Today's Message Index:
----------------------
1. 04:23 AM - Re: RU coming? (Brian Lloyd)
2. 04:39 AM - Re: Lean Vs. Rich (was MAP and RPM) (Brian Lloyd)
3. 04:43 AM - Re: Lean Vs. Rich (was MAP and RPM) (Gus Fraser)
4. 05:30 AM - gone again! (cjpilot710@aol.com)
5. 06:53 AM - The MAP/LOP/ROP/ROPA-DOPA Debate (Steve & Donna Hanshew)
6. 03:38 PM - Re: The MAP/LOP/ROP/ROPA-DOPA Debate (David Stroud)
Message 1
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--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
cjpilot710@aol.com wrote:
> --> Yak-List message posted by: cjpilot710@aol.com
>
> Brain,
> Are you heading this way? Inquiring minds wonder.
I got your voicemail last night. Sorry, I had turned off my cellphone for choir
practice and forgot to turn it back on again until later.
I didn't leave yesterday and may not be able to leave today. There is a trough
that originates down by Nicaragua and extends NE across Hispaniola and out into
the Atlantic. They keep forecasting "lines and clusters of thunderstorms,
tops to FL 550". They keep revising and adding new SIGMETs. There are some supercells
in there that look like bloody hurricanes in the satellite pix. For
some strange reason I just can't bring myself to fly through there without weather
avoidance equipment. Heck, I wish I had a kerosene burner that would get
me above the bulk of the cloud cover so I can see and avoid the towering Cu.
I guess I leave when I leave.
Come to think of it, I just can't think of anything I need to get to that badly.
But thanks for thinking about me! I will give you a follow-up call.
OK, you guys can start calling me "la la" and "girlie man" now. No ice water left
in these veins.
--
Brian Lloyd 6501 Red Hook Plaza, Suite 201
brian@lloyd.com St. Thomas, VI 00802
+1.340.998.9447 - voice +1.360.838.9669 - fax
GMT-4
Message 2
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| Subject: | Re: Lean Vs. Rich (was MAP and RPM) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Walt Lannon wrote:
> --> Yak-List message posted by: "Walt Lannon" <lannon@look.ca>
>
> Thanks for a very timely and accurate explanation of the LOP/ROP question.
>
> With regard to radial engines only (with their close to optimum mixture
> distribution) it is fair to say that LOP operation is perfectly acceptable.
If they suck the fuel through the carb into the supercharger to mix the fuel-air,
yes. There are some radials like the Kinner (disclaimer: I'm answering this
from memory and I may be wrong) that don't have a blower and they suffer from
mixture distribution problems just like flat engines.
> As mentioned by other posters this was standard operating procedure for all
> airlines in the good old days of round engine airliners. I think this was
> referred to as "best economy" and though operating at slightly less than best
> power resulted in lower seat/mile costs with no detrimental effects to the
> engines.
Right.
> The CJ6 throttle/mixture system is a direct copy of the British standard
> that provided a "safe" method of throttle operation to prevent an
> inadvertent excess lean condition with throttle reduction (ie: throttle
> back enriches mixture). Probably thought to be prudent for training and
> combat operations. This is one of the major differences between the T6 and
> Harvard versions of the outstanding North American trainer of WW2.
> The Harvard uses the British mixture control of "rich - aft' but with a
> removable latch to accommodate the idle cut-off feature of the American
> carburettor (in British carburettors this was a separate control). This
> movable latch also allows mixture adjustment ahead of the throttle. Having
> flown the Harvard for more than 25 years and with an EGT gauge installed I
> have found that up to approx. 10,000 ft. the mixture control on the throttle
> stop will yield an EGT of 25 to 50 degs.F ROP.
The funny thing about that setting, i.e. 50F ROP, is just about the worst one for
the engine as it results in highest temperatures.
> I used to fine tune it ahead
> of the throttle to LOP to optimize fuel consumption but found it wasn't
> worth the trouble and the constant attention needed with any altitude
> changes.
But if you are going cross-country at the same altitude until letdown, it works
quite well. And with only 42 gallons in the tanks, every gallon you save is
one you can use later when your flight plan comes to naught and you have to do
something different.
> Whether the CJ system works as well I don't know (since my own is still a
> hangar queen and the others I have the opportunity to fly are mostly short
> flights) but I suspect it is very dependent on the correct adjustment of the
> carburettor and therefore may vary greatly between aircraft.
You are correct. When I first tried LOP operation I had a surging problem which
I cured by adjusting the carb. With the mixture control left in place the mixture
would get progressively richer as I retarded the throttle so I reset the
idle mixture and the needle to get a more uniform mixture as I changed the throttle
setting. That cured the surging problem.
BTW, if you don't have an EGT you can use CHT. It just takes a lot longer to finally
get the mixture set properly.
> What is the point of this diatribe? Beats the hell out of me but maybe it's
> just to say fly safe, if you want to save fuel do it right. Make sure your
> carb. is properly adjusted and you know how to lean correctly, particularly
> if you have removed the mixture/throttle stop.
But that is the way of all things. I believe in understanding the systems, their
capabilities, and limitations. Sure you can give students a rule-of-thumb
that will keep them out of trouble but my take on it is that you find out what
the student is capable of and then teach to that level. Flying is a complex
art. The machines we operate are complex machines. We shouldn't try to make
them out to be any simpler than they are.
--
Brian Lloyd 6501 Red Hook Plaza, Suite 201
brian@lloyd.com St. Thomas, VI 00802
+1.340.998.9447 - voice +1.360.838.9669 - fax
GMT-4
Message 3
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| Subject: | Lean Vs. Rich (was MAP and RPM) |
--> Yak-List message posted by: "Gus Fraser" <fraseg@comcast.net>
Sadly, Concorde just left JFK for the last time, looked great as usual.
Enough said.
Gus
Message 4
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keith.goolsby@eds.com, gaf127enl@msn.com, MDSHELLEY@aol.com,
yakjock@msn.com, walterfricke@yahoo.com, finleycj6@juno.com,
BDorsey777@aol.com, dabear@damned.org, Swifty305@aol.com,
tcalloway@datatechnique.com, mason.t@worldnet.att.net,
wpairprt@tdstelme.net, radialpower@cox.net, FamilyGage@aol.com,
rvfltd@televar.com, cd001633@mindspring.com, ernest.martinez@oracle.com,
FOUGAPILOT@aol.com, N23GD@yahoo.com, jtobul@tobul.com, KILOUSMC@aol.com,
davedris@cavtel.net, pino1@compuserve.com, RAre406906@aol.com,
JGoolsby@umaryland.edu, artziggy6@yahoo.com, vicky@shippei.com,
paraisoam@surfbest.net, EdrisDee@aol.com, Ckelso17@earthlink.net,
Csvanschaick@aol.com
--> Yak-List message posted by: cjpilot710@aol.com
Kids, Family, and Troops
Off again to fly the bombers and visit grandkids.
If you need to - my cell phone is 386-503-9820
I'll be back on Nov. 9.
Jim Goolsby
"They that can give up essential liberty to obtain a little safety,
deserve neither liberty nor safety"
Benjamin Franklin 1759
"With my shield, or on it"
Trojan Warriors BC
"The reason older men are like fine wine. When young, they are like grapes
until some woman stomps all over them."
Unknown older man.
Message 5
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| Subject: | The MAP/LOP/ROP/ROPA-DOPA Debate |
--> Yak-List message posted by: "Steve & Donna Hanshew" <dhanshew@cinci.rr.com>
For what it's worth. I have operated our CJ close to 11 years on the same engine,
which is fast approaching 1100 TT. It still compresses in the high 70s and
drips about as much oil as It did when I started flying it. Shortly after meeting
Randy Webb at a formation clinic in Geneseo, he suggested running at 5.5 and
1900-1950 with aggressive leaning in cruise. I had always leaned on the ground
just after start up to keep the plugs unloaded, but never to the extent he
suggested at cruise. I had tried to decipher all of the Chineses gibberish posted
on the quadrant and around my cockpit, but I had about as much success as
ordering at Lee Fong's restaurant. I said to myself, "What the Hell", so I followed
Randy's procedures at altitude and guess what - much improved performance.
I've never had an EGT on the plane, but by using Mr. Webb's gouge I saw 165 on
the CHT, 55 on the inlet oil, 95 on the outlet side, and a subsequent fuel burn
of 11.9 gph and what's more, my engine ran on the "sweet spot", I.e., little
to no vibration and stabilized setting that maintained itself. My goal was to
get the fuel burn down and keep the plugs clean. The results were both. Instead
of dropping the plugs every 20 hours I was able to go 50 hours to cleaning
and honestly, they weren't all that bad.
When I'm at cruise at, let's say, 6-8000 ft (I'm a lowly Buckeye flatlander) my
mixture is almost at the forward stop coincidental to 5.5 and 1950. So I guess
this confirms much of what has been bandied about over the past week. It is
fairly simple, ONCE you figure out the correct procedure. I guess you could take
a kneeboard and 40 gallons of avgas up to altitude and plot data points all
day long and then come down and crunch them in a spread sheet and make a nifty
set of endurance and range charts. In my estimation, that would be akin to working
on a cornplow with a jeweler's hammer.
My experience shows every engine is different, even the ones of the same block
number coming out the door shaft to case. What works on one may not on another.
Each one has a optimal operating peak that, without hamfisting, will seek itself
with some external assistance. There is a little test flying involved (although
I never bothered, because I didn't have the time) and analytical instruments
do help such as EGTs.
Hey, I'm not endorsing what I do, but it works for me.
Message 6
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| Subject: | Re: The MAP/LOP/ROP/ROPA-DOPA Debate |
--> Yak-List message posted by: "David Stroud" <davestroud@rogers.com>
Nicely said Steve and very encouraging for someone new to round engines. What fuel
are you burning? Thanks.
Dave Stroud, Ottawa, Canada
Christavia Mk 1 C-FDWS
Fairchild 51, early construction
----- Original Message -----
From: "Steve & Donna Hanshew" <dhanshew@cinci.rr.com>
Subject: Yak-List: The MAP/LOP/ROP/ROPA-DOPA Debate
> --> Yak-List message posted by: "Steve & Donna Hanshew" <dhanshew@cinci.rr.com>
>
> For what it's worth. I have operated our CJ close to 11 years on the same engine,
which is fast approaching 1100 TT. It
still compresses in the high 70s and drips about as much oil as It did when I started
flying it. Shortly after meeting Randy
Webb at a formation clinic in Geneseo, he suggested running at 5.5 and 1900-1950
with aggressive leaning in cruise. I had
always leaned on the ground just after start up to keep the plugs unloaded, but
never to the extent he suggested at cruise. I
had tried to decipher all of the Chineses gibberish posted on the quadrant and
around my cockpit, but I had about as much
success as ordering at Lee Fong's restaurant. I said to myself, "What the Hell",
so I followed Randy's procedures at altitude
and guess what - much improved performance.
>
> I've never had an EGT on the plane, but by using Mr. Webb's gouge I saw 165 on
the CHT, 55 on the inlet oil, 95 on the
outlet side, and a subsequent fuel burn of 11.9 gph and what's more, my engine
ran on the "sweet spot", I.e., little to no
vibration and stabilized setting that maintained itself. My goal was to get the
fuel burn down and keep the plugs clean. The
results were both. Instead of dropping the plugs every 20 hours I was able to go
50 hours to cleaning and honestly, they
weren't all that bad.
>
> When I'm at cruise at, let's say, 6-8000 ft (I'm a lowly Buckeye flatlander)
my mixture is almost at the forward stop
coincidental to 5.5 and 1950. So I guess this confirms much of what has been bandied
about over the past week. It is fairly
simple, ONCE you figure out the correct procedure. I guess you could take a kneeboard
and 40 gallons of avgas up to altitude
and plot data points all day long and then come down and crunch them in a spread
sheet and make a nifty set of endurance and
range charts. In my estimation, that would be akin to working on a cornplow with
a jeweler's hammer.
>
> My experience shows every engine is different, even the ones of the same block
number coming out the door shaft to case.
What works on one may not on another. Each one has a optimal operating peak that,
without hamfisting, will seek itself with
some external assistance. There is a little test flying involved (although I never
bothered, because I didn't have the time)
and analytical instruments do help such as EGTs.
>
> Hey, I'm not endorsing what I do, but it works for me.
>
>
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