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Posted for "Ron and Marlene Brice" <ghost1934@netzero.net>:
Susan,
For most of us with the IO-550, and 7.5:1 pistons, at lean of peak
mixtures ONLY, the correct figure is 13.75 X Fuel Flow.
I think you may have written your notes wrong at the GAMI seminar,
unless you have closer to 8:1 pistons. With 8:1 pistons the figure at
LOP is closer to 14.7, my notes from the GAMI seminar actually say 15 X
FF for 8:1 pistons, but with 7.5:1 pistons, the formula is 13.75 X Fuel
Flow at LOP.
Source http://www.advancedpilot.com/course.html I am copying this message to Walter Atkinson (who is envious of our
Lancair aircraft, whoops sorry Walter, I didn't mean to go public with
that little slip, but....you'd love a sleek efficient and FAST Lancair
Experimental, as they all posses the "Heart of a Sport Plane, Soul of a
Rocket" !) and he will reply to me and tell me if I have misled anyone.
I just talked to him yesterday, about this subject in response to
another post on the lml yesterday, and I will copy his answer yesterday
below for all to see. I hope this helps.
The following was generated by Mark's post on the lml yesterday, and I
answered him offline and copied Walter Atkinson (please don't bug George
Braly at GAMI, he's spending all his free hours on the PRISM system so
we can have an alternative to getting rated power when the replacement
100LL fuel is jammed down out throats by the next democratic
administration, maybe we'll have another 4 years ?). You can see
Walter's comments also, then the original post from Mark on this same
subject at the very end of this message.
Safe and efficient flying to all !
Ron
-----Original Message-----
From: Walter Atkinson [mailto:walter@advancedpilot.com] Sent: Saturday, February 07, 2004 8:29 AM
To: ghost1934@netzero.net
Subject: Re: [LML] Horse power
Ron:
I'm very happy you enjoyed the class and I certainly appreciate your
kind comments. Walter (BTW, you got it all right, too! <g>)
Original from Ron Brice to Mark:
Good Morning Mark,
The first thing you NEED to do is call the GAMI folks to schedule
yourself for the GAMI Advanced Pilot Seminar
(http://www.advancedpilot.com/explore_001.htm) in Ada, Oklahoma. I
finally freed up my schedule enough to attend the middle weekend of
January, and it was the BEST seminar I, at 65, have ever attended in my
life, bar none..and I have been at some really good ones in my
professional lifetime. The Best $1000 I ever spent, period.
Horsepower calculation formulas depend upon the compression ratio of the
engine. I am assuming you have 7.5:1 pistons? If so, the formula for
HP on your engine is 13.75 times the fuel flow, or with your last
sentence below, would yield 68.75% of power, a power range where you
must really know what is happening inside your engine.
50LOP is not the best guide for all operations, you need the GAMI charts
and the understanding which will come together for you like the
aftermath of a lightning bolt. When you to attend, you will not only be
totally immersed in engineering data, but you will observe detonation
and pre-ignition, real time, on an engine run in their test cell.
Besides, you will be the envy of everyone there when you fly your IV-P
in for the seminar! Don't be dismayed when you hear..Lancair aircraft
are the worst baffled aircraft in existence! I was shocked, then I
learned a little about baffling, and what it does, and how the air
really flows through the engine. Again, I was shocked to see the
results. The GAMI folks are "writing the book" on baffling, along with
Walter Atkinson, and much that you have heard is BUNK!
When you fly out, you will use much different technique on climb, and
you will feel comfortable at cruise knowing your engine loves the
mixture you are feeding it. You will understand the importance of the
CHT/EGT relationship like you never did in the past. Your MAG DROP run
up technique will be forever changed, and you will learn how to do an in
flight mag check.
All this will allow you to cruise at the LOP or perhaps even near peak
EGT setting (depending upon % power, of course) that YOU NOW KNOW is the
place you want to be (operation goals considered), because YOU NOW KNOW
WHAT IS HAPPENING INSIDE YOUR ENGINE. Please be careful leaning until
you get to the GAMI seminar. There are many engine operating arenas you
MUST avoid, and the Continental manual, if followed, will convince you
to damage your engine, in spite of the fact that what you are reading in
the wording section contradicts what you will find in the engineering
(obviously the better of the two) charts in the latter part of the book.
The engineers know, but the clutz writing the manual doesn't! The
seminar was the best treatise I have ever witnessed in teaching climb
technique, something I was weak on, and really needed.
When you lean, you can possibly get in trouble if you are "leaning
through peak" to get to LOP, depending upon your % power and the
duration of your exploration of peak. You will learn how to do it the
other way around, that is, pulling the mixture back in one big pull past
peak, then leaning towards peak to find peak. I learned to do this prior
to getting to the GAMI seminar, but wasn't comfortable with the
technique until it was discussed in class and I understood "THE RED
BOX", an area you NEVER WANT TO BE.
Trust me, Mark, you will be, like me, an "evangelist on engine
operation" when you finish the seminar. SAVE THOSE ENGINES! And, just
like the local preacher, I am finding those who "don't want to listen",
and shall surely spend many $$$$$ on maintenance, or worse yet, a
casket, that would be unnecessary if they only listened!
HHMMM, maybe I should ask them for a commission (GRIN)?
Ron
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