Today's Message Index:
----------------------
1. 05:13 AM - Re: MAP and RPM (was: range) (Brian Lloyd)
2. 05:22 AM - M14R Power (Richard Goode)
3. 05:25 AM - Re: MAP and RPM (was: range) (Brian Lloyd)
4. 05:37 AM - Re: In reply to Bill Halverson Richard Goode (Brian Lloyd)
5. 06:25 AM - Re: MAP and RPM (was: range) (Ernie)
6. 06:58 AM - Re: MAP and RPM (was: range) (Brian Lloyd)
7. 07:21 AM - Re: MAP and RPM (was: range) (Ernie)
8. 08:10 AM - Re: MAP and RPM (was: range) (cjpilot710@aol.com)
9. 08:10 AM - Re: Request from the Smoking Section..... (Dave Laird)
10. 01:14 PM - New Operating Limitations (cpayne@joimail.com)
11. 01:31 PM - M-14 Power Curves (cpayne@joimail.com)
12. 01:55 PM - Re: New Operating Limitations (Jon Boede)
13. 02:07 PM - Re: MAP and RPM (was: range) (Brian Lloyd)
14. 02:22 PM - Re: MAP and RPM (was: range) (cjpilot710@aol.com)
15. 02:56 PM - Re: New Operating Limitations (Robert Mortara)
16. 02:57 PM - Re: MAP and RPM (was: range) (Robert Mortara)
17. 03:52 PM - Re: MAP and RPM (was: range) (Brian Lloyd)
18. 04:55 PM - Re: MAP and RPM (was: range) (Bill Halverson)
19. 04:55 PM - Re: MAP and RPM (was: range) (Bill Halverson)
20. 05:02 PM - CJ6A mixture (Was: MAP and RPM) (Brian Lloyd)
21. 05:19 PM - Re: New Operating Limitations (Ernie)
22. 05:25 PM - Re: CJ6A mixture (Was: MAP and RPM) (Ernie)
23. 06:35 PM - Re: CJ6A mixture (Was: MAP and RPM) (Brian Lloyd)
24. 07:16 PM - Re: CJ6A mixture (Was: MAP and RPM) (Robert Mortara)
25. 11:07 PM - Long Range Fuel Tanks (egon)
Message 1
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Sam Sax wrote:
> That are in Israel is the Dead Sea basin (where the Jordan river
> end). Elevation -1200 feet.
That's it.
> Felt real weird flying a jet at 400 kt while the pressure altimeter
> indicating -800'... Engine seemed to like it though.
Fat air.
--
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
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
--> Yak-List message posted by: "Richard Goode" <richard.goode@russianaeros.com>
To the US Yak List
M14R Power
In reply to Gus Frazer.
Certainly if the engine is not changed in any way, then power is roughly proportional
to MP.
However for the M14R, the cam-disc is changed to allow more mixture into the engine.
Hence more power. Definitely a genuine figure, and not "rounding out."
Agreed, that you cannot turn the supercharger faster and use less fuel. What Vedeneyev
are saying is at the same power setting - ie the engine turns slower but
gives the same horse power and, within measurable differences gives the same
fuel consumption.
Yes, it is true to say that some M14PF run hot - this is because people won't adjust
the compensating jet to give the richness at full power operation that is
needed.
In terms of oil, the prime problem is that the stock oil cooler is marginal for
400-hp in hard aerobatic applications in hot weather. This is why Sukhoi have
gone to a larger oil cooler (as on the Su-26M3), which we are also now beginning
to use. However it is a major modification to install it being a fair bit
larger.
It is also worth saying that the Sukhoi oil cooler ducting is not brilliantly designed
for maximum airflow through the cooler.
Hope this helps.
Best regards
Richard
Richard Goode Aerobatics
Newport House
Almeley
Herefordshire
HR3 6LL
United Kingdom
Tel: 44 (0) 1544 322200
Mob: 44 (0) 7768 610389
Fax: 44 (0) 1544 322208
www.russianaeros.com
This message has been scanned for viruses and
dangerous content by the http://www.anti84787.com
MailScanner, and is believed to be clean.
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Dee Grimm wrote:
> --> Yak-List message posted by: "Dee Grimm" <deegrimm@cox.net>
>
>
> The 4360's as used on the C-97 had turbo superchargers providing boost above
> the engine driven internal compressor and there was no interface between the
> MAP and the RPM. It was all manually controlled by the flight engineer
> utilizing the throttle, a waste gate control and the torque gage (indicating
> the BMEP.)
There is an indirect relationship. When you reduce RPM or throttle position you
reduce exhaust gas volume by a proportion equal to the change in RPM. This
reduces turbine RPM, compressor RPM, and inlet flow correspondingly, for a net
decrease in MAP. This further reduces exhaust gas flow so you would get a MAP
decrease all out of proportion to the RPM reduction. This is called bootstrapping.
To keep it from happening the flight engineer has to have a deft finger
on the waste gate control whenever RPM or throttle are changed.
I like manual waste-gate controls for their simplicity. If you get rid of all
that compensating hardware you eliminate a bunch of possibility for failure.
The cost is increased cockpit workload for the pilot or the addition of a flight
engineer.
--
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 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: In reply to Bill Halverson Richard Goode |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Gus Fraser wrote:
> --> Yak-List message posted by: "Gus Fraser" <fraseg@comcast.net>
>
> Richard,
> Could you explain how increasing the MP to 1150mm gives 450 HP?
> ...
>
>
> Further its impossible to turn a supercharger faster and yet use the same
> fuel,
> ...
> I am just a poor physics major maybe I missed something :)
I guess we both must be slipping then Gus. I couldn't figure it out either.
Maybe they use a different specification for horsepower? They may be using metric
horsepower that is about 1% less than English mechanical HP but that still
doesn't look like a 1% difference to me. 1% would only be about 4 hp out of
400.
Is the bore and stroke of the engine the same? Increased displacement would increase
hp at the same MAP and RPM. A slight change to the crankshaft could accomplish
that without having to change the pistons and rods but it would require
modification to the barrel and/or head.
But the proof of the pudding would be to mount one in an airplane and do rate of
climb tests.
--
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 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
I thought you were never supposed to over square radials.
Ernie
----- Original Message -----
From: <cjpilot710@aol.com>
Subject: Re: Yak-List: MAP and RPM (was: range)
> --> Yak-List message posted by: cjpilot710@aol.com
>
> Something to note.
> When we fly the B-24 and B-17 at the Collings Foundation, we're very
careful
> about "back loading" the engines. We treat them tenderly. At $40,000 to
> overhaul either the P&W 1830 (B-24) or the W-1820 (B-17) times 4, well we
babied
> them big time. Both engines are have super chargers and turbo chargers
(via
> waste gate). The waste gates are disconnected on the B-17 but not the
P&W-1830
> on the B-24. In anycase we never pull more than 45"mp. We're not
carrying
> 8,000 (B-24) or 4,000 (B-17) pounds of bombs either. Just about every
take-off
> we use 2,700 rpm and 40" to 42"mp (= 600 gph). Our normal cruise is 2,000
rpm
> and 30" which give both aircraft about 200 gph in auto lean.
>
> We make our approaches at 2,000 rpm and NEVER LESS than 22"mp. We are
trying
> to keep the prop from driving the engine. These engines have no oil l
> ubrication holes on the 'anti-thrust side' of the master-rod. It does not
take many
> hours to ruin these engines, if you push the rpms up on the downwind while
> making your approach. The Wrights stand up a little better simply because
they
> have a little more metal on the mater-rod.
>
> Rule of thumb -' Always keep aleast 1 inch over rpm'. i.e. 2,200rpm mp>
23"
>
> 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 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Ernie wrote:
> --> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
>
> I thought you were never supposed to over square radials.
That is flat engines and that is an old wives tale. I wish I could find the person
who came up with that "square" BS and shoot him retroactively before he first
opened his mouth. Just look at the engine manufacturer's data and don't
worry about "over square" or "under square". That crap has scared more pilots
from properly running their engines than just about anything I can think of ...
except maybe mixutre management.
It is like the rich vs. lean of peak EGT operation. A bunch of engines in the
early Piper Malibu got trashed because the pilots didn't trust Continental to
be correct about running lean-of-peak.
--
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 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
I've heard that in flat engines it isnt an issue and that the rule came from
older round engines. Something analogous to going uphill in your car in high
gear at low speed. Now we all know we shouldnt lug the engine.
Ernie
----- Original Message -----
From: "Brian Lloyd" <brian@lloyd.com>
Subject: Re: Yak-List: MAP and RPM (was: range)
> --> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
>
> Ernie wrote:
>
> > --> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
> >
> > I thought you were never supposed to over square radials.
>
> That is flat engines and that is an old wives tale. I wish I could find
the person who came up with that "square" BS and shoot him retroactively
before he first opened his mouth. Just look at the engine manufacturer's
data and don't worry about "over square" or "under square". That crap has
scared more pilots from properly running their engines than just about
anything I can think of ... except maybe mixutre management.
>
> It is like the rich vs. lean of peak EGT operation. A bunch of engines in
the early Piper Malibu got trashed because the pilots didn't trust
Continental to be correct about running lean-of-peak.
>
> --
>
> 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 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: cjpilot710@aol.com
In a message dated 10/22/2003 9:59:03 AM Eastern Daylight Time,
brian@lloyd.com writes:
>
> It is like the rich vs. lean of peak EGT operation. A bunch of engines in
> the early Piper Malibu got trashed because the pilots didn't trust Continental
> to be correct about running lean-of-peak.
> Brian Lloyd
Brian is correct here. On the big radials, the flight engineers use to lean
to max EGT, than lean out some more to achieve a cooler temp. The EGT cooled
down, cylinder head temp went down, and you still had a lean and more
economical mixture (at least at PAA they did). If you remember before EGT gages
came
popular, you would lean out an engine until it ran rough. You than push in
the mixture control (on US engine) until the engine ran smoother. Guess which
side of peak EGT you were on?
Please don't ask me why the engine people (maybe the lawyers really) have the
manuals written to be on the rich side of max EGT.
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 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Request from the Smoking Section..... |
--> Yak-List message posted by: Dave Laird <dave@davelaird.com>
Mike Goulian Airshows had a web page that had his requirements for
airshows...including type of smoke oil to provide.
here is an excerpt:
<snip>
The smoke producing characteristic of oils vary so the correct oil must
be supplied to produce dense white smoke. The
preferred oil Cannopus Oil #13, is by far the best smoke oil. If
Cannopus is not available other paraffin based oils may be
used. Acceptable are listed below.
Cannopus Corvus Oil 13 or 519 Standard Oil Facto 39
Texaco Regal B Sun Oil Circle X
Shell Carnea 10 or 22 Union Oil Unax 105
Gulf Oil 370 Arco Duro-S 105
Exxon Faxam 40 Military #1010 Eng. Oil
<snip>
Also, I have heard of something called "Super Dri" which is supposed to
NOT gunk up the belly of your A/C.
The people who make it are at :
http://www.mdw-aviation.com/
They do it for model aircraft as well as full scale and have lots of
info related to smoke production on their site....
DISCLAIMER: My A/C does NOT have a smoke system... furthermore, I
don't have ANY experience with any aircraft that does...so don't ask me
any questions! I just had researched this stuff awhile ago and found
this stuff..... Hope it helps.
Dave Laird
CJ6A N63536 "Betty"
Dallas
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | New Operating Limitations |
--> Yak-List message posted by: cpayne@joimail.com
The deed is done, my aircraft is re-certified with fresh
Airworthiness Cert and all associated paperwork. The FSDO
guy had to see the airplane and logbooks. His reasoning was
that because a change in ops limits (moving) was made, this
requires "updates" to latest standards and homebase. A new
certifiction must be applied for as "Amended".
This procedure MUST occur for all moves, even if I move 4
miles away to LAL, in the same FSDO district. Whatever
restrictions are current in 8130-2x at time, you get.
Everything By-The-Book, (as they see it), not break'n new
ground here, too dangerous.
Apparently, due to all that has happened in the last 2
years, the FAA FSDO's have a whole slug of new people that
they don't know where to put. Maybe your airplane will be
next?
Craig Payne
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | M-14 Power Curves |
--> Yak-List message posted by: cpayne@joimail.com
Shame on you guys that have 400HP engines and don't know the
power, altitude and fuel consumption specifics! All you had
to do was stop by the George Coy/Aeromotors booth at either
OSH or SNF and pick up spec sheets on the various engines;
complete with power curves.
For those who care: the power curve v alt. for the 360HP
version is a straight line with 100% power at Sea Level and
about 237HP at 5500 Meters. The 400HP version carries about
275HP at the same altitude. Curves for lesser RPMs (at max
allowable throttle) are similar except for lower RPM
settings where there is a "blip" of power. 1000 Meters at
1860RPM and 1900 Meters at 1730 RPM.
Fuel consumption: 39GPH at WFO for the 360 and 43GPH or so
for the 400. During the SNF race where I run WFO for about
20 minutes I do experience something like this but it's hard
to tell without a fuel flow sensor and totalizer.
So how far will a 400HP standard fuel capacity Yak-52 fly at
WFO?
Craig Payne
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: New Operating Limitations |
--> Yak-List message posted by: "Jon Boede" <jon@email.net>
> --> Yak-List message posted by: cpayne@joimail.com
>
> Apparently, due to all that has happened in the last 2
> years, the FAA FSDO's have a whole slug of new people that
> they don't know where to put. Maybe your airplane will be
> next?
>
> Craig Payne
Any ponderings on where the aforementioned slug came from, and why?
Jon
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
cjpilot710@aol.com wrote:
> Please don't ask me why the engine people (maybe the lawyers really) have the
> manuals written to be on the rich side of max EGT.
That I can tell you. On the rich side of peak EGT, the power difference between
cylinders with different mixtures is less. Given that normally aspirated flat
engines with carburetors have horrible mixture distribution, you have to run
on the rich side of peak EGT for the engine to run smoothly.
In a radial engine with a mechanical supercharger like the Huosai and Vendeneyev
the fuel and air are sucked through the carburetor into the supercharger which
does an excellent job of vaporizing and mixing the fuel. The cylinders of
these types of engines get very even mixture distribution which allows you to
run on the lean side of peak EGT and still get even power out of all the cylinders
and thus smooth operation.
Running on the lean side of peak EGT generally results in cooler cylinders and
less combustion deposits for the same power output. If done right your engine
will actually last longer.
--
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 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: cjpilot710@aol.com
In a message dated 10/22/2003 5:08:02 PM Eastern Daylight Time,
brian@lloyd.com writes:
> >Please don't ask me why the engine people (maybe the lawyers really) have
> the
> >manuals written to be on the rich side of max EGT.
>
> That I can tell you. On the rich side of peak EGT, the power difference
> between cylinders with different mixtures is less. Given that normally
> aspirated flat engines with carburetors have horrible mixture distribution, you
have
> to run on the rich side of peak EGT for the engine to run smoothly
OK, that makes sense, I could not see the physics before i.e. like what's the
difference whether 25' cool cool or 25' hot cool? When we're talking temps
in the 1200 range, that an't a lot. But still think you can run smooth with a
cooler EGT on the lean side.
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 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | New Operating Limitations |
--> Yak-List message posted by: "Robert Mortara" <rob@robinhill.com>
After notifying the Faa when moving our CJ a year ago and with this years
notification they finally answered. What type of changes or problems should
I anticipate. Craig What changes were made to your operating limitations?
rob
Message 16
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | MAP and RPM (was: range) |
--> Yak-List message posted by: "Robert Mortara" <rob@robinhill.com>
Been running my Bonanza Lean of Peak for 1300 hrs even though the general
consensus 10 years ago the engine would not make another 50 hrs.The engine
went 250 over TBO to 1950 hrs (1700 TBO).I do have a JPI edm-700 and GAMI
balanced fuel injectors in the Bonanza.
What are you guys doing with the CJ engine. LOP ROP ? Low rpm in extended
range flight.? Any one use a engine monitor?
the posts on this issue is confusing?
rob
-----Original Message-----
From: owner-yak-list-server@matronics.com
[mailto:owner-yak-list-server@matronics.com]On Behalf Of
cjpilot710@aol.com
Subject: Re: Yak-List: MAP and RPM (was: range)
--> Yak-List message posted by: cjpilot710@aol.com
In a message dated 10/22/2003 9:59:03 AM Eastern Daylight Time,
brian@lloyd.com writes:
>
> It is like the rich vs. lean of peak EGT operation. A bunch of engines in
> the early Piper Malibu got trashed because the pilots didn't trust
Continental
> to be correct about running lean-of-peak.
> Brian Lloyd
Brian is correct here. On the big radials, the flight engineers use to lean
to max EGT, than lean out some more to achieve a cooler temp. The EGT
cooled
down, cylinder head temp went down, and you still had a lean and more
economical mixture (at least at PAA they did). If you remember before EGT
gages came
popular, you would lean out an engine until it ran rough. You than push in
the mixture control (on US engine) until the engine ran smoother. Guess
which
side of peak EGT you were on?
Please don't ask me why the engine people (maybe the lawyers really) have
the
manuals written to be on the rich side of max EGT.
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 17
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
cjpilot710@aol.com wrote:
>>That I can tell you. On the rich side of peak EGT, the power difference
>>between cylinders with different mixtures is less. Given that normally
>>aspirated flat engines with carburetors have horrible mixture distribution, you
have
>>to run on the rich side of peak EGT for the engine to run smoothly
>
> OK, that makes sense, I could not see the physics before i.e. like what's the
> difference whether 25' cool cool or 25' hot cool? When we're talking temps
> in the 1200 range, that ain't a lot. But still think you can run smooth with
a
> cooler EGT on the lean side.
It isn't the temperature, it is the mixture. We are just using the EGT to see
how close we are to an optimum stochastic mixture. Peak EGT occurs when you have
the optimum fuel:air ratio (or really close to it because this isn't a perfect
world). As you go on the lean side power drops off much faster as you have
a lean mixture than when you have a rich mixture.
For instance, a 1% difference in fuel:air ratio on the lean side may cause a 5%
difference in power whereas a 1% difference in fuel:air mixture on the rich side
may result in only a 1% difference in power. (I am making up these numbers
to make a point because I don't remember the exact numbers but the general gist
is correct.) So if your mixture is not even among all the cylinders, if you
are on the rich side of optimal mixture your cylinders will still be producing
about the same power. OTOH, if you can ensure that all your cylinders are
getting exactly the same mixture, you can run on the lean side and still have
even power from all the cylinders while taking advantage of more complete combustion
to extract all the power out of the fuel without any waste.
Running on the lean side means more efficiency and cleaner burning. It means fewer
combustion products in the oil from blowby and fewer deposits on the pistons,
heads, exhaust valves, and the belly of the airplane.
--
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 18
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Bill Halverson <william@netpros.net>
I seem to recall one being called ' best power ' and the other ' best economy '
Bill Halverson
At 02:21 PM 10/22/2003, cjpilot710@aol.com wrote:
>--> Yak-List message posted by: cjpilot710@aol.com
>
>In a message dated 10/22/2003 5:08:02 PM Eastern Daylight Time,
>brian@lloyd.com writes:
>
> > >Please don't ask me why the engine people (maybe the lawyers really)
> have the
> > >manuals written to be on the rich side of max EGT.
> >
> > That I can tell you. On the rich side of peak EGT, the power difference
> > between cylinders with different mixtures is less. Given that normally
> > aspirated flat engines with carburetors have horrible mixture
> distribution, you have
> > to run on the rich side of peak EGT for the engine to run smoothly
>
>
>OK, that makes sense, I could not see the physics before i.e. like what's the
>difference whether 25' cool cool or 25' hot cool? When we're talking temps
>in the 1200 range, that an't a lot. But still think you can run smooth
>with a
>cooler EGT on the lean side.
>
>Jim Goolsby
Message 19
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: MAP and RPM (was: range) |
--> Yak-List message posted by: Bill Halverson <william@netpros.net>
I seem to recall one being called ' best power ' and the other ' best economy '
Bill Halverson
At 02:21 PM 10/22/2003, cjpilot710@aol.com wrote:
>--> Yak-List message posted by: cjpilot710@aol.com
>
>In a message dated 10/22/2003 5:08:02 PM Eastern Daylight Time,
>brian@lloyd.com writes:
>
> > >Please don't ask me why the engine people (maybe the lawyers really)
> have the
> > >manuals written to be on the rich side of max EGT.
> >
> > That I can tell you. On the rich side of peak EGT, the power difference
> > between cylinders with different mixtures is less. Given that normally
> > aspirated flat engines with carburetors have horrible mixture
> distribution, you have
> > to run on the rich side of peak EGT for the engine to run smoothly
>
>
>OK, that makes sense, I could not see the physics before i.e. like what's the
>difference whether 25' cool cool or 25' hot cool? When we're talking temps
>in the 1200 range, that an't a lot. But still think you can run smooth
>with a
>cooler EGT on the lean side.
>
>Jim Goolsby
Message 20
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | CJ6A mixture (Was: MAP and RPM) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Robert Mortara wrote:
> What are you guys doing with the CJ engine. LOP ROP ? Low rpm in extended
> range flight.? Any one use a engine monitor?
Most people haven't a clue what is going on with the mixture in their Huosai engine.
Most CJ's have no engine monitoring and they just rely on the engine smoothness
to determine OK mixture. My CJ had a single-probe EGT which I deemed
acceptable for leaning because the mixture is consistent due to the supercharger
mixing the fuel and air. For full power operation I would run about 100 degrees
rich of peak (ROP). For cruise I would run about 10-20 degrees lean of
peak (LOP).
I did find LOP operation to be a problem until I got my carb adjusted properly.
Since the carb would vary the mixture as airflow changed, the engine had a tendency
to surge when running LOP. Tweaking the carb solved the problem. (Set
the idle mixture first then set the needle otherwise you won't ever get the
mixture constant over the range of throttle settings.)
EGT was very consistent and I could set the EGT to absolute values over a wide
range of power settings. When I was going cross-country I would carefully lean
to LOP.
As for RPM, I tend to run 2150 for doing acro and between 1850 and 2050 for cruise
depending on how much fuel I am willing to burn.
> the posts on this issue is confusing?
Does this help?
--
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 21
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: New Operating Limitations |
--> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
If you would have dealt with Bob Cunningham, he would have asked you to send
him the info and you would have had a new AW in the mail about 2 weeks
later.
Ernie
----- Original Message -----
From: <cpayne@joimail.com>
Subject: Yak-List: New Operating Limitations
> --> Yak-List message posted by: cpayne@joimail.com
>
> The deed is done, my aircraft is re-certified with fresh
> Airworthiness Cert and all associated paperwork. The FSDO
> guy had to see the airplane and logbooks. His reasoning was
> that because a change in ops limits (moving) was made, this
> requires "updates" to latest standards and homebase. A new
> certifiction must be applied for as "Amended".
>
> This procedure MUST occur for all moves, even if I move 4
> miles away to LAL, in the same FSDO district. Whatever
> restrictions are current in 8130-2x at time, you get.
> Everything By-The-Book, (as they see it), not break'n new
> ground here, too dangerous.
>
> Apparently, due to all that has happened in the last 2
> years, the FAA FSDO's have a whole slug of new people that
> they don't know where to put. Maybe your airplane will be
> next?
>
> Craig Payne
>
>
Message 22
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CJ6A mixture (Was: MAP and RPM) |
--> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
So based on your last post running LOP on a carburated flat engine would not
be a good idea. And concerning my Housai, since I rarely fly higer than 3000
ft I never touch the mixture lever.
Ernie
----- Original Message -----
From: "Brian Lloyd" <brian@lloyd.com>
Subject: Yak-List: CJ6A mixture (Was: MAP and RPM)
> --> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
>
> Robert Mortara wrote:
>
> > What are you guys doing with the CJ engine. LOP ROP ? Low rpm in
extended
> > range flight.? Any one use a engine monitor?
>
> Most people haven't a clue what is going on with the mixture in their
Huosai engine. Most CJ's have no engine monitoring and they just rely on
the engine smoothness to determine OK mixture. My CJ had a single-probe EGT
which I deemed acceptable for leaning because the mixture is consistent due
to the supercharger mixing the fuel and air. For full power operation I
would run about 100 degrees rich of peak (ROP). For cruise I would run
about 10-20 degrees lean of peak (LOP).
>
> I did find LOP operation to be a problem until I got my carb adjusted
properly. Since the carb would vary the mixture as airflow changed, the
engine had a tendency to surge when running LOP. Tweaking the carb solved
the problem. (Set the idle mixture first then set the needle otherwise you
won't ever get the mixture constant over the range of throttle settings.)
>
> EGT was very consistent and I could set the EGT to absolute values over a
wide range of power settings. When I was going cross-country I would
carefully lean to LOP.
>
> As for RPM, I tend to run 2150 for doing acro and between 1850 and 2050
for cruise depending on how much fuel I am willing to burn.
>
> > the posts on this issue is confusing?
>
> Does this help?
>
> --
>
> 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 23
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: CJ6A mixture (Was: MAP and RPM) |
--> Yak-List message posted by: Brian Lloyd <brian@lloyd.com>
Ernie wrote:
> --> Yak-List message posted by: "Ernie" <ernest.martinez@oracle.com>
>
> So based on your last post running LOP on a carburated flat engine would not
> be a good idea.
Right. But the engine will tell you because it will run roughly.
> And concerning my Housai, since I rarely fly higer than 3000
> ft I never touch the mixture lever.
As I said, most people don't know what is happening with the mixture so they do
what you do and leave a lot fuel behind.
The thing I find difficult to understand is why, after spending $75,000 or more
on an airplane many pilots are unwilling to spend another $200 for an EGT gauge.
--
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 24
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | CJ6A mixture (Was: MAP and RPM) |
--> Yak-List message posted by: "Robert Mortara" <rob@robinhill.com>
Ernie are you serious about never leaning you CJ?
I start leaning about 30 seconds after I start my engine. Full rich on take
off and start leaning after about 1 minute when I back down the throttle
and RPM mixture about 1/2.
In cruse my mixture is almost all the way forward. I find it hard to see the
EGT to tell if I am LOP or Peak a digital would be allot better.
rob
Message 25
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Long Range Fuel Tanks |
--> Yak-List message posted by: "egon" <egon@hinet.net.au>
G'day all. The other day I saw a neat set of under wing fuel tanks mounted on a Yak 52. They are still being certified down here in Australia but I believe the final product is not too far away. They were designed and fabricated by Lindsay Sinclair of Red Star Aviation. The idea is that no new holes are cut into the airframe and I believe they are quickly fitted or removed as required. Lindsay is about to put some details on his website if anyone is interested. www.redsteraviation.com.au/
Rgds.
Egon
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|