Yesterday I drove to North Carolina to a friend's shop. He runs a Super Stock program and does all his own machining/assembly. He has a Super Flow 600 flow bench.
My goal was to flow my heads, both my intake manifolds (Performer RPM and Dart single plane) and to CC the heads. After a short tutorial on how to use the flow bench I was on my way. All measurements were taken at 28" and we did not use a pipe on the exhaust. The bore fixture was 4.125". I'm not sure what impact the smaller bore fixture had on the intake flow #'s, nor am I sure what not having a pipe on the exhaust hindered. Here is a link to the results:
http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/flownum.mht
I ran out of time and was unable to flow all the cylinders. I did both intake/exhaust on the passenger side head and a few runners on the driver's side head. I'll have to say I was somewhat dissapointed in the results. As you can see the flow fell off quite a bit at .600 lift; at least when compared to the advertised numbers that I got from Canfield's web page. The exhaust numbers were pretty close but the intake flow was off by a considerable amount. After careful examination of the heads I think I've come to the conclusion that they weren't ported to the extent that I originally thought they had been. It doesn't appear that any work has been done to the short turn radius. It appears as if the casting flash was removed in the intake runners and not too much else. That said, the numbers that Canfield advertises on their website are for box stock heads. I'm puzzled as to the difference. Maybe it was something with the manner in which we tested them?
I also tested both of my intake manifolds. We installed studs on either end of the head being tested so that we could easily attach/remove the intake manifold. When each intake valve was at full lift we would attach a manifold to test. It was really interesting to see the impact that the manifold had on the heads at full flow. Some of the intake runners on the manifold read different by just rotaing the manifold 180 degrees on the head. I'll have to say I was impressed with the way the little Edelbrock Dual Plane intake flowed. It flowed nearly as well as the Dart despite having a smaller runner. The #4 and #5 intake runners on the Dart were dragging down the max flow by ~25CFM. We ported the Dart intake in small increments taking it back to the flow bench at each stage to measure the changes. When all was said and done the Dart was flowing at FULL capacity on each and every port. I'll try and post some pics of the changes we made to the manifold. The biggest gain on the intake was made by raising the roof area in the plenum where the air coming in from the carburetor transitions into the runner.
I'll have to say that other than having to do a ton of driving (340miles each way, same day) that this was a very rewarding learning experience. I now understand why head flow is such a black art

My goal was to flow my heads, both my intake manifolds (Performer RPM and Dart single plane) and to CC the heads. After a short tutorial on how to use the flow bench I was on my way. All measurements were taken at 28" and we did not use a pipe on the exhaust. The bore fixture was 4.125". I'm not sure what impact the smaller bore fixture had on the intake flow #'s, nor am I sure what not having a pipe on the exhaust hindered. Here is a link to the results:
http://bellsouthpwp.net/k/_/k_jett/Images/Canfield/flownum.mht
I ran out of time and was unable to flow all the cylinders. I did both intake/exhaust on the passenger side head and a few runners on the driver's side head. I'll have to say I was somewhat dissapointed in the results. As you can see the flow fell off quite a bit at .600 lift; at least when compared to the advertised numbers that I got from Canfield's web page. The exhaust numbers were pretty close but the intake flow was off by a considerable amount. After careful examination of the heads I think I've come to the conclusion that they weren't ported to the extent that I originally thought they had been. It doesn't appear that any work has been done to the short turn radius. It appears as if the casting flash was removed in the intake runners and not too much else. That said, the numbers that Canfield advertises on their website are for box stock heads. I'm puzzled as to the difference. Maybe it was something with the manner in which we tested them?
I also tested both of my intake manifolds. We installed studs on either end of the head being tested so that we could easily attach/remove the intake manifold. When each intake valve was at full lift we would attach a manifold to test. It was really interesting to see the impact that the manifold had on the heads at full flow. Some of the intake runners on the manifold read different by just rotaing the manifold 180 degrees on the head. I'll have to say I was impressed with the way the little Edelbrock Dual Plane intake flowed. It flowed nearly as well as the Dart despite having a smaller runner. The #4 and #5 intake runners on the Dart were dragging down the max flow by ~25CFM. We ported the Dart intake in small increments taking it back to the flow bench at each stage to measure the changes. When all was said and done the Dart was flowing at FULL capacity on each and every port. I'll try and post some pics of the changes we made to the manifold. The biggest gain on the intake was made by raising the roof area in the plenum where the air coming in from the carburetor transitions into the runner.
I'll have to say that other than having to do a ton of driving (340miles each way, same day) that this was a very rewarding learning experience. I now understand why head flow is such a black art