How much boost will a Magnusson make on a 402
I think the way to go on a Maggie is to move as much air as possible while keeping boost low. Roots superchargers get less efficient as boost goes up.
The standard MP112 at 14k rpm will intake just over 800 cfm at 10 psi, and something like 850 or so at 5 psi. At 90% volumetric efficiency a 402 at 6000 rpm would take in 842 cfm at 5 psi. Due to heating effects and other losses you'd actually see more than 5 psi, but that extra boost would be "wasted" - you'd still get no more than the 850 or so cfm worth of horsepower.
If it was me, and if there is clearance, I'd look at using the MP122 instead of the 112. I'd also work on reducing restrictions in the engine so that the air can move without as much boost (which is backpressure). I'd run a good-sized cam with moderate overlap. Something like a 232/240/115/111.
Just some thoughts.



