ideas challenged and corrected. Painful learning seems to have worked for me in the past.
Oh, and I am hoping to get to the 290-300 cfm range. I just want to understand how and why I got there.