It can depend on a couple things, The stock intake manifolds on the magnum
engines dont go straight into the heads, The air (or water) goes down to the
plenum (belly pan) then has to go back up through the runners to get to the
heads. This is an effect called "Ram Tunnelling" it is generally used to
create a smoother (although less powerful) power curve and to develop torque
beginning right off idle (although less torque throughout the curve) and I
think it lowers emissions as well.
It is conceivable that if too much water gets down the manifold it can
actually block the flow of air substantially.
Also some of the water may flash steam when it hits the plenum pan causing
some wacky effects to the vacuum lines connected to the manifold,and hence,
the computer reacts. We all know how sensitive the computer is to changes in
vacuum signals.
Another thing is that the 440 has way more cylinder volume to deal with the
water and isn't as greatly affected.
I'm sure there are lots of other technical reason, but these are the first
that come to mind and I'm not the expert or anything.
Anyway, my solution is: 408 stroker motor with M1 intake manifold.
John S
PS It is also not a good idea to pour tranny fluid down your manifold to
clean the valves if you have the magnum stock manifold or the M1 with MPI. It
does , however, work great for carburated vehicle and possibly for TBI system
witht the M1 type manifold.
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:02:44 EDT