NC Engine Builder
Grumpy Old Man
- Joined
- Oct 10, 2008
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Extremely valuable information being discussed here, thanks guys!
The manifold being attached is effectively plugging off an area of the port, which is allowing the air to stay attached at the SSR to a slightly higher lift, which is how the gain is realized.
Years ago, I was porting some Indy 360-1’s that nosed over at high lifts.
If I just stuck my finger across the bottom of the radius inlet entry it would calm the port/SSR right down.
I had the customer send the intake to me, and as I remember it, the flow at higher lifts(after the point where the SSR was giving up) was higher with the manifold on vs off.
My .02 about the 5th cut is…….. for the application the heads will be used on, it was a step backwards.
I bet both columns have the about same peak at around 276, but in column A it’s happening either just before or just after 0.600 lift. In both columns the ‘crash’ occurs when the velocity over the SS reaches the same number. The manifold does change how the air is moving through the port so there would be SOME differences.Here’s what I’m seeing from that last video……..
The manifold attached to the head helped stave off the onset of the SSR going turbulent by about another .050-.100” of lift, which allowed a little spike in flow to show up.
But aside from that the intake being attached was causing a flow loss……as you’d expect.
From his flow sheet-
A-head only
B-intake mounted
Lift———A/B
.400—238.4/234.2
.500—269.0/251.6
.600—272.0/265.2
.700—269.6/276.0
.800—268.0/255.7
.900—271.2/255.0
Avg —264.7/256.2
I very much agree with this. I would really like to dyno test the same head ported 2 different ways. One would be focusing on mid lift flow with a moderate crash or stall at 0.600 lift. Next would be the same port with the short turn worked a little more to eliminate the crash or stall. Port 2 would have the prettier curve and a higher peak. Port 1 would have more 0.350-0.550 lift. My money would be on port 1 for the very reason you suggested. If we do a good job getting air in early the depression is not 28 inches at max lift. So in the running engine does the flow really crash?Also, it’s my opinion and since I did testing this way that around .400 lift or so the pressure drop on the port isn’t 28 inches.
I tested different lifts at different pressures because testing .100 lift at 28 inches is much lower than the port sees when running and 28 inches is too high for over .
I very much agree with this. I would really like to dyno test the same head ported 2 different ways. One would be focusing on mid lift flow with a moderate crash or stall at 0.600 lift. Next would be the same port with the short turn worked a little more to eliminate the crash or stall. Port 2 would have the prettier curve and a higher peak. Port 1 would have more 0.350-0.550 lift. My money would be on port 1 for the very reason you suggested. If we do a good job getting air in early the depression is not 28 inches at max lift. So in the running engine does the flow really crash?
I know you like the 50 degree seats and I’m not arguing that. I’d like to test that as well. On the flow bench the 45 degree seats naturally create a good port number 1. 50 degree seats naturally make a port number 2. The mix and match game would be fun.
is the candles and the widths of them.
hemi dong beater stuff.
Would you please have your wife translate this into East Tennessee English? Especially the first one and the last one. Not sure I want to know about the middle one.on my pump and see what happens.
Would you please have your wife translate this into East Tennessee English? Especially the first one and the last one. Not sure I want to know about the middle one.
Of the few builds out there the magnum edelbrocks seem to dyno slightly better then the LA ones.Just flowed an Edelbrock Magnum head, so here it is added to the flow results posted earlier. I bought this head as a blemished head and it had no valve job. I put a 35/45/60/75 valve job in and did a light blend of the sharp factory ridges in the throat. This should make the Magnum much like the ProMaxx and the AFR. The Speedmaster valve job is not as good as the other three. I was a little surprised by the results.
View attachment 1716455667
View attachment 1716455668
Yes, chamber is different. SSR is similar in the center but the corners are different. This is not just a copy of the LA head. It is an entire redesign.The chamber is quite a bit different isn’t it?
How similar is the SSR to the non-magnums?