Today's Message Index:
----------------------
1. 08:25 AM - Re: Batteries (A. Dennis Savarese)
2. 08:35 AM - Re: Re: Cowl design and CHT (A. Dennis Savarese)
3. 09:26 AM - AK-14P carburettor (Richard Goode)
4. 09:42 AM - Re: Batteries (Warren Hill)
5. 11:13 AM - Re: AK-14P carburettor (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E)
6. 11:32 AM - Re: Cowl design and CHT (Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E)
7. 11:40 AM - Re: Re: Cowl design and CHT (A. Dennis Savarese)
8. 03:38 PM - Re: Cowl design and CHT (Eric Wobschall)
9. 05:00 PM - Things that make you go Hmmm (Cpayne)
10. 11:46 PM - Re: Gear door (Nanchang CJ6)
11. 11:57 PM - Re: Worldwide Warbirds seeking inventory (Nanchang CJ6)
Message 1
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Tom, you can find the same size batteries at a local Batteries Plus or similar
store. Doesn't have to be the ELT brand.
Sent from my iPhone
On Oct 10, 2010, at 9:54 PM, Thomas Smith <thomas_csmith@yahoo.com> wrote:
>
> I'm told that ELK-12180 batteries fit a Yak 52, but I can't find any locally.
What can anyone recommend that can be had at Walmart, Advance Auto, Auto Zone,
etc?
>
>
>
>
>
>
>
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| Subject: | Re: Cowl design and CHT |
Different stroke lengths-yes. SEVERAL mm - no. Check the specs in the M14 maint
manual. Dennis
Sent from my iPhone
On Oct 10, 2010, at 8:38 PM, "Vic" <vicmolnar@aol.com> wrote:
>
> Hello,
>
> another thing to keep in mind : In a radial engine you have different stroke
for each piston, in fact several millimeters difference in the M14. So you have
different compression ratios as well. This will have some effect on power and
temperature for each cylinder. But then, this should concern cylinders with
some of the longest strokes to run hotter than the rest. Maybe this fact gets
clouded by some other effects still unreflected.
>
> Vic
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=315298#315298
>
>
>
>
>
>
>
>
>
>
Message 3
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| Subject: | AK-14P carburettor |
AK-14P carburettor
I have to repeat that I am NOT an expert in these carburettors 'but I
have
been involved with them for almost twenty-five years. Some points:
=D8 Although not an expert I have seen experts tuning the carburettors
and
the differences can be dramatic. This is why it is disappointing that
so
many people continue to fly with the carburettors as they bought the
aircraft, making no effort to improve them. There is such a world of
difference between a really well set-up M14P and a poor one!
=D8 Reading the different inputs on this topic, it does seem to me that
many
owners either do not have the detailed engine manual OR have not
bothered to
read it.
=D8 There is an extremely detailed technical description of the
carburettor;
how it works; and how to tune it.
=D8 BUT this is not for the inexperienced. The adjustments are VERY
interdependent; the amount of individual adjustment can be incredibly
small.
=D8 The compensating jet (as I said before) what the Russians call the
=93suction jet=94 is NOT the main fuel jet.
=D8 However the compensating jet affects fuel consumption (and very
importantly CHT) at all power settings ' i.e. from low-cruise to full
throttle.
=D8 As people have pointed out, CHTs can vary hugely depending on which
cylinder. This is particularly important in aircraft doing high powered
and
zero air speed manoeuvres, like torque-rolls. In this case the cylinder
that is to the left of the engine sump (as you look at the engine from
the
front) has most of the air-flow from the prop blanked, so will run very
hot.
=D8 In any case a JPI instrument showing ALL CHT=92s is clearly a good
idea.
=D8 One of the best exponents of this carburettor was the late and
much-missed Alex McLean in Spain.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Herefordshire
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
<http://www.russianaeros.com> www.russianaeros.com
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Tom,
I went to Batteries Plus and found a nice, small 12 v gel battery that is a perfect
sideways fit into the original Chinese battery box for the CJ-6A. Two sets
are connected in series and those two sets of two are connected in parallel.
GIves twice the voltage and twice the current of each one individually. Also,
you can check each battery individually. If one is going bad, you don't have
to replace all four. The extra weight at that station has also helped a little
to shift my CG a little aft. Always a problem with the CJ after all of that old
radio equipment has been removed.
Warren Hill
N464TW
On Oct 11, 2010, at 8:19 AM, A. Dennis Savarese wrote:
>
> Tom, you can find the same size batteries at a local Batteries Plus or similar
store. Doesn't have to be the ELT brand.
>
> Sent from my iPhone
>
> On Oct 10, 2010, at 9:54 PM, Thomas Smith <thomas_csmith@yahoo.com> wrote:
>
>>
>> I'm told that ELK-12180 batteries fit a Yak 52, but I can't find any locally.
What can anyone recommend that can be had at Walmart, Advance Auto, Auto Zone,
etc?
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
>
Message 5
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| Subject: | AK-14P carburettor |
Richard, you said:
=D8 The compensating jet (as I said before) what the Russians call the
"suction jet" is NOT the main fuel jet. However the compensating jet affe
cts fuel consumption (and very importantly CHT) at all power settings - i.e
. from low-cruise to full throttle
Please understand that I am not trying to debate the fine points of what a
certain part is called. The Russians call this a suction jet. Others call
it a "compensation jet" which (I think) actually comes from what it is d
oing inside the carb in order to cause the actual change in fuel delivery.
I called it a "Main Jet" simply because in most NORMAL carbs (meaning the
kind that are bowl and float types) the MAIN JET impacts the delivery of fu
el across the whole RPM range of the engine once it gets above idle, which
is exactly what the "suction jet" causes to happen. While it is indeed NOT
THE MAIN JET as you say, to those that work on engines other than this one
, you can think of this adjustment impacting the engines performance exact
ly as the MAIN JET normally would in a normal carb. The suction jet is not
, however, actually flowing the fuel which is why . yes. you are correct .
it is not the MAIN JET and I stand corrected. technically.
More and to the point, I would really appreciate it if someone ran through
a step by step explanation of how this thing works. It is one thing to rea
d a Task Card translated from Russian and then try to apply it, when the co
st of making a mistake is possibly a ruined engine, or at least one that re
quires a re-build. Which is why no one really wants to mess with these thi
ngs without knowledge and experience. This is a perfect Catch-22 since in
order to gain knowledge and experience you have to actually DO IT.
Yep, I have read everything I can get on this unit and understand that a lo
t of the flow and reactions are controlled by diaphragms and air bleeds. S
ome of these bleeds are the ones we are looking at now. The manual for thi
s puppy dog does indeed talk about how to adjust it, but it sure as blazes
does not go into a good explanation of how it actually works. I like to un
derstand theory before attempting practical application. Comes from doing
the job I do professionally.
Below is Task Card 205. It tells you exactly how to adjust the suction jet
.
Task Card 205
1. Check operation at all ratings on the initial adjustment starting form t
he take off rating Ref 072.00.00 Task Card 202
Note: If engine operates poorly at separate ratings, adjust the carburetor
.
2. Adjust fuel consumption at take off and nominal ratings using the follo
wing procedure:
(1) Unlock and undo suction jet plug (2) Ref. Fig 202)
(2) Select and replace the suction jet.
Note: It is allowed to install jet diameter 1.3 to 2.0 mm. Increasing the
jet diameter leans out the mixture, decreasing it, enriches the mixture.
The jet diameter change of 0.05 mm changes specific fuel consumption at tak
e off rating for 2 to 5 g/hp-h.
(3) Install and lock suction jet plug (2).
3. Adjust the engine in cruise rating II using the following procedure: (1
) Unlock metering needle adjustment screw (4) Ref: Fig. 201)
(2) Turn adjustment screw (4) to the required, aide to obtain the desired f
uel consumption
Notes:
1. Adjust the carburetor on the shutdown engine. Rotating the shaft clock
wise enriches the mixture and vice-versa.
2. Turn the metering needle screw up to the limit stops in either direction
from the initial setting.
3. The adjustment range to stop is eight clicks. One click of the metering
needle adjustment shaft changes fuel consumption from 4 to 8 /hp-h
4. Start the engine and check engine operation at cruise rating I and nomin
al rating II (Ref 072.00.00 Task Card 202) since the change in metering nee
dle position affects fuel consumption. 5. Perform additional adjustments w
ith the metering needle screw in case of deviations at cruise I rating and
nominal rating II.
Caution: Never turn the metering needle adjustment screw beyond the stops.
Otherwise previously adjusted fuel consumption for take off, nominal rati
ngs I and II would be abruptly changed and carburetor initial setting could
not be adjusted.
End Task Card 205 Quote Unquote Good luck.
From: Richard Goode
Sent: Mon 10/11/2010 12:23 PM
Subject: Yak-List: AK-14P carburettor
AK-14P carburettor
I have to repeat that I am NOT an expert in these carburettors -but I have
been involved with them for almost twenty-five years. Some points:
=D8 Although not an expert I have seen experts tuning the carburettors and
the differences can be dramatic. This is why it is disappointing that so
many people continue to fly with the carburettors as they bought the aircra
ft, making no effort to improve them. There is such a world of difference
between a really well set-up M14P and a poor one!
=D8 Reading the different inputs on this topic, it does seem to me that ma
ny owners either do not have the detailed engine manual OR have not bothere
d to read it.
=D8 There is an extremely detailed technical description of the carburetto
r; how it works; and how to tune it.
=D8 BUT this is not for the inexperienced. The adjustments are VERY inter
dependent; the amount of individual adjustment can be incredibly small.
=D8 The compensating jet (as I said before) what the Russians call the "su
ction jet" is NOT the main fuel jet.
=D8 However the compensating jet affects fuel consumption (and very import
antly CHT) at all power settings - i.e. from low-cruise to full throttle.
=D8 As people have pointed out, CHTs can vary hugely depending on which cy
linder. This is particularly important in aircraft doing high powered and
zero air speed manoeuvres, like torque-rolls. In this case the cylinder th
at is to the left of the engine sump (as you look at the engine from the fr
ont) has most of the air-flow from the prop blanked, so will run very hot.
=D8 In any case a JPI instrument showing ALL CHT's is clearly a good idea.
=D8 One of the best exponents of this carburettor was the late and much-mi
ssed Alex McLean in Spain.
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Herefordshire
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com
Message 6
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| Subject: | Cowl design and CHT |
I really do not feel qualified to advise you on any of this. If you are as
king for my OPINION... well... ok.
The slight hesitation when adding power on final can probably be cured by c
hanging the size of the Acceleration Pump jet. However, I would not do thi
s if you plan on messing with other adjustments. I'd do it last. However,
I WOULD mess with this one. It's easy and the change will be felt immedia
tely when you go flying and you are not messing with fuel ratios. Just fue
l delivered when the throttle is moved.
I trust Vladimir Yastremski and Dennis and realize fully that both of them
have more knowledge and experience on this engine than I probably ever will
have.
But if you want to go on .......
Before even thinking of adjusting your carb, make absolutely certain that y
our timing is correct.
Next... the nice thing about this and most other well build carbs is that y
ou can always put things back to where they were if you are not satisfied w
ith the change you make. The important thing is to be very careful to know
where you started and how to get back there should you have to. Be very V
ERY careful to document everything. I am tempted to advise you to turn the
adjustment screw out and count the clicks until it reaches the stop, so yo
u know EXACTLY where it is now. However, having not have done this myself.
. and having only read about it... . see what I mean?
It seems that no one on this list has any real first hand experience in mak
ing these adjustments. Me included. Several of us have watched people doi
ng it that seem to understand the concepts. Second hand knowledge to be ex
act.
My YAK-50 will run right up to the red if held in a max performance climb t
o 5000 feet and I consider it to be adjusted perfectly. Push it over and c
limb at Vy, and it will stay at high end of green, just as yours seems to.
It's up to you.
Mark
From: Eric Wobschall
Sent: Sun 10/10/2010 8:25 PM
Subject: Re: Yak-List: Cowl design and CHT
Mark:
I had what I considered to be somewhat high CHT on a VERY LOW TIME first ru
n factory engine. This was with factory settings which I was loathe to touc
h. I'm in Western NY state, so you'd think average settings would cover me.
I have checked and tightened various things, including cylinder and superc
harger case gland nuts. The temps seem to have crept down. Maybe some of it
is break-in, although Jill G. would say break-in is done on a test stand b
efore it sees an airplane. Maybe I've gotten better at managing climb angle
, etc.
Rick Volker has been around this plane and felt there was an issue compared
with the Sukhois he owned. He also feels spinner and cowl play a big part.
as you've read.
I did ring up Vladamir Yastremski (sp?), and he said my temps were well wit
hin acceptable limits, and to worry more about low temps. Dennis S. has sai
d about the same thing in the past. Rick suggested test where I climb-out a
t Vy to 5000 ft. I tried that, and I kept it under 210 C, and then leveled
off at max cruise, after which time it stayed in the high green. So that wa
sn't bad. Now keep in mind this was at 63 degrees ambient at the departure
airport (KBQR 752').
About all of these jets: Richard Goode says they all need adjusting, and I
think it was Sergei Prolegiev who suggested that I get it out of my head th
at it left the factory perfectly adjusted. I do have a slight hesitation wh
en I feed power back in on final, but it's not scary. I have all of the dif
ferent jets, if only I knew what I was doing. I was hoping one or two clock
wise clicks on the cruise mixture adjustment would enrichen the mixture eno
ugh to make my plane and I happy. I do have great fuel economy, so maybe I'
m lean.
Here's my gage and the Yak-UK translated DOSAAF manual I usually go by. Rem
arks, anyone? -Eric
On Oct 10, 2010, at 7:32 PM, Bitterlich, Mark G CIV Det Cherry Point, MALS-
14 64E wrote:
ALS-14 64E" <mark.bitterlich@navy.mil>
No, I am talking about the main mixture jet, which Richard Goode refers to
as the "Compensation Jet". Although yes, I have messed with the one you
are talking about.
Being perfectly clear here Eric, I was just a spectator. I profess no spec
ial knowledge on this darn thing other than:
1. I have seen where adjusting the accelerator pump jet will cure hesitati
on on throttle advancement versus just plugging the darn thing, which was t
he initial cure until smart people figured out you could buy a jet kit and
adjust it accordingly. I am VERY familiar with this kind of thing because
you run into it a lot adjusting a Holley carb where there are many MANY adj
ustments for the amount of fuel you dump in when you move the throttle plat
es.
2. The main jet or "Compensation Jet" has the ability to dramatically cha
nge fuel mixture in the mid to high range of engine RPM.
I would very much love to hear Richard Goode go into more detail on how he
determines how much change to make based on engine indications. He obvious
ly has way more experience than I do. I have seen it done ONCE... but it
worked, in a big way.
I would also like to hear Richard tell me how many clicks on the back of th
e carb equates to one jet size....if that is the case at all.
Mark
________________________________
From: owner-yak-list-server@matronics.com on behalf of Eric Wobschall
Sent: Sun 10/10/2010 4:20 PM
Subject: Re: Yak-List: Cowl design and CHT
Mark, when you say the fuel mixture increase made a big difference, do
you mean the click-stop adjustment on the back of the carburetor?
On Oct 10, 2010, at 3:05 PM, Bitterlich, Mark G CIV Det Cherry Point,
MALS-14 64E wrote:
Point, MALS-14 64E" <mark.bitterlich@navy.mil>
Chris,
I run a YAK-18T spinner on my YAK-50. It is one huge spinner. I
have operated the engine with the spinner off and with the spinner
on, and for the one cylinder in my engine that has a probe stuck in
it, the engine ran somewhat cooler with the spinner attached exactly
as you mention. What the other eight were doing, I have no idea.
That said:
I worked with a gent who put in new higher compression pistons and
new cylinders (on a M-14 engine) and another person who was having
very high oil temperature problems (along with cylinder head temps)
on his M-14PF. In both cases, changing the fuel mixture made a
DRAMATIC change in temperatures. I mean, taking it from borderline
RED down into GREEN. The amount of fuel that is dumped into this
engine makes a dramatic change in temps. Spinners can indeed make
an impact, but not nearly as much as fuel.
Another interesting tidbit. One Sukhoi (that I had time watching)
got equipped with a 9 position cylinder head temperature gage (Hubie
Tolson). I wish he had done an exhaustive study (pun intended) but
he mainly just wanted to make sure that he knew what the hottest jug
was. What cylinder ran highest temps changed dramatically from
running it on the ground, to running it in the air, which is
logical. As I remember, hottest on the ground was #2. However in
the air it moved around to #4 or #5 ... I am not sure of that, it
was awhile ago, but anyway it tends to show that the Russians had a
good idea what they were doing when they stuck the probe where they
did.
Lastly, Richard Goode mentioned that the cylinder head temperature
gages we use are far from being dead nuts calibrated units. I've
found that to be true as well (using a calibrated IR unit by Raytec
and also a Thermal IR video unit). What I found from a sampling of
5 spare probes was fairly consistent readings between probes, but a
big difference between gages. I did not even try to calibrate
mine, but instead just recorded where max temp REALLY was and put a
mark on the gage. We tend to put faith in what a gage is telling
us, but that is really far from true. Comparing cylinder head temps
from one aircraft to another (without first running a calibration
check on the instruments you are using) ends up being very much like
comparing apples to oranges.
As an aside, I have only seen one person mess with the jets on these
engines, and interestingly enough it was done exactly like we did on
the drag strip. Make a change, go up and fly it, come back.. talk
about it... make another change, go up and fly it, etc. I doubt if
there is any real "standard" on how to mess with these things other
than to have some idea what you are trying to cure and what
adjustment you should start with, something I wish I knew far more
about, but don't.
Mark Bitterlich
________________________________
From: owner-yak-list-server@matronics.com on behalf of Chris Wise
Sent: Sat 10/9/2010 7:06 PM
Subject: Re: Yak-List: Cowl design and CHT
G'Day Richard,
Years ago I belonged to the Waikerie Gliding Club and used to fly
the Piper Pawnee 260HP tug.
As I never competed in any big gliding comps I undertook the role as
tugmaster.
Now Waikerie can have temps over 40C on some days as the cyl temps
would get pretty hot if not careful.
We found that running a bigger spinner in the summer would
significantly reduce the cyl head temps as the air was possibly
directed over the cyl heads more so than a smaller spinner.
I would imagine that the USA has similar climated conditions as we
have here in Australia.
When flying the 52 or 18T on these hot summer days, one is always
aware of the cyl temps.
The same applies as did the cyl temps on the Pawnee in the summer.
The Yaks with the big spinners run cooler.
Cheers,
Chris
----- Original Message -----
From: Richard Goode <mailto:richard.goode@russianaeros.com>
To: yak-list@matronics.com
Sent: Saturday, October 09, 2010 11:53 PM
Subject: Re: Yak-List: Cowl design and CHT
The main reason that different M14P engines work at different
temperatures for the same sort of flying is that few owners ever
bother to change the compensating jets,and running with smaller jets
[which means more fuel] will greatly reduce CHT.
The M14P runs very rich most of the time with some of the fuel
going to cool the cylinders.
The jets are easy to change [5 minutes with the cowling off];come
in a range 1.1to 2.1mm.
In fact it is a good idea to change the jet between summer and
winter,to avoid over-cooling in winter.
Richard
Richard Goode Aerobatics
Rhodds Farm
Lyonshall
Hereford
HR5 3LW
United Kingdom
Tel: +44 (0) 1544 340120
Fax: +44 (0) 1544 340129
www.russianaeros.com <http://www.russianaeros.com/>
----- Original Message -----
From: RICHARD VOLKER <mailto:rick@rvairshows.com>
To: yak-list@matronics.com
Sent: Saturday, October 09, 2010 2:50 PM
Subject: Yak-List: Cowl design and CHT
s.com>
I have noticed large differences in the CHT temps of two
Sukhois and three Yak 52's running similar power levels. Sukhois
seem to be able to maintain cool CHT's through any operating
condition and duration, with hovering at full power on a 95 degree
day giving green CHT's. The cowl design on the Sukhoi has a leading
edge that is an airfoil, with an inner cowl shape to speed airflow.
The Yak 52 uses a cowl design that is a shell with the same external
shape and no "flying" surface internally to speed airflow. All three
of the Yak 52's I have flown seem to be limited to climbing Vy at
max cruise. At any rate, they seem significantly hotter at much less
extreme conditions. Cowl vents on the Sukhoi are a louver design.
On the Yak, the cowl venting is a large opening behind the cowl.
When the Sukhoi Design Bureau added horsepower with the M9R engine,
they added a larger oil cooler and louvers on the side of the cowl
that looked more like rear facing opening of a Yak 52. T!
he!
se Russians must talk to each other!
Has anyone seen the BEAR 360 that has been marketed by Ski
p
Holm? Skip has incorporated many of his Reno race speed tricks on
this M14P powered aircraft. The actual airframe design was penned
by Sergei Yakovlev. Skip Holm has put a giant spinner on his Bear
360. He has also devised an added aerodynamic device placed behind
the spinner to further reduce drag (unknown effect on CHT). Exhausts
are flush and aim back into the airflow. The decreased back
pressure has increased power. The exhaust pressure in the backwards
direction contribute to airspeed. I am told that six inches of
protruding exhausts give several knots of speed penalty. Much has
been said about CO buildup and exhaust design. I hope they have done
their homework in that respect.
My question is this: Since more Yak 52 owners are playing
in
extreme corners of the operating envelope with a perceived need to
maintain lower cylinder head temps, should owners develop cowl mods
to improve cooling? Has anyone attempted to build airfoil shapes
internal to the existing cowl? Behind the spinner ? I noticed a CHT
reduction of an average of 20 degrees going from the Russian V530
two blade prop without spinner to the three blade MT with large
spinner. Surely there are other mods that could help manage CHT
further. Am I alone in this thought? My contention is that it would
be beneficial to be able to climb at any airspeed above the stall at
full power as long as you wish, ala Sukhoi, without getting into
yellow CHT's.
Rick Volker
p; Navigator Photoshare, and href="http://www.matroni
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Eric D. Wobschall
Buffalo Skyline
Buffalo-Lancaster Airport (KBQR):
4343 Walden Avenue
Lancaster, NY 14086
Office:
2120 Maple Road
Williamsville, NY 14221-1922
716.208.5460
Message 7
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| Subject: | Re: Cowl design and CHT |
M14 Stroke:
#4 - 130.00 mm
#3 and #5 130.15 mm
#2 and #6 130.23 mm
#8 and #9 130.39 mm
#1 and #7 131.25 mm
Largest difference #4 to #1 or #7 = 1.25 mm
Dennis
----- Original Message -----
From: A. Dennis Savarese
To: yak-list@matronics.com
Sent: Monday, October 11, 2010 10:25 AM
Subject: Re: Yak-List: Re: Cowl design and CHT
<dsavarese0812@bellsouth.net>
Different stroke lengths-yes. SEVERAL mm - no. Check the specs in the
M14 maint manual. Dennis
Sent from my iPhone
On Oct 10, 2010, at 8:38 PM, "Vic" <vicmolnar@aol.com> wrote:
>
> Hello,
>
> another thing to keep in mind : In a radial engine you have
different stroke for each piston, in fact several millimeters difference
in the M14. So you have different compression ratios as well. This will
have some effect on power and temperature for each cylinder. But then,
this should concern cylinders with some of the longest strokes to run
hotter than the rest. Maybe this fact gets clouded by some other effects
still unreflected.
>
> Vic
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=315298#315298
>
>
>
>
>
>
>
>
>
>
Message 8
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| Subject: | Re: Cowl design and CHT |
Thanks, Mark. Plugging it into the formula.
On Oct 11, 2010, at 2:26 PM, Bitterlich, Mark G CIV Det Cherry Point,
MALS-14 64E wrote:
> I really do not feel qualified to advise you on any of this. If you
> are asking for my OPINION... well... ok.
>
> The slight hesitation when adding power on final can probably be
> cured by changing the size of the Acceleration Pump jet. However, I
> would not do this if you plan on messing with other adjustments.
> I'd do it last. However, I WOULD mess with this one. It's easy and
> the change will be felt immediately when you go flying and you are
> not messing with fuel ratios. Just fuel delivered when the throttle
> is moved.
>
> I trust Vladimir Yastremski and Dennis and realize fully that both
> of them have more knowledge and experience on this engine than I
> probably ever will have.
>
> But if you want to go on .......
>
> Before even thinking of adjusting your carb, make absolutely certain
> that your timing is correct.
>
> Next... the nice thing about this and most other well build carbs is
> that you can always put things back to where they were if you are
> not satisfied with the change you make. The important thing is to
> be very careful to know where you started and how to get back there
> should you have to. Be very VERY careful to document everything. I
> am tempted to advise you to turn the adjustment screw out and count
> the clicks until it reaches the stop, so you know EXACTLY where it
> is now. However, having not have done this myself.. and having only
> read about it... . see what I mean?
>
> It seems that no one on this list has any real first hand experience
> in making these adjustments. Me included. Several of us have
> watched people doing it that seem to understand the concepts.
> Second hand knowledge to be exact.
>
> My YAK-50 will run right up to the red if held in a max performance
> climb to 5000 feet and I consider it to be adjusted perfectly. Push
> it over and climb at Vy, and it will stay at high end of green, just
> as yours seems to.
>
> It's up to you.
>
> Mark
>
>
> From: Eric Wobschall
> Sent: Sun 10/10/2010 8:25 PM
> To: yak-list@matronics.com
> Subject: Re: Yak-List: Cowl design and CHT
>
> Mark:
>
> I had what I considered to be somewhat high CHT on a VERY LOW TIME
> first run factory engine. This was with factory settings which I was
> loathe to touch. I'm in Western NY state, so you'd think average
> settings would cover me. I have checked and tightened various
> things, including cylinder and supercharger case gland nuts. The
> temps seem to have crept down. Maybe some of it is break-in,
> although Jill G. would say break-in is done on a test stand before
> it sees an airplane. Maybe I've gotten better at managing climb
> angle, etc.
>
> Rick Volker has been around this plane and felt there was an issue
> compared with the Sukhois he owned. He also feels spinner and cowl
> play a big part. as you've read.
>
> I did ring up Vladamir Yastremski (sp?), and he said my temps were
> well within acceptable limits, and to worry more about low temps.
> Dennis S. has said about the same thing in the past. Rick suggested
> test where I climb-out at Vy to 5000 ft. I tried that, and I kept it
> under 210 C, and then leveled off at max cruise, after which time it
> stayed in the high green. So that wasn't bad. Now keep in mind this
> was at 63 degrees ambient at the departure airport (KBQR 752').
>
> About all of these jets: Richard Goode says they all need adjusting,
> and I think it was Sergei Prolegiev who suggested that I get it out
> of my head that it left the factory perfectly adjusted. I do have a
> slight hesitation when I feed power back in on final, but it's not
> scary. I have all of the different jets, if only I knew what I was
> doing. I was hoping one or two clockwise clicks on the cruise
> mixture adjustment would enrichen the mixture enough to make my
> plane and I happy. I do have great fuel economy, so maybe I'm lean.
>
> Here's my gage and the Yak-UK translated DOSAAF manual I usually go
> by. Remarks, anyone? -Eric
>
>
> On Oct 10, 2010, at 7:32 PM, Bitterlich, Mark G CIV Det Cherry
> Point, MALS-14 64E wrote:
>
>> Point, MALS-14 64E" <mark.bitterlich@navy.mil>
>>
>> No, I am talking about the main mixture jet, which Richard Goode
>> refers to as the "Compensation Jet". Although yes, I have messed
>> with the one you are talking about.
>>
>> Being perfectly clear here Eric, I was just a spectator. I profess
>> no special knowledge on this darn thing other than:
>>
>> 1. I have seen where adjusting the accelerator pump jet will cure
>> hesitation on throttle advancement versus just plugging the darn
>> thing, which was the initial cure until smart people figured out
>> you could buy a jet kit and adjust it accordingly. I am VERY
>> familiar with this kind of thing because you run into it a lot
>> adjusting a Holley carb where there are many MANY adjustments for
>> the amount of fuel you dump in when you move the throttle plates.
>>
>> 2. The main jet or "Compensation Jet" has the ability to
>> dramatically change fuel mixture in the mid to high range of engine
>> RPM.
>>
>> I would very much love to hear Richard Goode go into more detail on
>> how he determines how much change to make based on engine
>> indications. He obviously has way more experience than I do. I
>> have seen it done ONCE... but it worked, in a big way.
>>
>> I would also like to hear Richard tell me how many clicks on the
>> back of the carb equates to one jet size....if that is the case at
>> all.
>>
>> Mark
>>
>>
>> ________________________________
>>
>> From: owner-yak-list-server@matronics.com on behalf of Eric Wobschall
>> Sent: Sun 10/10/2010 4:20 PM
>> To: yak-list@matronics.com
>> Subject: Re: Yak-List: Cowl design and CHT
>>
>>
>>
>> >
>>
>> Mark, when you say the fuel mixture increase made a big difference,
>> do
>> you mean the click-stop adjustment on the back of the carburetor?
>>
>>
>> On Oct 10, 2010, at 3:05 PM, Bitterlich, Mark G CIV Det Cherry Point,
>> MALS-14 64E wrote:
>>
>>> Point, MALS-14 64E" <mark.bitterlich@navy.mil>
>>>
>>> Chris,
>>>
>>> I run a YAK-18T spinner on my YAK-50. It is one huge spinner. I
>>> have operated the engine with the spinner off and with the spinner
>>> on, and for the one cylinder in my engine that has a probe stuck in
>>> it, the engine ran somewhat cooler with the spinner attached exactly
>>> as you mention. What the other eight were doing, I have no idea.
>>>
>>> That said:
>>>
>>> I worked with a gent who put in new higher compression pistons and
>>> new cylinders (on a M-14 engine) and another person who was having
>>> very high oil temperature problems (along with cylinder head temps)
>>> on his M-14PF. In both cases, changing the fuel mixture made a
>>> DRAMATIC change in temperatures. I mean, taking it from borderline
>>> RED down into GREEN. The amount of fuel that is dumped into this
>>> engine makes a dramatic change in temps. Spinners can indeed make
>>> an impact, but not nearly as much as fuel.
>>>
>>> Another interesting tidbit. One Sukhoi (that I had time watching)
>>> got equipped with a 9 position cylinder head temperature gage (Hubie
>>> Tolson). I wish he had done an exhaustive study (pun intended) but
>>> he mainly just wanted to make sure that he knew what the hottest jug
>>> was. What cylinder ran highest temps changed dramatically from
>>> running it on the ground, to running it in the air, which is
>>> logical. As I remember, hottest on the ground was #2. However in
>>> the air it moved around to #4 or #5 ... I am not sure of that, it
>>> was awhile ago, but anyway it tends to show that the Russians had a
>>> good idea what they were doing when they stuck the probe where they
>>> did.
>>>
>>> Lastly, Richard Goode mentioned that the cylinder head temperature
>>> gages we use are far from being dead nuts calibrated units. I've
>>> found that to be true as well (using a calibrated IR unit by Raytec
>>> and also a Thermal IR video unit). What I found from a sampling of
>>> 5 spare probes was fairly consistent readings between probes, but a
>>> big difference between gages. I did not even try to calibrate
>>> mine, but instead just recorded where max temp REALLY was and put a
>>> mark on the gage. We tend to put faith in what a gage is telling
>>> us, but that is really far from true. Comparing cylinder head temps
>>> from one aircraft to another (without first running a calibration
>>> check on the instruments you are using) ends up being very much like
>>> comparing apples to oranges.
>>>
>>> As an aside, I have only seen one person mess with the jets on these
>>> engines, and interestingly enough it was done exactly like we did on
>>> the drag strip. Make a change, go up and fly it, come back.. talk
>>> about it... make another change, go up and fly it, etc. I doubt if
>>> there is any real "standard" on how to mess with these things other
>>> than to have some idea what you are trying to cure and what
>>> adjustment you should start with, something I wish I knew far more
>>> about, but don't.
>>>
>>> Mark Bitterlich
>>>
>>>
>>>
>>> ________________________________
>>>
>>> From: owner-yak-list-server@matronics.com on behalf of Chris Wise
>>> Sent: Sat 10/9/2010 7:06 PM
>>> To: yak-list@matronics.com
>>> Subject: Re: Yak-List: Cowl design and CHT
>>>
>>>
>>> G'Day Richard,
>>>
>>> Years ago I belonged to the Waikerie Gliding Club and used to fly
>>> the Piper Pawnee 260HP tug.
>>> As I never competed in any big gliding comps I undertook the role as
>>> tugmaster.
>>> Now Waikerie can have temps over 40C on some days as the cyl temps
>>> would get pretty hot if not careful.
>>> We found that running a bigger spinner in the summer would
>>> significantly reduce the cyl head temps as the air was possibly
>>> directed over the cyl heads more so than a smaller spinner.
>>>
>>> I would imagine that the USA has similar climated conditions as we
>>> have here in Australia.
>>> When flying the 52 or 18T on these hot summer days, one is always
>>> aware of the cyl temps.
>>> The same applies as did the cyl temps on the Pawnee in the summer.
>>> The Yaks with the big spinners run cooler.
>>>
>>> Cheers,
>>> Chris
>>>
>>>
>>>
>>>
>>> ----- Original Message -----
>>> From: Richard Goode <mailto:richard.goode@russianaeros.com>
>>> To: yak-list@matronics.com
>>> Sent: Saturday, October 09, 2010 11:53 PM
>>> Subject: Re: Yak-List: Cowl design and CHT
>>>
>>> The main reason that different M14P engines work at different
>>> temperatures for the same sort of flying is that few owners ever
>>> bother to change the compensating jets,and running with smaller jets
>>> [which means more fuel] will greatly reduce CHT.
>>> The M14P runs very rich most of the time with some of the fuel
>>> going to cool the cylinders.
>>> The jets are easy to change [5 minutes with the cowling
>>> off];come
>>> in a range 1.1to 2.1mm.
>>> In fact it is a good idea to change the jet between summer and
>>> winter,to avoid over-cooling in winter.
>>> Richard
>>>
>>> Richard Goode Aerobatics
>>> Rhodds Farm
>>> Lyonshall
>>> Hereford
>>> HR5 3LW
>>> United Kingdom
>>>
>>> Tel: +44 (0) 1544 340120
>>> Fax: +44 (0) 1544 340129
>>> www.russianaeros.com <http://www.russianaeros.com/>
>>>
>>>
>>> ----- Original Message -----
>>> From: RICHARD VOLKER <mailto:rick@rvairshows.com>
>>> To: yak-list@matronics.com
>>> Sent: Saturday, October 09, 2010 2:50 PM
>>> Subject: Yak-List: Cowl design and CHT
>>>
>>> >
>>>
>>>
>>> I have noticed large differences in the CHT temps
>>> of two
>>> Sukhois and three Yak 52's running similar power levels. Sukhois
>>> seem to be able to maintain cool CHT's through any operating
>>> condition and duration, with hovering at full power on a 95 degree
>>> day giving green CHT's. The cowl design on the Sukhoi has a leading
>>> edge that is an airfoil, with an inner cowl shape to speed airflow.
>>> The Yak 52 uses a cowl design that is a shell with the same external
>>> shape and no "flying" surface internally to speed airflow. All three
>>> of the Yak 52's I have flown seem to be limited to climbing Vy at
>>> max cruise. At any rate, they seem significantly hotter at much less
>>> extreme conditions. Cowl vents on the Sukhoi are a louver design.
>>> On the Yak, the cowl venting is a large opening behind the cowl.
>>> When the Sukhoi Design Bureau added horsepower with the M9R engine,
>>> they added a larger oil cooler and louvers on the side of the cowl
>>> that looked more like rear facing opening of a Yak 52. T!
>>> he!
>>> se Russians must talk to each other!
>>>
>>> Has anyone seen the BEAR 360 that has been
>>> marketed by Skip
>>> Holm? Skip has incorporated many of his Reno race speed tricks on
>>> this M14P powered aircraft. The actual airframe design was penned
>>> by Sergei Yakovlev. Skip Holm has put a giant spinner on his Bear
>>> 360. He has also devised an added aerodynamic device placed behind
>>> the spinner to further reduce drag (unknown effect on CHT). Exhausts
>>> are flush and aim back into the airflow. The decreased back
>>> pressure has increased power. The exhaust pressure in the backwards
>>> direction contribute to airspeed. I am told that six inches of
>>> protruding exhausts give several knots of speed penalty. Much has
>>> been said about CO buildup and exhaust design. I hope they have done
>>> their homework in that respect.
>>>
>>> My question is this: Since more Yak 52 owners
>>> are playing in
>>> extreme corners of the operating envelope with a perceived need to
>>> maintain lower cylinder head temps, should owners develop cowl mods
>>> to improve cooling? Has anyone attempted to build airfoil shapes
>>> internal to the existing cowl? Behind the spinner ? I noticed a CHT
>>> reduction of an average of 20 degrees going from the Russian V530
>>> two blade prop without spinner to the three blade MT with large
>>> spinner. Surely there are other mods that could help manage CHT
>>> further. Am I alone in this thought? My contention is that it would
>>> be beneficial to be able to climb at any airspeed above the stall at
>>> full power as long as you wish, ala Sukhoi, without getting into
>>> yellow CHT's.
>>>
>>> Rick Volker
>>> p; Navigator Photoshare, and href="http://www.matronics.com/Navigator?Yak-List
>>> ">http://www.matronics======================== <http://www.matronics========================/
>>> > <; via the Web
>>> href="http://forums.matronics.com <http://forums.matronics.com/> ">http://forums.matronics.com
>>> <http://forums.matronics.com/>
>>> _p; generous bsp; href="http://www.matronics.com/contribution
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>> http://www.matronics.========================http://www.matronics.com/co================
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>>
>
>
> Eric D. Wobschall
> Buffalo Skyline
> Buffalo-Lancaster Airport (KBQR):
> 4343 Walden Avenue
> Lancaster, NY 14086
> Office:
> 2120 Maple Road
> Williamsville, NY 14221-1922
> 716.208.5460
>
>
Message 9
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| Subject: | Things that make you go Hmmm |
Whilst celebrating my now drip-free engine (still weeps in spots though), I sought
to double check my valve lash after a couple of flights since pulling everything
out and reinstalling same.
Of course I caught some screw-ups...adjustment nuts not torqued down and such but
what startled me was to spot 2 needle bearings laying next to the valve spring
on #7, kinda under it.
Sooo, I pull off the offending rocker arm, all slathered up in MMO-laced oil and
it slips from my fingers. No big deal, I positioned a dump can underneath. carefully
counting out each bearing, I came up with 58, not the 56 spec'd in the
part catalog; that's counting the 2 I found. After carefully placement, not
once but twice; hate when that happens, I realized that those two bearings had
been there for the last 653 hours since OH, since I never pulled off the rocker
arms on this engine.
BTW, I made a placement tool from forming SS safety wire since it is non-magnetic
to push the bearings into place. Doing this involves grinding the end of the
wire flat. Also used a 10mm bolt shaft to hold the assembly together for work
and placement.
Not something I want to do everyday. Kinda like swapping out the air compressor,
timing the air distributor, or getting a root canal.
Craig Payne
Message 10
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N13472(at)aol.com wrote:
> Any one have a lower right gear door they want to part with?????
>
> Tom Elliott
> CJ-6A NX63727
> 702-595-2680
Hello!I'm Sarah we specialize in CJ6 parts in China.please contact with us off
list.This is my e-mail address: lcdzkj@live.cn
--------
Sarah's E-mail:lcdzkj@live.cn
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315405#315405
Message 11
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| Subject: | Re: Worldwide Warbirds seeking inventory |
Hello Barry,
We also sell Nanchang CJ6 plane and parts in China.Are you interested in it?If
yes,please feel free to contact with us.Thanks!Sarah
--------
Sarah's E-mail:lcdzkj@live.cn
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=315406#315406
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