In a message dated 1/23/2008 12:18:25 P.M. Central Standard Time,
Adam@ValidationPartners.com writes:
>he's right about
adding upper deck pressure to the injectors to increase the differential
pressure between MP and cowl pressure into >the
injector.
This is from TCM’s
“Continental Engine Theory” training manual. If you believe what TCM
says, we have all been barking up the wrong tree. The injector nozzle behaves
like the shower head in your bathroom. Fuel dribbles in big droplets at low
flow rates, and atomizes nicely at high fuel flows. The air bleed is there to
help with atomization at low power settings, which coincidentally provide lots
of pressure differential between MAP and ambient.
Adam,
Excellent excerpt.
Remember that when operating LOP at higher altitudes the fuel flow may be half
or less than that used at 100% power but 3 or 4 times that used at idle.
Also, remember that the engine manufacturer may assume, for NA
engines, that the absolute manifold pressure (MAP) is never
higher than the pressure available at the hole(s) in the injector. Ram
air, superchargers or turbo chargers change that relationship.
Note that the injectors in my
Lycoming engine have only one hole for the introduction of
air.
Some of us are not barking up the
wrong tree - we have seen the results of this "experiment."
Scott Krueger
AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL (KARR)
Pilot
not TSO'd, Certificated score only >
70%.