Morning, Rusty. It is unlikely
that the EC-2 would respond to this pressure increase given where it occurs
and its short duration. The big pressure increase effect is
fairly localized in the runners. Remember this is a pulse of energy not
a slug of air. While unobstructed traveling down the tube, very
little of this energy is converted to pressure, However, when it reaches the
end of the runner, the kinetic energy of the Mach 1 wave is converted to
dynamic pressure. These pulses (Finite-Amplitude Waves) have been
measured as creating overpressure ratios of 1.5 - 2.0 that is from 21-30 PSI
absolute. After seeing what the exhaust FAW did to my stainless steel
fish tails on my exhaust (fragmented them in a few minutes, just fatiqued the
metal to the point that chucks fell out), I am a believer. Incredible
strong, but unfortuantely - just as incredible short in duration
{:>)
However, getting to the point of your
question - not to worry. It has no significant effect on the Air/Fuel
mixture. It is not as if this energy wave is pushing a fresh batch of
air into the equation (without compensating with more fuel ) and therefore
upsetting the A/F ratio. Rather, view it as simple a mechansim for
ensuring that more of the air/fuel mixture already there at the intake
port gets into the chamber each time it opens.
Hope this helps.
I see you have a new cowl on order. I
was wondering exactly what configuration for cooling do you have in
mind? I presume the two evaporator core approach is just not
configuration compatible with all you need to put under the cowling. One
thing, my brief experiment with reducing the inlet size by 33% tells me, is
that contouring the flow from inlet to radiator does indeed make a significant
difference in cooling performance.
Hang in there. I know about the
harassment you take from the Lycoming guys. But who really cares, they
pay their outlandish prices for 1932 technology and think they have a great
deal. Nothing wrong with a Lycoming as an aircraft engine except its
price, reliability, price, maintance cost, price, etc..
I now have more hours behind a rotary than
a Lycoming (about 400 total with 220 behind the Rotary), which I consider a
milestone {:>)
Ed Anderson