322
how do these ported 302 compare to unported edelbrocks obviously ones a close and ones a open chamber but I was curious about the flowing aspect
Being that these are 2 totally different heads, with very different port sizes and shapes that there really isn't a comparision. Also the Eddy's will have much too large of intake runner for the 318 and kill low rpm performance and Tq. and worse than useing a 360 head on a 318.
The problem comes from the 318's bore size and not being able to use the amount of port volume that the 360 and or the Eddy's have. In short the bore of a 318 is just too small to pull effectively. This is why the engineers made 2 different heads for the LA engines. As they saw that one head wouldn't fit all.
As for the comparision that you want, first you would have to know how many cc's are in each head and then flow both heads. Useing the size valve that comes in them. Now if the 318/302 head which should be 118/120 cc's and the Eddy's are about 168/170 cc's then the flow will have to show a 29.5 % better flow numbers. So if a Eddy head flows 250 cfm's then the 302 head should flow 176.5 cfm's which is what they flow from the factory. In my dealings with the Eddy's they only flow 244 out of the box from Edlebrock. Now in a fully ported Eddy they flow in the 295 range with a 173 cc runner and a 2.02 valve, so now for comparision the 302 head.
The 302 head with gasket matching and bowl blending should be about 126 cc's with a 1.78 intake valve, this is a 17.2% reduction in port volume and a 12% reduction in intake valve size. So now if a Eddy flows 295 with a larger port of 173 cc's take the 295 cfm's X 17.2% and you would come up with 244 cfm's. But wait we still haven't figured the intake valve size difference in yet. Which is another 12% less area for valve sizes, so now the 302 head should flow 214.72 cfm's to be equal in port velocity and flow. But now this becomes interesting as the 302 head done correctly should flow in the 216-220 range and not being fully ported. With the head being fully ported it should flow in the 220-230 range.
This would show that the 302 heads on the 318 block bore size would be a much better head for performance and power, with better throttle response and Tq. due to higher port velocity and a ramchargeing effect.
Hope this expalins it better for you.