Bob,
Just to make sure we are on the same page, the things called "air bleeds" on this page:
http://www.mazdatrix.com/c-6.htm
As Ed pointed out, doesn't change the amount of fuel injected.
For emissions, the hardest part is transient changes of throttle and manifold wetting.
Spray fuel onto the manifold, and a wet puddle forms. So the mixture might be lean
as fuel puddles, but lift of the throttle and high vacuum helps suck in fuel. Nice and
rich for a few events. Neither are idea for emission reasons.
With aircraft engines at a steady rpm, not an issue.
So that is why the are there.
Tom Walter
From: Ed Anderson <eanderson@carolina.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Monday, August 8, 2011 11:13 AM
Subject:
[FlyRotary] Re: Injector Mixing Plate
Hi Bob,
I have flow with and without the plastic injector "mixing"
plates - I truly fully could not detect any measurable difference
with/without. The only thing I believe that might have been any
different with the plates - it seemed the engine started smoother and
quicker on colder mornings.
Since the mixing plate has no bearing on how much fuel is
injected, but simply is to ensure better mixing of the primary injectors spray
with the incoming air, I doubt they would make the engine run leaner.
They might possibly have some minor effect on airflow (a
tiny bit of a restriction) possibly causing some perturbation - but then that is
what it is intended to do in order to get quicker and better fuel
atomization. Since the primary injectors have such a relative short path
between injector in intake port - I suspect the Mazda engineers figured they
would get slightly better fuel mileage with them.
FWIW
Ed
Sent: Monday, August 08, 2011 10:33 AM
Subject: [FlyRotary] Injector Mixing Plate
I have a 1987 Mazda
Turbo 13B engine in my Mustang II kit plane. The primary injectors in the center
housing are stock Nippon Denso 550 cc peak and hold. Below each injector is a plastic insert
called a “mixing plate”, which presumably disperses the fuel coming out of the
injectors before entering the combustion chamber. I am wondering if the obstruction in
fuel flow caused by the grid on the mixing plate would make the engine run lean
at higher engine speed, such as 5,000 to 6, 000 rpm. If I used a different injector, such as
the RC 550 cc (which has a better spray pattern), can I eliminate the mixing
plates? What happens if I
keep the stock injectors and just remove the mixing
plate?
I welcome comments from
anyone on the list, but hopefully, racing Guru Lynn Hanover can shed some light
on my questions.
Thanks,
Bob J.
Rogers
N62BT