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Throttle setting at higher cruising altitudes
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mark.bitterlich(at)navy.m
Guest

Posted: Thu Nov 29, 2007 8:50 pm Post subject: Throttle setting at higher cruising altitudes

 	  Quote: 	
		  I don't have the M14P manual to refer to but Steve has just posted the

Cruise 1 setting of 64% and 735 mm/hg. This is a recommended limit.
	




Walt, I am sorry... No it is not a recommended limit.  It is performance

setting where you should get documented results.  It is like a Vx or Vy

speed.  You climb at those speeds at a given weight, and you should

obtain a known end.  These are not limits.  Because the manual documents

a Cruise 1 setting and a Cruise 2 setting, that these are the only two

places that you are allowed to cruise?  No Sir.  My manual clearly

states that full throttle is available at ANY RPM SETTING.  When I get

home tonight, I will pull it out and find it and quote it.  



 	  Quote: 	
		  Granted that as altitude increases the throttle must be opened to

maintain the desired MP. Since these engines have a low blower ratio
	


compared to an "altitude" engine the full throttle altitude will be

reached very quickly. 

In fact it is actually sea level but only with the power settings given

in the manual.

I absolutely agree with Steve's first post to use max. manifold pressure

for a given RPM. He has revised it a bit to a given power setting rather

than RPM but I think he means the same. The "power setting" is a

combination of RPM and MP.

I'm sure you would agree that at sea level a power setting of full

throttle and 1450 (50%)RPM could be fairly described as over boosted.



I understand that we both understand how manifold pressure works and are

not disagreeing over nonsense.  But actually no Walt I would not

consider 55 or 60% RPM (mine simply will not go that low at full

throttle) with full throttle to be "over-boosted".  I honestly do not

usually run it all the way down to 60% with full throttle, but I do it

regularly at 70%.  I have run for an hour at 1000 feet with 70% RPM and

full throttle.  Sounds good, runs good.  



Consider if you will that some of the big blowers on some of the heavy

iron birds out there are/were capable of well over 50 inches of "boost".

Some of them would go so high that water injection was used.  Now we

have an engine turning 2950 RPM developing a few thousand horsepower in

this condition.  This was not considered "over-boosted".  



Then we have an engine which has a max horsepower of 360 that develops

around 34 or so inches of manifold pressure at sea level (plus or minus

2 inches or so), and we apply that to an engine turning say 1500 or so

RPM, and this is suddenly over-boosted simply because it used the same

manifold pressure at a higher RPM?  



Do I feel that there are no limits?  Well, certainly there are with some

motors, but apparently not with the M-14P because the books that I have

read specifically says otherwise.  



This is a much better discussion than most lately by the way... It has

serious bearing on how we all fly.  



Mark



---

viperdoc(at)mindspring.co
Guest

Posted: Thu Nov 29, 2007 9:06 pm Post subject: Throttle setting at higher cruising altitudes

I am looking at "exploitation parameters with respect to the Running

Conditions" as stated in the translated "IAK 52 School and Training Aircraft

Flight Manual".

Walt is absolutely correct for the Cruise 1 that Mozam referred to is for

sea level operating parameters as best I can tell. Remember as you climb in

altitude the atmospheric pressure decreases so to maintain the same manifold

pressure and approximate HP, you have to open the advance (the inboard

manifold pressure lever). Not to be too simple here.



Running Condition.....Engine Speed (%)....Pressure Of Air (at) engine intake

(mmHg col.).....Fuel Spec. Consumption(g/hP.hr)

Cruise 1................64 +/-1..........................735 +/-

15..........................215-235 

Cruise 2................59 +/-1..........................670 +/-

15..........................210-230

Nominal 1...............70 +/-1..........................75-15

(over)........................265-300

Nominal 2...............82 +/-1..........................95-15

(over)........................280-310

T-O      ...............99 +/-1..........................125-15

(over).......................285-315



Here is a table that gives the atmospheric pressure at various altitudes.

The altitude is given in feet and the pressure is in inches of mercury.



Altitude           Pressure           Altitude          Pressure



    0,000                 29.92              20,000               13.75

    1,000                 28.86              25,000               11.10

    2,000                 27.82              30,000               8.886



    3,000                 26.82              35.000               7.041

    4,000                 25.84              40,000               5.538

    5,000                 24.89              45,000               4.355



  10,000                 20.58              50,000               3.425

  15,000                 16.88              60,000               2.118

  18,000 *               14.94            100,000               0.329



* This is almost exactly one-half the sea-level value.

      To convert in/Hg to psi, multiply by 0.491.

  (at) 18,000 ft = 1/2 atm, (at) 35,000 ft = 1/5 atm (atmosphere)



Pressure Equivalents:



1 Atmosphere (as a unit of pressure) = 14.7 psi = 34 ft water column = 76

cm/Hg 

     = 29.92 in/Hg = 1.013 bar = 1,013 mbar

1 bar = 1,000 mbar = 14.5 psi = 29.53 in/Hg = 0.9869 atm

1 psi = 27.68 inches water column = 2.036 in/Hg = 6.859 kPa

1 kPa = 1,000 Pascals = 0.1458 psi



Brain and Steve eloquently said it in their earlier post. Open the advance

to maintain airflow and hp at a given altitude since the barometric pressure

is decreasing as altitude increases.

--

viperdoc(at)mindspring.co
Guest

Posted: Thu Nov 29, 2007 9:12 pm Post subject: Throttle setting at higher cruising altitudes

Copy. Kinda thought that was what you meant.



Doc



--

brian-1927(at)lloyd.com
Guest

Posted: Thu Nov 29, 2007 9:44 pm Post subject: Throttle setting at higher cruising altitudes

On Nov 29, 2007, at 6:44 PM, N13472(at)aol.com wrote:



 	  Quote: 	
		   In a message dated 11/29/2007 5:34:25 P.M. Pacific Standard Time,  

 wlannon(at)persona.ca writes:

 absolutely agree with Steve's first post to use max. manifold  

 pressure for

 a given RPM. He has revised it a bit to a given power setting  

 rather than

 RPM but I think he means the same. The "power setting" is a  

 combination of

 RPM and MP.

 I'm sure you would agree that at sea level a power setting of full  

 throttle

 and 1450 (50%)RPM could be fairly described as over boosted.



 Cheers;

 Walt

 Walt, does not the Cj-6A manual say that Max power is 2350 rpm M/P  

 ambient + 85 mm ?


	


Yes.



It also says that you may maintain that for 5 minutes. If you want to  

run for an hour it is 2250 and ambient + 80mm, after which you must  

give the engine a five-minute rest. If you want to run continuously  

it is 710mm and 2250 RPM.



FWIW I used to run my Huosai at 1850 RPM and full-throttle from sea- 

level to whatever.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

brian-1927(at)lloyd.com
Guest

Posted: Thu Nov 29, 2007 9:46 pm Post subject: Throttle setting at higher cruising altitudes

On Nov 29, 2007, at 7:55 PM, Mark Davis wrote:



 	  Quote: 	
		   



 Doc,

    I use 65% to take the free ride of the tailwind.  70% to reduce  

 the time the headwind has to work on me.  Navy technique we used.   

 In significant headwinds we always ran at near military power  

 settings.  Max endurance AOA with a strong tailwind when trying to  

 stretch range.


	


Yes. Max endurance AoA is best L/D. The AoA indicator makes it easy  

to find.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

dsavarese(at)elmore.rr.co
Guest

Posted: Fri Nov 30, 2007 5:33 am Post subject: Throttle setting at higher cruising altitudes

This chart is also available on my web site, www.yak-52.com, WITH FUEL 

CONSUMPTION at the various power settings.  Not in grams/horsepower/hour, 

but in Gallons and Liters per hour.

Dennis



---

Mozam

Joined: 24 Nov 2006
Posts: 85

Posted: Fri Nov 30, 2007 12:45 pm Post subject: Re: Throttle setting at higher cruising altitudes

 	  Mozam wrote: 	
		  

I will experiment further and report my findings.  Any excuse to go fly is a good one!!    

	




Well, here's what I learned today.  I *hope* the Excel sheet I attached comes thru.



Some of this data was very surprising to me.  However, I think it does prove there is no "full throttle enrichment" on the M14P.



The highest MAP shown for each condition was with the throttle on the front stop.



The Sea Level data was flown at wave top height over Chesapeake Bay.



I had been fiddling with my prop governor and could only get 2800 RPM out of it.



I'm very interested in your opinions of cruise power settings based on this data.



-Steve

Yak Fuel Flow Analysis.xls

Description:

Download

Filename:

Yak Fuel Flow Analysis.xls

Filesize:

20 KB

Downloaded:

449 Time(s)

LawnDart

Joined: 05 Jun 2006
Posts: 64

Posted: Fri Nov 30, 2007 1:28 pm Post subject: Re: Throttle setting at higher cruising altitudes

All of this throttle "to the stops" talk has me wondering...  My throttle stops are adjustable.  I am not sure we can say "top the stops" means the same on all M14P installations.

wlannon(at)persona.ca
Guest

Posted: Fri Nov 30, 2007 4:23 pm Post subject: Throttle setting at higher cruising altitudes

Mark;



I guess I am not explaining this properly. There are boost limits with all 

engines, including the M14. They are a function of propellor loading.

I did NOT say that the given cruise settings were the only ones allowed for 

cruise. If you wish to burn the gas you may cruise at T/O for 5 mins. or at 

any setting between T/O and Cruise 1 ( or even lower if you wish) but you 

should ensure that you balance the RPM and MP accordingly.



 I doubt you would even consider low altitude cruise at full throttle with 

the prop control at minimum RPM or attempt a take-off in the same condition 

both of  which you have stated are perfectly acceptable for the M14 and I 

quote "-------there are no " boost limits" to this engine at ANY RPM"



I refer you to the M14P Maintenance Manual, 072.00.00, Pg. 14, Para. 2.2.2, 

bottom of page which states  "----- do not set the airscrew to higher pitch 

before decreasing boost, otherwise the crank mechanism of the engine may be 

heavily overloaded. To increase engine rating, first  increase its speed to 

the desired one (relieve the airscrew) and then increase boosting." and rest 

my case.



Walt



---

viperdoc(at)mindspring.co
Guest

Posted: Fri Nov 30, 2007 7:27 pm Post subject: Throttle setting at higher cruising altitudes

Mozam,

Appears that "over square" is not the way to make gas at any altitude from

your data. It appears that pulling the "advance" back to even or slightly

under square.

Doc



--

Mozam

Joined: 24 Nov 2006
Posts: 85

Posted: Sat Dec 01, 2007 9:15 am Post subject: Re: Throttle setting at higher cruising altitudes

 	  viperdoc(at)mindspring.co wrote: 	
		  Mozam,

Appears that "over square" is not the way to make gas at any altitude from

your data. It appears that pulling the "advance" back to even or slightly

under square.

Doc



-- 	




Doc,



I read this data a little differently (at least at high altitude).  



Note the absolute best fuel economy I saw (12.1 mpg) was at 10,000' with the prop pulled back to 60% and the throttle at the front stop.



And at 10,000' the best fuel economy/speed combination at 64% is with the throttle at the front stop.



Finally at 10,000', if you want to go fast, set the prop at 70% and throttle fire-walled to get 162 true mph at 10.6 mpg.



Also noteworthy, IMHO, is that at 5,000' the best fuel economy cruise settings are just about exactly where the aircraft manual lists "cruise 1 and cruise 2" conditions (1860 rpm/64% and 28"/711 mm, and at 1730 rpm/60% and 27"/686 mm).  Perhaps we need to give the manufacturer some credit here?



I wish I had completed the data for sea level, but I got tired of dodging ducks and gulls!!.  I'll post it when I get it.



Note: there is a typo on the spreadsheet.  The 10,000', 2400 rpm, 24" MAP fuel flow should be 16.6 and the MPG should be 9.64.



-Steve

viperdoc(at)mindspring.co
Guest

Posted: Sat Dec 01, 2007 9:51 pm Post subject: Throttle setting at higher cruising altitudes

Mozam,

I obviously read the data wrong. If I downloaded your spread sheet. Will

have to wait until I get a fuel flow monitor to see how is compares to the

50. 

Thanks for setting me straight, 



Doc



--

mark.bitterlich(at)navy.m
Guest

Posted: Mon Dec 03, 2007 2:32 pm Post subject: Throttle setting at higher cruising altitudes

Walt,  



I have no argument about it being highly inadvisable to have full RPM

and throttle set, and then yank the RPM to minimum while leaving the

throttle wide open.  I also have no disagreement that when increasing

RPM, the prop control should be increased before the throttle.  



The fact is, I don't believe any of this is what was being discussed.

If it was, then I am sorry, because I misunderstood what you were

saying.  What I thought you were saying dealt with the inadvisability of

running manifold settings "too high" as compared to a fixed RPM.  What I

said was that it is my belief is that you can set the throttle to full,

even at sea level, with the engine RPM reduced.  For example, you said:

"There are varying RPM/manifold pressure limits for every engine with a

variable pitch propellor.  Probably the easiest (but not recommended)

way to find the first one is to attempt a take-off with the prop control

at low RPM."



For an example of what *I* was talking about:  See Yak 50 Operating

Manual:  Pre-takeoff Engine Performance Test:  "Decrease engine RPM to

70% with propeller control.  Increase throttle to wide open.  Check

engine instruments."  By the way, this is a ground test.  As you can see

from this test, the operating manual is telling you to run the engine

with the throttle at maximum manifold pressure with the engine RPM

reduced to 70% with the prop control.  Further, it is very difficult to

get any stock M-14 with a standard 2 blade to do much less than 70% RPM

when the throttle is fully wide open.  65% maybe, but 59% is next to

impossible with the models I have flown. 



I have no desire to take-off with the RPM reduced to 70%.  However, I

often cruise around at sea-level with RPM set anywhere from 75%-85% and

the throttle set WIDE OPEN, and I do not believe I am operating the

engine in such a way as to damage it.  



Be that as it may, I support you operating your engine anyway you see

fit.  



Mark

 



--

jan.mevis(at)informavia.b
Guest

Posted: Mon Dec 03, 2007 11:36 pm Post subject: Throttle setting at higher cruising altitudes

Mark and Walt,



Now I am puzzled about the proper procedures. I would be obliged if you and

others could correct me about the following procedure (my fellow Yak 52

owners do this more or less in the same way):



1. before startup, we eventually heat the oil with a small electrical

"spiral" device (the things used for heating water in a cup). I personally

turn the prop AT LEAST 25 blades; prime left and right 4 times, pull the

prop 5 or 6 blades; prime again the cylinders 2  to 3 times; the engine

usually fires after I saw moving three to four blades (three-bladed prop).



2. at startup, the prop control is fully fine (governor control lever

completely to the front), 



3. when engine started, I let it run at 42 % (with throttle control very

slowly up until 40 or 42 % is reached, prop all this time full fine) until

the proper temperatures are reached.



4. then I taxi to the holding point, prop still full fine, but reducing the

throttle a lot less than 40 %,just above idle, otherwise my Yak 50 rolls too

fast



5. run-up tests: check first if the engine still has the proper temperatures

(oil above 40 degrees, CHT at 150 degrees); then throttle up to 70 % for the

magneto checks, and then 3 times governor control by pulling back and forth

the prop lever; not too fast, but firmly (with the Extra 300 that I may fly,

the owner asked me to do this prop checks very quickly because they only

have to take away the air bubbles in the governor; he got this advise when

he bought his Extra 300 new from the factory; I suppose this makes sense for

his specific governor mechanism).



6. at take-off, my prop control is full fine, and I SLOWLY advance the

throttle to full power, so having the Yak 50 roll smoothly. I don't push the

stick forward, but keep it in the middle, slightly back, so that the plane

gets airborne from the three wheels at the same time. Then I lower the nose,

gear up, let speed go up; when at 500 feet, I reduce the RPM to 82 % but

leave the throttle full open. In cruise flight, I always have the

prop/throttle settings slightly "oversquare" i.e. 70 % prop, 75 throttle or

60/65.



7. in final approach, I have the prop control at 70 % and use the throttle

(and nose position and trim) to establish the correct speed (145 to 150

km/h, is what I need for a good three-pointer). I aim for the numbers, and

just above the numbers, I have the throttle completely idle.



8. for run-down, I advance the throttle a bit, I put the prop governor again

at fully fine, and the throttle to 65 %, have it scavenge the oil for 25

seconds, then I pull back the throttle to 43 %, shut down the magneto's and

immediately I advance the throttle fully. (in my experience this helps to

avoid big flames at the exhaust pipes; I've seen this on several engines).



Jan Mevis

YK50 RA2005K

wlannon(at)persona.ca
Guest

Posted: Tue Dec 04, 2007 10:36 am Post subject: Throttle setting at higher cruising altitudes

Jan;



Your procedure sounds just fine to me. It is in accordance with the 

Maintenance Manual procedures as I recall them.

I would suggest though that on final approach when closing the throttle it 

would be wise to go to fine pitch..

This is standard procedure to ensure full power is immediately available for 

an emergency go around. Probably quite unnecessary in a Yak 50 with a power 

to weight ratio around 5 lb/HP but

good to have standard procedures ingrained for when you are flying something 

else.



Cheers;

Walt

---

viperdoc(at)mindspring.co
Guest

Posted: Tue Dec 04, 2007 11:33 am Post subject: Throttle setting at higher cruising altitudes

Walt,

The YAK50 manual calls for 70% and 400 mmHg on final. I personally tend to descend with the pitch set at 80%. Not necessarily for go around but for a "speed brake"! She will jump from 150 Kilo/sec to 170 kps in a heart beat if you lower the alpha by letting the nose drop during final turn. If I have to do a go round, 80% and 850 mmHG is more than enough power with the risk of torque rolling her a 100% and 850 mmHG. She will lift the left main off the ground if you push it suddenly for sure.

For the start I pull 14 blades with the intake open. If there is sluggish flow of oil out of the intake drain, I will prime with 4-6 strokes looking for fuel to lfow out of the intake. I then pull another 8-12 and wait until the oil stops draining out of the intake. After that, I close the intake, give it a couple of strokes of prime, and pull 4 blades stopping on the compression. Start is generally one blade tic to fire off. Idle is at 40% until oil at 40 C and CHT (at) 140-150 C. Runup is with the pitch full fine (forward) and at 70% with the mag check first then cycle the prop 3 times and run the left to right cockpit check. I'm ready to go aviating then.

Doc



--

viperdoc(at)mindspring.co
Guest

Posted: Tue Dec 04, 2007 11:33 am Post subject: Throttle setting at higher cruising altitudes

Walt,

The YAK50 manual calls for 70% and 400 mmHg on final. I personally tend to descend with the pitch set at 80%. Not necessarily for go around but for a "speed brake"! She will jump from 150 Kilo/sec to 170 kps in a heart beat if you lower the alpha by letting the nose drop during final turn. If I have to do a go round, 80% and 850 mmHG is more than enough power with the risk of torque rolling her a 100% and 850 mmHG. She will lift the left main off the ground if you push it suddenly for sure.

For the start I pull 14 blades with the intake open. If there is sluggish flow of oil out of the intake drain, I will prime with 4-6 strokes looking for fuel to lfow out of the intake. I then pull another 8-12 and wait until the oil stops draining out of the intake. After that, I close the intake, give it a couple of strokes of prime, and pull 4 blades stopping on the compression. Start is generally one blade tic to fire off. Idle is at 40% until oil at 40 C and CHT (at) 140-150 C. Runup is with the pitch full fine (forward) and at 70% with the mag check first then cycle the prop 3 times and run the left to right cockpit check. I'm ready to go aviating then.

Doc



--

mark.bitterlich(at)navy.m
Guest

Posted: Tue Dec 04, 2007 1:59 pm Post subject: Throttle setting at higher cruising altitudes

Hi Jan,  



 	  Quote: 	
		  1. before startup, we eventually heat the oil with a small electrical

"spiral" device (the things used for heating water in a cup). I
	


personally turn the prop AT LEAST 25 blades; prime left and right 4

times, pull the prop 5 or 6 blades; prime again the cylinders 2  to 3

times; the engine usually fires after I saw moving three to four blades

(three-bladed prop).



I've read some negative comments about directly heating oil with a

device that actually goes into the oil itself to heat it.  As memory

serves, it had something to do with condensation.  I can't swear to that

though!  Personally I use electric heating "pads" that are placed on the

exterior of the oil tank and heat the whole tank.  I do not have one,

but if you were to do this the RIGHT way, you'd also add one of these

pads to the engine oil sump, and if you were REALLY concerned, put one

somehow on the oil cooler.  In North Carolina it simply never gets that

cold really, so I have been fine with just heating the oil tank itself.

Oil in cylinders when it is cold is a serious problem in that it simply

doesn't want to come out very easily.  Especially true as well in the

intake tubes.  This seems to be more of a problem in the 50 than the 52

.. Due to tilt?  Maybe.  Anyway, I usually pull about 4-5 blades and

then prime a little simply because the gas tends to mix with the oil,

thin it and then allow it to drain out easier.  This is a personal

preference and is not based on any expert input.  I then pull it through

a whomp more times (as you suggested) then prime the crap out of it

again, pull it through another couple of blades and start.  Pretty much

the same sequence as yourself.  I have an intake drain kit installed.

When I prime the engine I want to see the extra fuel come out of that

tube.  Having that makes it pretty much impossible to over-prime.  



 	  Quote: 	
		  2. at startup, the prop control is fully fine (governor control lever

completely to the front), 
	




Yep.  

 	  Quote: 	
		  3. when engine started, I let it run at 42 % (with throttle control

very slowly up until 40 or 42 % is reached, prop all this time full
	


fine) until the proper temperatures are reached.



Ok.  



 	  Quote: 	
		  4. then I taxi to the holding point, prop still full fine, but reducing

the throttle a lot less than 40 %,just above idle, otherwise my Yak 50
	


rolls too fast



Ok



5. run-up tests: check first if the engine still has the proper

temperatures (oil above 40 degrees, CHT at 150 degrees); then throttle

up to 70 % for the magneto checks, and then 3 times governor control by

pulling back and forth the prop lever; not too fast, but firmly (with

the Extra 300 that I may fly, the owner asked me to do this prop checks

very quickly because they only have to take away the air bubbles in the

governor; he got this advise when he bought his Extra 300 new from the

factory; I suppose this makes sense for his specific governor

mechanism).



The prop check for the YAK aircraft is different.  They want you to set

a certain RPM and then pull the prop lever full aft and see that it

holds a certain RPM.  It is not a cycle back and forward, repeat three

times deal, but I can not address which way is better.  I will say that

I think you should hold it back to try and get warm oil into the prop

itself and that quick cycling MAY not do that.  Again, I really am not

sure.   



 	  Quote: 	
		   6. at take-off, my prop control is full fine, and I SLOWLY advance the

throttle to full power, so having the Yak 50 roll smoothly. I don't push
	


the stick forward, but keep it in the middle, slightly back, so that the

plane gets airborne from the three wheels at the same time. Then I lower

the nose, gear up, let speed go up; when at 500 feet, I reduce the RPM

to 82 % but leave the throttle full open. In cruise flight, I always

have the prop/throttle settings slightly "oversquare" i.e. 70 % prop, 75

throttle or 60/65.



Each person has his or her own method for the above.  I really am not

going to say "right or wrong" with anything you say.  It obviously works

and I do much the same myself.  Especially with the RPM method you just

mentioned.  

 	  Quote: 	
		  7. in final approach, I have the prop control at 70 % and use the

throttle (and nose position and trim) to establish the correct speed
	


(145 to 150 km/h, is what I need for a good three-pointer). I aim for

the numbers, and just above the numbers, I have the throttle completely

idle.



When landing, I always have the prop control full forward.  I only put

it there after the gear is down and I am slowed to near approach speed.

THEN I push the prop full forward.  Doing it that way keeps the prop

from reversing the load on the thrust bearing, and also has me

completely prepared for a go around.  



 	  Quote: 	
		  8. for run-down, I advance the throttle a bit, I put the prop governor

again at fully fine, and the throttle to 65 %, have it scavenge the oil
	


for 25 seconds, then I pull back the throttle to 43 %, shut down the

magneto's and immediately I advance the throttle fully. (in my

experience this helps to avoid big flames at the exhaust pipes; I've

seen this on several engines).



I do much the same, but reduce to idle before killing the mags...  I

believe your methods are so close to what the book calls for that there

is not reason to concern yourself in any way Jan.  Just my 2 cents. 



Mark

jan.mevis(at)informavia.b
Guest

Posted: Tue Dec 04, 2007 2:32 pm Post subject: Throttle setting at higher cruising altitudes

Thanks, Walt ! 



I used to put full fine with the 2-bladed prop. With My 3-bladed MT-prop,

it's somewhat easier to have 70 %, but I'll reconsider it !,



Jan



--

jan.mevis(at)informavia.b
Guest

Posted: Tue Dec 04, 2007 2:33 pm Post subject: Throttle setting at higher cruising altitudes

Thanks Mark! 



Jan



--

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