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rotax 912UL
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iworonko(at)cox.net
Guest

Posted: Tue Feb 19, 2008 6:44 pm Post subject: rotax 912UL

Hi Folks,

 after two years of rebuilding N58EW has been  inspected and is officially an airworthy aircraft. However, I cant get the Rotax  912 UL above 5000rpm. First tried it with GSC prop with the pitch reduced down  to 15 deg.

 Then I installed an IFA Ivo 3 blade prop, still  only 5000rpm. So I shortened it by 1" to 68" dia. , still only  5000rpm.

 Any ideas?

 thanks in advance 

 Eric    Speedster  N58EW

    [quote][b]

Sbennett3(at)aol.com
Guest

Posted: Tue Feb 19, 2008 7:37 pm Post subject: rotax 912UL

Bad tach ???  Steve  Bennett



Delicious ideas to please the pickiest eaters. Watch the video on AOL Living.

  [quote][b]

kitfoxpilot(at)msn.com
Guest

Posted: Tue Feb 19, 2008 7:47 pm Post subject: rotax 912UL

I to have the 912 but the ULS and I have 16 degrees pitch on warp drive prop and on the ground 5000rpm is all I get can't seem to get more out of it!

  	  Quote: 	
		    From: iworonko(at)cox.net

To: kitfox-list(at)matronics.com

Subject: Kitfox-List: rotax 912UL

Date: Tue, 19 Feb 2008 20:40:39 -0600

     Hi Folks,

 after two years of rebuilding N58EW has been inspected and is officially an airworthy aircraft. However, I cant get the Rotax 912 UL above 5000rpm. First tried it with GSC prop with the pitch reduced down to 15 deg.

 Then I installed an IFA Ivo 3 blade prop, still only 5000rpm. So I shortened it by 1" to 68" dia. , still only 5000rpm.

 Any ideas?

 thanks in advance 

 Eric    Speedster N58EW

 	  Quote: 	

arget=_blank>http://www.matronics.com/Navigator?Kitfox-List

p://forums.matronics.com

blank>http://www.matronics.com/contribution

Connect and share in new ways with Windows Live. Get it now!  [quote][b]

iworonko(at)cox.net
Guest

Posted: Tue Feb 19, 2008 7:57 pm Post subject: rotax 912UL

not the tach, I double checked it with two  different optical tachs.

 and the carbs are synchronized

 Eric

    [quote][b]

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Tue Feb 19, 2008 11:26 pm Post subject: rotax 912UL

On Feb 20, 2008, at 4:44 AM, RAY Gignac wrote:

 	  Quote: 	
		    I to have the 912 but the ULS and I have 16 degrees pitch on warp 

 drive prop and on the ground 5000rpm is all I get can't seem to get 

 more out of it!


	


I can't say for the Rotax because I have a Jabiru but ... on-the-ground 

static Wide-Open-Throttle RPM,  initial climb WOT RPM and level flight 

WOT RPM are three distinct things with quite a difference. Maybe Ray is 

right, Eric; 5,000 might be good enough.



Cheers,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200

_________________
Kitfox 3 - Jabiru 2200

propellerdesign(at)tele2.
Guest

Posted: Tue Feb 19, 2008 11:47 pm Post subject: rotax 912UL

So, what RPM is you supposed to see static?  

 normally minimum static rpm is 85% of max, and up  to 90% - 4930 - 5220 would be normal, 

 Pitch 15 deg, Ok but where on the blade?  

 Gear ratio 2,273 - 2550 rpm on prop, 

 Max speed 110 mph? 

 = 45,5" pitch / 68" diam = 15,87 degree at  75% of the radii! 

 Not at tip!  (tip is 12 deg.) (depending of  blade twist)

  

 With a wood bar test club, instead of propeller  with diameter 1108 mm (43,62") and a square (thick and wide) 73,9 mm (2,91")  section, it will produce 80 HP at 5800/2552 RPM

 It have to be balanced! and doublers at the hub,  each side.

 You have a planer in basement? or guy next door? or  that guy down the street? yes him with the beautiful wife!

  

 Jan

 [quote]   ---

propellerdesign(at)tele2.
Guest

Posted: Wed Feb 20, 2008 12:03 am Post subject: rotax 912UL

Michel,



Hur hurtig er deres maskin med Jab'n?

(top speed WOT with Jabiru?)



Nabo

Jan 

---

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Wed Feb 20, 2008 2:33 am Post subject: rotax 912UL

Hej Jan,



 	  Quote: 	
		   From: JC Propeller Design [propellerdesign(at)tele2.se] 

 Hur hurtig er deres maskin med Jab'n?

 (top speed WOT with Jabiru?)


	


The answer is: too fast! My model 3 has a Vne of 100 MPH and at level and WOT it takes only seconds before reach it. The nominal max RPM of the Jabiru is 3,300 RPM but I have never seen it over 3,050, which is what I get for the few seconds before reaching Vne. On initial climb at WOT, I read 2,900 RPM and static, on the ground, about 2800 RPM. I usually cruise at 2,600 RPM and it gives me about 85 MPH (72 knots), which is a nice and economical speed. My Jabiru propeller has a pitch for cruise and not for sharp initial climb. But I fly from a long runway and ... anyway, I am in the air in only a couple of hundred yards.



Vennlig hilsen,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200

<pre><b><font size  color="#000000" face="courier new,courier">

_________________
Kitfox 3 - Jabiru 2200

Fox5flyer
Guest

Posted: Wed Feb 20, 2008 4:37 am Post subject: rotax 912UL

Generally the inability to get past a certain rpm  regardless of load is breathing.  Think of the NASCAR restrictor  plates.  

 Has it ever gone past 5000 or is this a new  phenomenon?  Have you made any changes to the engine or components during  the rebuild?  Different air filters?  Carb heat box?  Who did the  rebuild and have you consulted with them?

  

 Deke Morisse

Mikado Michigan

S5/Subaru/CAP  355+ TT

"The aim of an argument or discussion should not be victory, but  progress."

- Joseph Joubert

  

 

 



 [quote]   ---

propellerdesign(at)tele2.
Guest

Posted: Wed Feb 20, 2008 7:25 am Post subject: rotax 912UL

Michael,



Make sense.

2800/3300 =0,85% static

85 mph / 2600 * 3050 = 100 mph

3300 = 108 mph fictive top speed

Pitch 34,5" - 35"

You use 40 HP at 85MPH, 12,6 L/h??



Lige måde

Jan



---

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Wed Feb 20, 2008 12:04 pm Post subject: rotax 912UL

On Feb 20, 2008, at 4:22 PM, JC Propeller Design wrote:

 	  Quote: 	
		   Pitch 34,5" - 35"

 You use 40 HP at 85MPH, 12,6 L/h??


	


The prop is a two-bladed fixed pitch Jabiru 60 by 28", Jan. For the 

fuel, I am not very observant but from my trip to Belgium two years 

ago, I reckon something like 13 liters per hour. I don't have the 

economy kit for the carburettor, though. Not everybody is pleased with 

it and ... I don't repair something that works.



Hej då,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200

_________________
Kitfox 3 - Jabiru 2200

propellerdesign(at)tele2.
Guest

Posted: Wed Feb 20, 2008 3:56 pm Post subject: rotax 912UL

12,6 or 13 l/h is close enough, if you calc. in taxi and WOT climb also we 

are right on.



Pitch sounds a bit low, but pitch is a relative norm (as is intelligence) 

and depends on thickness of blade. Thick airfoil?



Jan

---

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Wed Feb 20, 2008 6:17 pm Post subject: rotax 912UL

Michel, did you hit the wrong key?....28"? I thought yours was closer  

to 38".

Lynn Matteson

Grass Lake, Michigan

Kitfox IV Speedster  w/Jabiru 2200

flying w/475+ hrs

do not archive

On Feb 20, 2008, at 3:00 PM, Michel Verheughe wrote:

 	  Quote: 	

 On Feb 20, 2008, at 4:22 PM, JC Propeller Design wrote:

> Pitch 34,5" - 35"

> You use 40 HP at 85MPH, 12,6 L/h??

 The prop is a two-bladed fixed pitch Jabiru 60 by 28", Jan. For the  

 fuel, I am not very observant but from my trip to Belgium two years  

 ago, I reckon something like 13 liters per hour. I don't have the  

 economy kit for the carburettor, though. Not everybody is pleased  

 with it and ... I don't repair something that works.

 Hej då,

 Michel Verheughe

 Norway

 Kitfox 3 - Jabiru 2200

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Jim Shumaker

Joined: 09 Jan 2006
Posts: 106

Posted: Wed Feb 20, 2008 8:11 pm Post subject: rotax 912UL

Eric

  

 15 degrees can be a lot on a Warp drive prop, when measured at the tip.  Warp drive suggests flatenning the pitch until the desired rpm is acheived, static.  That is different for the taper tip and the full width tip.  The taper tip is generally set to redline at static.  After acheiving the desired rpm then compare to other pilots.  I believe I am at about 8 degrees at the tip.  If you have trouble getting rpm then it could be the butterflies are not opening all the way.  Or the ducting to the carbs (if you have carb heat) could be restictive.

  

 Jim Shumaker

 Kitfox III, 912 UL

 California

 ---

_________________
Jim Shumaker

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Wed Feb 20, 2008 11:47 pm Post subject: rotax 912UL

 	  Quote: 	
		   From: Lynn Matteson [lynnmatt(at)jps.net] 

 Michel, did you hit the wrong key?....28"? I thought yours was closer  

 to 38".


	


Oops! Yes, wrong key! It's 38 inches. Thanks for watching my steps, friend!



Cheers,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200

<pre><b><font size  color="#000000" face="courier new,courier">

_________________
Kitfox 3 - Jabiru 2200

dcsfoto

Joined: 24 Aug 2006
Posts: 120

Posted: Thu Feb 21, 2008 10:34 am Post subject: Re: rotax 912UL

on my model 3 it was set at 5000 rpm and I had good climb and to much cruse speed. now set at 5400 ( static) and cruse is down but climb is great.



David Model 3 and 7

Fox5flyer
Guest

Posted: Thu Feb 21, 2008 11:07 am Post subject: rotax 912UL

How can one have "too much cruise speed"  ?  

Deke



do not archive



---

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Thu Feb 21, 2008 12:36 pm Post subject: rotax 912UL

 	  Quote: 	
		   From: fox5flyer [fox5flyer(at)idealwifi.net] 

 How can one have "too much cruise speed"  ?  


	


Good question, Deke. Compared to some of the other members of this list, I have very little experience; I started flying five years ago and have about 350 hours on my Kitfox.

 	  Quote: 	
		  From what I understand, I can fly a little bit faster than 100 MPH, my Vne, without much risk. But when it gets a bit turbulent - and in the summer, it's more the rule than the exception - the needle moves fast in all directions. The 'book' says that in turbulent conditions, one should fly under Va, the manoeuvre speed. For me that's 70 MPH. So, when it gets choppy, I pull the throttle. Now, what is 'turbulent?' I certainly don't feel like a daredevil; rather a sissy. Better safe than sorry. So, I fly at an average cruise speed of about 85 MPH.


	


Cheers,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200

<pre><b><font size  color="#000000" face="courier new,courier">

_________________
Kitfox 3 - Jabiru 2200

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Thu Feb 21, 2008 2:20 pm Post subject: rotax 912UL

Only if you're a Sport Pilot.... : )



Or if you're Michel. : )



Lynn

do not archive



On Feb 21, 2008, at 2:02 PM, fox5flyer wrote:



[quote] 

 <fox5flyer(at)idealwifi.net>



 How can one have "too much cruise speed"  ?  

 Deke



 do not archive



 ---

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Rex Hefferan

Joined: 10 Jan 2006
Posts: 147
Location: Olney Springs, Colorado USA "NOT a Kitpig"

Posted: Thu Feb 21, 2008 2:43 pm Post subject: rotax 912UL

Seriously, it seems possible to clean up the drag on some of our kit 

planes enough that one could exceed Vne in a high cruise.

Rexinator =-O

 Colorado

do not archive



Lynn Matteson wrote:



[quote] 



 Only if you're a Sport Pilot.... : )



 Or if you're Michel. : )



 Lynn

 do not archive



 On Feb 21, 2008, at 2:02 PM, fox5flyer wrote:



> 

> <fox5flyer(at)idealwifi.net>

>

> How can one have "too much cruise speed"  ?  

> Deke

>

> do not archive

>

> ---

_________________
Rex
N740GP - M2/582
Colorado

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