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I'm aware of the tuning difficulties of open
loop EFI - nothing like first hand experience. Of course it was mostly my own
fault in stubbornly persisting in trying to tune without proper instrumentation.
I think you might find that sticking with mechanical FI helps you in the
marketing department. The great majority of pilots who see my install are put
off by the reliance on electronics. Even a good friend/co-worker who is an EE
and specializes in control systems used in UAV applications questions the
reliance on electronics.
Just looking at the picture of Steve Thomas'
Mistral installation. Some of the hardware such as the intake manifold, if it
were readily available, would interest me. I contacted Mistral when I first
heard of them and couldn’t get the time of day from them. As a result my intake
was eyeball engineered and fabricated the
best I could given limited welding and machining skills. Hardware like this
would make this engine more accessible to more builders.
Mike Wills
Sent: Sunday, March 28, 2010 9:27 PM
Subject: [FlyRotary] Re: Turbo Planning and p-port planning
(Long)
Mike,
You misread me in this case. While I want to start with
simple pieces my hope is in another direction. My hope is for a full EFI or EMS.
For our use however simply using an EFI is not the answer. Something most people
are unaware of is the difficulty of tuning any non closed loop injection. This
is true of anybodies system. Tracy has done a fine job of producing a reasonable
EMS. The problem is most people are no better at tuning it than they were with
carburetors! This isn't a knock on the system, rather that most people aren't
good tuners. I'm holding out for direct injection myself. I'm not adverse to
electronics but I want a package In place that has an advantage over carburetors
in the first place.
Bill Jepson
Sent from my Verizon Wireless BlackBerry
From: "Mike Wills" <rv-4mike@cox.net>
Date: Sun, 28 Mar 2010 19:49:14 -0700
To: Rotary motors in
aircraft<flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Turbo Planning and p-port planning
(Long)
Thanks Bill. I saw the PSRU when I met Everett
and Alan in the mid 90s. It was a nice piece of equipment. The PP with
mechanical injection should be a good setup and should attract those who are
afraid of the EFI stuff.
Alas, unless I am misreading you, it doesn’t
appear that you are headed in the same direction I am. Tracy's stuff is working
for me (and others) and is proven. Would be nice to see you (or someone else
equally knowledgeable) fill in the gaps Tracy doesn’t address. An engine with
aluminum housings to replace the stock iron housings, properly engineered (and
dyno proven) intake and exhaust, etc.... And built to fit my airplane (if it
will fit an RV-4 it will probably fit anything).
Of course a fully packaged engine/psru ready to
bolt on probably makes sense from a marketing standpoint. Good
luck.
Mike Wills
Sent: Saturday, March 27, 2010 10:40 PM
Subject: [FlyRotary] Re: Turbo Planning and p-port planning
(Long)
In a message dated 3/27/2010 7:58:16 PM Pacific Standard Time, rv-4mike@cox.net writes:
Bill,
I'm sure you are right, less expensive is more
marketable. Same point I tried to make earlier. It was a joke.
Having said that, not sure I wouldn’t be
willing to pay a sizable amount (easy to say since its all hypothetical). The
thing is I've been thinking about a Harmon Rocket for a few years now. What
would it be worth to get HR performance without having to build an entirely
new airplane?
Since we are talking hypothetically, what would
that $25,000 engine look like? How much of it would be Mazda and how much
of it would be custom? If we were willing to split the difference and
essentially retain all the Mazda pieces except the iron housings are we
still talking about $25K? Just thinking out loud here.
Mike
Mike,
I understood the joke, and I am sorry to throw cold
water on it. The Superlite engine retained the Mazda trochoid housings but even
those were modified to remove as much weight as possible. They also went dry
sump and fed the water at the center housing out through the spark plug area.
The engine looked like the entire engine was the shape of the rotor housings
with all aluminum end plates and p-ports. The engine mounts were extended "ears"
on the end plates. The previously mentioned custom-built planetary on the
front and the pendulous damper on the rear. Also of interest was that it was
plugs up, and turned backward to achieve normal prop rotation! With exception of
the rotors and housings every part was custom including the
e-shaft.
They then came to their senses and built the iron eagle
engine. It looked like a regular 13B because it was. The PSRU is a nice one
using the internal ring gear and pinion, spur cut. I think it is one of the
better designs and a benefit is that it offsets the engine 2 inches
down which really helps cowl clearance. They also used a modified
aircraft certified mechanical FI with the standard leaning knob. I hope these
things can be saved and sold for a much lower price. It would help us all
tremendously.
Bill Jepson
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