|
Why K-Jet is great:
Very simple design. Not many moving parts. Can accommodate some motor
changes without freaking out (different cam, larger pistons, etc).
Why K-Jet isn't great:
There's always some giant flap in the way of the air. Low RPM fuel
atomization isn't great. Slightly funky when integrated into an O2
sensor feedback system.
Lots of vendors, including volvo, stuck with k-jet everywhere they could
for as long as they could. They moved on to timed port injection for one
reason only -- emissions regulations. At low RPM/throttle settings, the
K-Jet system squirts a bunch of fuel into the intake port where it pools
up and then gets sucked into the chamber in one gulp when that valve opens.
That fuel won't get atomized as well as if the injector had squirted it into
the port right before the valve opened so you get higher emissions on the
K-Jet system. At higher RPM/loads, any system is going to have the injectors
running for long periods of time relative to how long the valve is open so
all of them have that k-jet behavior, unless you're talking about the cars
with injection systems that squirt a stream of fuel into the port instead
of injection systems that make atomized sprays of fuel.
For simplicity, though, the k-jet is darned good relative to its
complexity, and for this application, that's more important than emissions.
chris
|
