Ported Magnuson 2650 data:
I am all about sharing data as you know, we decided to try out a ported 2650 in place of my un-ported 2650. My setup is a forged stock C.I. bottom, stock heads, mmx HC1 cam, headers, 108tb, and full 3" exhaust. We went in thinking this would be an easy 50+ rwhp gain plug and play. What we didn't expect was to go the other direction with power. The consensus was potential of too much port for the setup. I strongly recommend that before you go down the road of porting, have a long conversation about what the expected outcomes for your particular setup will be. I am the first to provide this data publicly as far as I know and I hope it helps those who have these 2650's decide if it's the way to go. I've only heard quietly that these ports have made big power on 376c.i. setups, I know they have cranked out quite a bit of power on the 4xx motors, but for my particular setup, it was a no go.
The goal was to make bigger power with less pulley thrown at the blower, but we had to pulley down even more just to attempt to equal the power. We did do that, but had to drop to a 3.0 pulley with max rear overdrives to make 1hp more and use my "lighter" timing race tune to reach that goal. The decision was then made to put the old 2650 back on.
First graph below shows:
Red line un-ported 2650, blue line ported 2650.
Second graph below shows:
Blue line un-ported 2650 with 3.25 pulley and a lot of belt slip that was resolved, but you can see where power is going. Red line is ported 2650 with 3.0 pulley.
The rwhp lost and torque lost was quite surprising, but we have the data now and hopefully it's helpful to the group.
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