The RPM Airgap for Ford Clevelands flow 290 on the worst runner and 340 or more on the best, stock. With a little radius work that goes up to 330 and 410 CFM.
In the article Steve used the E-tool and calipers. He states "After re-working the area, the port window at the pushrod bulge measured 0.930 inch by 2.225 inches. Increasing the available cross-sectional area to 2.07 SQ inches. That's a gain of over 17 percent. Intake flow responded with large gains showing the restriction here was significantly impacting the head's flow capabilities. (these are stock magnums and this was the 3rd step after bowl blend and short side contour). He took the pinch at the top from .800" to .930" using the E-tool.
Hi Charlie, You know im not a Mopar guy, but i think in general "extra airflow" can hurt higher revs more than lower revs, and conversely is needed to achieve higher ve at lower revs that the longer available time allows. Of course, we cannot measure the airflow of a running engine with a flow bench. - juhana
@@servediocylinderheads Let say the bare head flow high speeds (in a flowbench) and the manifold drops it down. That doesnt necessarily mean it is a waste when the speeds are targeted and like so things happen at a right time. -juhana
@@servediocylinderheads I mean its crazy what a engine may want. Some manifolds even have bends which you know makes it less flow efficient, but we should keep in mind that were dealing with pulsed flow and without the reflected intake pulse there is nothing to ram it with. -juhana
If i remember correctly the performer rpm is only like a 15-20 hp difference from a mid 80s stock midrise truck 360 4 barrel manifold. And thats stock for stock. Learning that. I decided i woulod put alot of work into the truck manifold i had. Took like 8 hours. But i managed to equal put all of yhe intake port cross sections to sligtly larger than the cross section on the ported 360 head. (Deep port matched) port matched all the wsy through those runners. Cut down the divider a bit and did the plenum work. Not sure how wrll it worjed yet. Transmission is a little low on fluid so it slips a bit.
(to tune of Devos working in a coal mine) Grinding anna port Grinding down down , working onna port going down down . Working onna ports ,woops about to slip now .
Sheesh, it looks like on the exhaust side he picked up the most by having Dr. E do a 6 angle valve job and then he profiled the guide boss. LOL. Doh!!! Bummer those dudes have to pass along. Appears he got 168@300 and 185@5, with a pipe the #'s are 175@3 and 208@5. You are right there already on the 500 #'s. (being an EQ not sure if it should be better)
looks like the air/fuel mix, like the dykem, is slamming into the straight up and down wall of the long (missing) radius. what good is an atomized a/f mix after it slams into the wall and breaks up? the long radius is just that. a radius, not a straight wall. an hour glass shape is much more efficient.
@@servediocylinderheads i understand you're just doing a "clean up" but there is enough material in that straight wall to put in a long radius. the dykem doesn't lie. the air/fuel is going to slam and separate when it hits that straight wall.
Good results so far. HP estimate for V8 HP=cfm x 2.06. Plenty of cylinder head so far. Looking forward to seeing what happens when you put the manifold on. Regards Greg
I wonder, if you make your texturing aligned with where the air wants to go, would that help flow. It helps induce swirl, when you swirl polish valves. It's probably quite tricky to align the burr in said direction.
I can't do that. What you are writing about is a shark tooth pattern. That would be great. Flows good forward and poorly backward. Impossible to do with a burr that I can see.
@servediocylinderheads Always fascinated by those cross rams from the first time I seen one. The Trick flow Ford EFI intake with the square truck ports are similar in design to them with those long runners and almost bet they dry flow more than most would think
Isn't 400+ SSR airspeed getting too high? I thought that too much SSR speed could block roof flow. I'm asking not criticizing. I love seeing all this MOPAR work
Yeah, with the small block mopars. Like I said, it would take as much work in opening up the truck kid rise dual plane as it eould the aftermarketn because they both need opening up. I spent a good 8 hours or so deep port matching and doing the plenum work on a stock mid 80s dodge 360 midrise dual plane. That was just to get all of the crosssections to be slightly larger than the crossection of the heads. Yhe edelbrock airgao if u remember was only something like 15-20 hp difference from a stock manifold at peak.. I also ported a 318/360 edelbrock performer intake and to get all the ports deep matched to a 318 gasket took about 8 hours as well. I also did a bunch of pleulnum work on that one as well.
