Actually, if memory serves Mistral's retail pricing was pushing $60k
before they went belly up......okay, maybe belly side
ways.....edging to up.
I have the Mistral intake and super pleased to have licked onto
having proper timing to get it. (Even though the fuel rail design
seems to have been part of the reason for my engine shut down last
month at about 800 feet over the airport)
It seems Mistral has some talented engineers without solid business
sense (or maybe just socialist business sense....perhaps one in the
same). To have a seemingly known market niche in am already limited
market and dismiss such does not seem to be a good business route.
Chris Barber Houston Velocity N17010
The experiment aviation market is very fortunate and lucky to
have a
low cost mass produced engine that is more durable than a $30,000
aircraft piston engine. They just don't know it yet.
The biz model that makes sense is buy the low cost engine from
Mazda
and buy the parts to turn it into an aircraft engine from some one
else.
Paul Lamar
Chris,
I sent you photos of my Mistral intake & fuel rail a while back.I
recall your engine loss report but can't remember reading about the
Mistral fuel rail as a factor in the episode. How did it contribute
to the stoppage and what remedial steps did you take to resolve the
problem with it?
Thanks,
Jack Hilditch
Jack, I don't think I posted about my engine out here. It happened
only last month. I think I posted on FlyRotary to let the word out.
Basically, on the first trip out of my home airport's pattern the
engine quite at around 800 feet over Pearland Regional Airport
(LVJ)
a few miles away from my base airport, Ellington (EFD). The engine
had been running well and strong and cool so I felt it was time to
expand my test envelope.
I got to LVJ much faster than I expected as I was use to
Cessna/Piper training types. My Data log shows I was at around 140
knt's (not sure if indicated or true....just don't remember) on the
short hop. I got there so much faster than expected I had to get my
bearings and started entering the pattern a bit off of
standard. As I
was reorientated, but still a little low of pattern altitude, I
throttled back slightly as I was turning onto downwind long
when the
engine quite.
My mind briefly thought to start hitting switches as practiced but,
uh, I was only about 800' agl, time was at a premium. So I
called on
the radio I lost the engine and I needed 32 (with the wind. 14 was
active). Heard a couple of verifications acknowledging my
traffic as
I flew the airplane down, fast. I past the numbers pretty close to
the deck and fast, I put down the speed brake for good measure and
luckily slowed as I flew down the 4300' of concrete. As soon as I
noted 80knts (landing speed) I put the bird down, using my legs as
anti lock brakes and coasted to the end to the taxiway without
incident.
A friend in his RV recognized me in the pattern and landed just
after
me (United pilot) and pulled up as I popped the door. Then a
greeting
party of airport types who were monitoring the radio come
pouring out
to make sure all was well.
After a few minutes of speaking to the airport folks, the engine
started back up, but was a little rough. I taxied to the ramp.
Upon inspection we (my mechanical engineer friend who owns an
aviation related business and is building an RV-7) found some
gunk in
the fuel rail. It looked to me that it was perhaps a bit of the
residue powder you get when you make a hose. Yes, I thought I had
cleaned this but as is obvious, must have missed it.
What seems to have happened is that the Mistral fuel rail uses a
very small orifice on the return end of the fuel rail to regulate
pressure. The gunk clogged this return orifice thus not
allowing any
fuel to return after the injectors, this backed up the fuel,
causing
a spike in fuel pressure (verified via the datalog) and
flooding the
engine and causing the engine to quite.
I have since enlarged the orifice in the Mistral fuel rail and it
returns to the fuel pressure regulator to control pressure.
There is
a bypass hose that goes around fuel pressure regulator that has a
plug in it with a similar orifice to give the fuel a way to flow
regardless.
Sorry if I went a bit long on the war story part.
Perhaps y'all can enlighten me why Mistral would use this
orifice as
the way to control fuel pressure as it is the proverbial single
point
of failure whereas the pressure regulator with bypass seems to
provide two viable routes. Yes, my hose should have been cleaner. I
think I had to remake the hose that goes into the fuel rail and
only
vaguely remember the actual process.
I have a hangar temporarily at LVJ where I was able to rework the
fuel return. I hope to get out there after work to continue the
efforts.
Chris Barber Houston
Chris,
Mistral didn't intend the orifice in the rail to control
pressure at all.
The intent was for there to be a regulator, with a manifold
pressure
correction. The small orifice was a means of preventing vapor
locks or
difficulty in priming if you ran a tank dry. The orifice lets
the air in
the line bleed out.
Bill Jepson
Chris,
Bill is correct. One trick to prevent what happened to you
is to
put a small piece of wire through the orifice, bent to about 45
degrees on both sides so it can't escape. The wire lets the
orifice
function, but prevents a particle from seating itself across the
orifice.
Aubrey Thompson
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