I switched a while back from a regular vic junior to an edelbrock CNC port matched vic junior and lost 2 MPH in the 1/4 that I cant seem to get back even with tuning. The regular vic junior ports were smaller than the intake runners on the 195 AFR heads. Was wondering if the antireversion properties of a smaller manifold port/larger intake runner was actually helping make power in my situation. Has anyone else had a similar experience? I still have the old manifold and may switch back if I cant find this lost power.Thanks,
Doc

Originally posted by Racerdoc:
I switched a while back from a regular vic junior to an edelbrock CNC port matched vic junior and lost 2 MPH in the 1/4 that I cant seem to get back even with tuning. The regular vic junior ports were smaller than the intake runners on the 195 AFR heads. Was wondering if the antireversion properties of a smaller manifold port/larger intake runner was actually helping make power in my situation. Has anyone else had a similar experience? I still have the old manifold and may switch back if I cant find this lost power.Thanks,
Doc Racerdoc,

Since no one else responded I'll take a stab at it. I would say most certainly that the port work you did accounts for the difference in performance. I think that the smaller intake ports may help to deflect gases that spill over during the exhaust stroke (thereby poluting the incoming charge). When there is a difference in floor height (lower on head than intake) you almost certainly better to raise the floor of the head rather than lowering the floor of the intake. Take this info with a grain of salt as I have ZERO experience with flow benches/head porting :D

I'm gonna go ahead and port match my intake,it has to come off for a new gasket anyway. Plus I've been curious about results in the past. Heres a quote from cc about port matching : "What happens when air flows from a smaller opening into a larger one? It's velocity slows down, and the stagnent air behaves unpredictably. Not good". If memory serves, the advantages of higher floor heights on the intake side is that it helps to create a more even air/fuel mix.

Did you make sure the ports and runners were lined up properly? When the intake is matched to the head, alignment becomes critical. Any mismatch causes one side (or top/bottom) of the manifold runner to overhang the port (not really bad) and on the other side the port to overhang the runner (very bad). When I did my regular Victor Jr., I undersized the runners about .010". This made installing it much easier since a slight mismatch didn't let the port overhang the runners.