Quote Originally Posted by S V R E
Thanks Pat. I build for a lot of guys that race the NMRO circut ranging from 505ci to 660ci. Some of the classes I must maintain a conventional style head becouse of the rules and I use Pro Topline 360's ported in house. We have them from 440cfm-460cfm and usually make between 900-1000 depending on the aplication. All so far have been single carb cast manifold. I agree on narrowing the lobe sep. With the engine and the duration being that small, it will like it tighter.
There is no way a Pro Topline 360 cc head will flow 440 -460cfm you would be lucky to break 420 cfm.The Brodix BB-4 Xtra with a port volume of 390 cc and fully CNC'D with 2.350/1.90 valves on a 4.60 hole will flow around 445 @ 28" of H20 at .800 lift.