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jlivsey(at)bigpond.com
Guest

Posted: Sat Dec 30, 2006 3:38 pm Post subject: Sensenich Composite Propeller

Hi list,



I've just fitted one of the Sensenich composite propellers to my 

CH601-HDS running a Jabiru 3300. I would be interested to hear from 

anyone that has fitted one to a similar set-up as regards what sort of 

performance and engine RPM they have set-up.



For interest I obtain the following figures (Solo half fuel)



Climb RPM at 70KIAS 3050, RofC about 1400 FPM



Max S&L RPM 3225 at 125KIAS.



Cruise at 2800 RPM 110KIAS.



All figures at around 2500 ASL



The speed figures were straight of the A/S indicator so probably not 

totally accurate and it was a bumpy day.



regards john

p.mulwitz(at)worldnet.att
Guest

Posted: Sat Dec 30, 2006 4:19 pm Post subject: Sensenich Composite Propeller

Hi John,



Is this the ground adjustable propeller?  Did you only try one pitch setting?



I am not in the air yet, but I have heard much higher cruise numbers 

from others with HDS and Jabiru 3300 combinations.



Paul

XL fuselage

do not archive



At 03:36 PM 12/30/2006, you wrote:

 	  Quote: 	
		  



Hi list,



I've just fitted one of the Sensenich composite propellers to my 

CH601-HDS running a Jabiru 3300. I would be interested to hear from 

anyone that has fitted one to a similar set-up as regards what sort 

of performance and engine RPM they have set-up.



For interest I obtain the following figures (Solo half fuel)



Climb RPM at 70KIAS 3050, RofC about 1400 FPM



Max S&L RPM 3225 at 125KIAS.



Cruise at 2800 RPM 110KIAS.



All figures at around 2500 ASL



The speed figures were straight of the A/S indicator so probably not 

totally accurate and it was a bumpy day.



regards john

jlivsey(at)bigpond.com
Guest

Posted: Sat Dec 30, 2006 5:08 pm Post subject: Sensenich Composite Propeller

Paul,



    Yes its ground adjustable but getting it "right" is tricky as the amount of adjustment is so fine,

    probably about 0.25mm gave me a 150 RPM change.



    John



    Hi John,



    Is this the ground adjustable propeller?  Did you only try one pitch setting?



    I am not in the air yet, but I have heard much higher cruise numbers 

    from others with HDS and Jabiru 3300 combinations.



    Paul

    XL fuselage

    do not archive



    At 03:36 PM 12/30/2006, you wrote:

    >

    >Hi list,

    >

    >I've just fitted one of the Sensenich composite propellers to my 

    >CH601-HDS running a Jabiru 3300. I would be interested to hear from 

    >anyone that has fitted one to a similar set-up as regards what sort 

    >of performance and engine RPM they have set-up.

    >

    >For interest I obtain the following figures (Solo half fuel)

    >

    >Climb RPM at 70KIAS 3050, RofC about 1400 FPM

    >

    >Max S&L RPM 3225 at 125KIAS.

    >

    >Cruise at 2800 RPM 110KIAS.

    >

    >All figures at around 2500 ASL

    >

    >The speed figures were straight of the A/S indicator so probably not 

    >totally accurate and it was a bumpy day.

    >

    >regards john

      



------------------------------------------------------------------------

craig(at)craigandjean.com
Guest

Posted: Sat Dec 30, 2006 5:23 pm Post subject: Sensenich Composite Propeller

 	  Quote: 	
		  > 0.25mm gave me a 150 RPM change.


	


Is that 0.25mm on the dial and scale on the front of the hub? On mine that

looks like a pretty coarse and sloppy adjustment. I think a digital level on

the blades might be a better way to set the pitch (or at least to get both

blades consistent). But I have yet to spin the prop.



-- Craig

p.mulwitz(at)worldnet.att
Guest

Posted: Sat Dec 30, 2006 6:58 pm Post subject: Sensenich Composite Propeller

Hi John,



I am still on the theory stage, so you should take my comments as 

possibilities rather than facts.



As I understand it, your cruise speed is severely limited by the 

pitch setting on the propeller.  As you gain speed the relative 

"Bite" of the prop is reduced, and when you approach the speed where 

there is no "Bite" left you simply stop accelerating.



More theory - if you adjust the propeller for maximum static RPM I 

think your pitch will be too low for high speed acceleration.  There 

is some ideal static RPM with full throttle that is considerably 

lower than the engine's red line.



The price you pay for higher pitch is slower acceleration at low 

speed and reduced "Climb" performance.  If you reduce the pitch too 

much you will accelerate nicely from stopped but may never get above 

stall speed.



I don't know how the prop is supposed to be set, but I imagine there 

is need for many trials paying attention to takeoff runway needed and 

cruise speed at max cruise RPM.  This could be a very long and 

painful process, but in the end you will have achieved the best 

possible performance from your plane combined with your propeller.



This whole process is automatic if you have a constant speed 

propeller.  However, those little toys are very expensive.  They are 

also not allowed on LSA - probably because the great powers in the 

FAA bureaucracy consider them a complexity beyond beginning 

pilots.  That leaves you with some sort of trial and error process to 

learn where your prop is best set for the performance you want.



I would be very interested to know what cruise speeds you can reach 

with your power plant.  I am planning on using the Jabiru engine with 

fixed pitch prop for initial testing and then switching to the ground 

adjustable prop after I finish phase 1 to look for the best cruise 

performance I can get for cross country flying.  Of course I still 

want reasonable takeoff and climb performance so I might just stick 

with the wood prop if the performance seems good.



Good luck,



Paul

XL fuselage



At 05:07 PM 12/30/2006, you wrote:

 	  Quote: 	
		  



    Paul,



    Yes its ground adjustable but getting it "right" is tricky as 

 the amount of adjustment is so fine,

    probably about 0.25mm gave me a 150 RPM change.



    John



    Hi John,



    Is this the ground adjustable propeller?  Did you only try one 

 pitch setting?



    I am not in the air yet, but I have heard much higher cruise 

 numbers    from others with HDS and Jabiru 3300 combinations.



    Paul

    XL fuselage

    do not archive

btucke73(at)yahoo.com
Guest

Posted: Mon Jan 01, 2007 8:38 pm Post subject: Sensenich Composite Propeller

John,



     Since nobody has chimed in on the Jab HDS

question, I will give a little comparison from Corvair

HDS.  I am getting about 120 cruise (without wheel

pants or any aero cleanup at all), and about 800 fpm

climb.  It sounds like you are getting a good climb

rate, with slightly lower than expected cruise speed. 

I would add a little pitch, and see what happens.  If

your plane has pants, you might expect more like 130

mph with the extra HP and less weight, when compared

to mine.  



VR/



Brandon Tucker

__________________________________________________

p.mulwitz(at)worldnet.att
Guest

Posted: Mon Jan 01, 2007 9:12 pm Post subject: Sensenich Composite Propeller

Hi Brandon,



I have been trying to follow this thread closely, and wonder if there 

is some confusion over the actual airspeeds achieved.



If I got your last post correctly, you suggest the HDS might achieve 

130 mph, but John's original post already claims nearly 140 mph.  If 

I have it correctly, he should get higher cruise speeds - over 150 

mph - if he increases the pitch of his propeller to the ideal amount.



The reason I think there is some confusion is your message talks 

about mph while John's talks about knots (KIAS).



Best regards,



Paul

XL fuselage



At 08:37 PM 1/1/2007, you wrote:

 	  Quote: 	
		  



John,



      Since nobody has chimed in on the Jab HDS

question, I will give a little comparison from Corvair

HDS.  I am getting about 120 cruise (without wheel

pants or any aero cleanup at all), and about 800 fpm

climb.  It sounds like you are getting a good climb

rate, with slightly lower than expected cruise speed.

I would add a little pitch, and see what happens.  If

your plane has pants, you might expect more like 130

mph with the extra HP and less weight, when compared

to mine.



VR/



Brandon Tucker

btucke73(at)yahoo.com
Guest

Posted: Tue Jan 02, 2007 7:55 am Post subject: Sensenich Composite Propeller

Paul,



     I did not notice the Knots.  I would question the

airspeed calibration of any HDS showing 125 knots

cruise, even with a Jabiru -or congratulate the

builder for the ability to perform magic.



VR/



Brandon



__________________________________________________

larry(at)macsmachine.com
Guest

Posted: Tue Jan 02, 2007 8:47 am Post subject: Sensenich Composite Propeller

Brandon,

With the described HDS, no pants, unknown pitch setting etc, the 125 

knots might be difficult

to reach, but the objective of getting 130 mph plus is not magic, even 

with the humble Subaru.

You need a good set of pants, gearbox fairings, step tube fairings, a 

full core spinner, a 17 inch pitch

in a 70 inch prop, a clean aircraft and 100 hp to get there. There's no 

magic, just persistent effort

at cleaning up the HDS.  The latest finding was that the elevator trim 

at the highest speed needs to be

readjusted to allow the lift to move further back and that last 

adjustment reduces drag a little bit more.

I believe the HDS might be capable of even more with adjustment of the 

prop, trim etc.

In any case, the XLs thin wing will do better with the same effort, etc.

Read my journal section 11, December 27 and the latest GPS airspeed 

check and you see that it's

possible if things are in proper adjustment.

Respectfully,

Larry McFarland - 601HDS at www.macsmachine.com

Brandon Tucker wrote:

 	  Quote: 	
		   



 Paul,



      I did not notice the Knots.  I would question the

 airspeed calibration of any HDS showing 125 knots

 cruise, even with a Jabiru -or congratulate the

 builder for the ability to perform magic.



 VR/



 Brandon

p.mulwitz(at)worldnet.att
Guest

Posted: Tue Jan 02, 2007 9:14 am Post subject: Sensenich Composite Propeller

Hi Brandon,



I wonder why you feel 125 knots is fast for an HDS.  The only other 

data points I have from other owners with the Jabiru mounted on an 

HDS report over 150 mph cruise.



I am still waiting for some good data on the cruise speeds achieved 

with the Jabiru on an XL.  Since ZAC reports faster speeds for the XL 

than the HDS I am hoping for numbers in the 160 mph range.  This is 

based on the HDS numbers I have heard and the assumption of a 

"Cruise" prop setting.



Perhaps you know something I don't . . .



Paul

do not archive



At 07:54 AM 1/2/2007, you wrote:

 	  Quote: 	
		  



Paul,



      I did not notice the Knots.  I would question the

airspeed calibration of any HDS showing 125 knots

cruise, even with a Jabiru -or congratulate the

builder for the ability to perform magic.



VR/



Brandon



__


	


-

btucke73(at)yahoo.com
Guest

Posted: Tue Jan 02, 2007 3:56 pm Post subject: Sensenich Composite Propeller

Larry,



     I agree that 130 mph is not magic, and feel that

with some cleanup work, I will get mine there as well.

 However, 125 kts seems quite unrealistic for the HDS.

 Quick math...  150 mph...  



     If there is anyone on this list getting 150 mph

in an HDS at 75% cruise, GPS calibrated, please chime

in...  



VR/



Brandon



__________________________________________________

paulhartl(at)cox.net
Guest

Posted: Thu Jan 04, 2007 9:47 am Post subject: Sensenich Composite Propeller

List,

  

 Maybe I should chime in on this discussion of Jab-powered HDS speeds,  as I have 82 hours now with mine.  

  

 I have reported data on my Jab-powered HDS several times on this  list,  but the numbers that many would like to see seem to have precedence  

 over real numbers.  The HDS's fat wing, no matter how short, is still  a pretty draggy affair, and has kept my cruise numbers to about 

 105 knots (120 mph) (at) 4.2 gph, (at) 2650 RPM, typically at 7000' MSL (I live  in Idaho, where the land rises pretty high!).  I can push the throttle  

 open to see about 130 mph at somewhere around 2850 RPM, but fuel  consumption shoots to an ungodly 7.5 gph and my range diminishes to 

 ridiculous numbers (20 gallons fuel capacity).  My plane weighs in at  705 lbs empty, is unpainted, and has ZAC's original "fat" wheel pants - oh,  

 and I faired over the main landing gear boxes, too.  I have the Jabiru  3300A and Jab's recommended Sensenich wood prop.

  

 Slimmer wheel pants might help a little, as would fairing the struts a bit,  but I think the most improvement would be seen with an in-flight adjustable  prop.  

 However, Jabiru engines need a lot of cooling air funneled into the cowl  openings, which is why they recommend the particular Sensenich wood prop that  

 they do (can't remember the model number right now), which has a lot of  pitch up close to the hub (unlike many others), so I would be very careful  about

 choosing a different prop, and would definitely consult with Jab before  doing so.  The plane climbs very well with this prop - even at high  altitudes - 

 so my guess is that the pitch is optimized for climb over cruise, and  a well-matched in-flight adjustable prop might get 5 to 10 mph faster cruise  without

 sacrificing climb - but I greatly doubt much more than that, as drags goes  up with the square of velocity - and a fat wing is a fat wing.  XL owners  definitely

 have the advantage in that department!

  

  Paul Hartl, N414PZ, 601 HDS, Jab 3300A

 82 hours, 96 landings - lots of fun!

 Hailey, Idaho

 http://members.cox.net/paulhartl/ 

   [quote][b]

Tim Juhl

Joined: 21 Mar 2006
Posts: 488
Location: "Thumb" of Michigan

Posted: Thu Jan 04, 2007 5:14 pm Post subject: Re: Sensenich Composite Propeller

I attended a weekend class at USJabiru on installing a 3300 in an XL.  Pete spent a fair amount of time talking about tuning the carb to match the airframe and propeller.   He said that with the economizer kit and a change in needle jet size that good results have been achieved at about 2850 RPM -  ie.  peak egt (about 1400Â°) and 5 gph economy.   The new DVD from Homebuilthelp.com has his talk on it and you might find it informative.



Tim

_________________
______________
CFII
Champ L16A flying
Zodiac XL - Jabiru 3300A
Almost done! It'll fly in spring!

btucke73(at)yahoo.com
Guest

Posted: Thu Jan 04, 2007 6:22 pm Post subject: Sensenich Composite Propeller

I got an off-list email response from an HDS / Jab

3300 owner who is reporting the exact numbers that I

am seeing in my Corvair.  No aerodynamic clean up is

showing 120 mph at 2750 rpm and 130 mph at 2850 in the

Jabiru, and 120 at 2900 and 130 at 3000 in the

Corvair.  Both have GPS units installed, and have been

through numerous calibration runs.  



VR/



Brandon Tucker

601 HDS / TD / Corvair

46 hours



__________________________________________________

lgingell

Joined: 10 Jan 2006
Posts: 50
Location: Lake California Airpark 68CA

Posted: Thu Jan 04, 2007 6:57 pm Post subject: Re: Sensenich Composite Propeller

John-I'm jealous mate! I have a wood Sensenich fixed prop!  Sounds like you are maybe in quite a climb fine pitch to me.



Jab owners-Yes, Pete does seem to have some good points in the HomeBuiltHELP DVD.   I have a Sensenich 64ZKZ51 (think thats right) in my 3300 powerered XL, anyway, quite a cruise prop. I see 2600 rpm on takeoff, and my EGT's peak in the 1380's at 2650rpm.  I'm usually indicating something like 108-110Knots at that RPM, and around 5GPH. 

I can go a *lot* faster, but the fuel goes up, and EGT's go down. Its gets awfully rich.  I can _just_ about get 3100rpm level (almost) - so that gives you an idea of how my prop is (and I'm glad it is quite a cruise pitch, since I can easily get way over 1000fpm solo - probably closer to 1500 without going too slow).



Apparently i should be seeing my best results at around 2850rpm. If I could get to this RPM before my fuel burn took a drastic climb (and my EGT's dropped), then I'd pick up quite a bit of range.



I'm planning on removing my carb, checking the mid-jet, and ordering a smaller one sometime soon, per Pete's 'Carb tuning' discussion.

Cheers,



..lance

Lake California Airpark (68CA)

http://lancegingell.com/plane.asp 

XL/Jab 3300/Sensenich wood prop/Dynon EMS/EFIS/Kitchen sink/etc.

_________________
Zodiac XL/Jab 3300
http://lancegingell.com

n801bh(at)netzero.com
Guest

Posted: Thu Jan 04, 2007 7:32 pm Post subject: Sensenich Composite Propeller

Pardon me if I am getting this wrong, but,,, Am I safe to assume you guys with the Jab set up cannot change the mixture inflight?.  

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- "lgingell" <lgingell(at)matrix-logic.com> wrote:

--> Zenith-List message posted by: "lgingell" <lgingell(at)matrix-logic.com>



John-I'm jealous mate! I have a wood Sensenich fixed prop!  Sounds like you are maybe in quite a climb fine pitch to me.



Jab owners-Yes, Pete does seem to have some good points in the HomeBuiltHELP DVD.   I have a Sensenich 64ZKZ51 (think thats right) in my 3300 powerered XL, anyway, quite a cruise prop. I see 2600 rpm on takeoff, and my EGT's peak in the 1380's at 2650rpm.  I'm usually indicating something like 108-110Knots at that RPM, and around 5GPH. 

I can go a *lot* faster, but the fuel goes up, and EGT's go down. Its gets awfully rich.  I can _just_ about get 3100rpm level (almost) - so that gives you an idea of how my prop is (and I'm glad it is quite a cruise pitch, since I can easily get way over 1000fpm solo - probably closer to 1500 without going too slow).



Apparently i should be seeing my best results at around 2850rpm. If I could get to this RPM before my fuel burn took a drastic climb (and my EGT's dropped), then I'd pick up quite a bit of range.



I'm planning on removing my carb, checking the mid-jet, and ordering a smaller one sometime soon, per Pete's 'Carb tuning' discussion.

Cheers,



..lance

Lake California Airpark (68CA)

http://lancegingell.com/plane.asp 

XL/Jab 3300/Sensenich wood prop/Dynon EMS/EFIS/Kitchen sink/etc.



--------

Zodiac XL/Jab 3300

http://lancegingell.com/plane.asp





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   [quote][b]

amyvega2005(at)earthlink.
Guest

Posted: Fri Jan 05, 2007 7:30 am Post subject: Sensenich Composite Propeller

Ben,

The Jabiru as well as some Rotax have an altitude compensating Carburator. hence no mixture knob just Throttle and carb heat.

Juan



--

craig(at)craigandjean.com
Guest

Posted: Fri Jan 05, 2007 9:53 am Post subject: Sensenich Composite Propeller

 	  Quote: 	
		  > I got an off-list email response from an HDS / Jab 3300 owner who is

reporting the exact numbers that I am seeing in my Corvair.  No aerodynamic
	


clean up is showing 120 mph at 2750 rpm and 130 mph at 2850 in the Jabiru,

and 120 at 2900 and 130 at 3000 in the Corvair.  Both have GPS units

installed, and have been through numerous calibration runs.  



Interesting - that seems to say that the "100 hp" Corvair is doing as well

as the "120 hp" Jabiru. And the Jabiru is lighter!



Brandon - yours is a 2700cc Corvair, not the 3100cc - right?



-- Craig

craig(at)craigandjean.com
Guest

Posted: Fri Jan 05, 2007 10:17 am Post subject: Sensenich Composite Propeller

The Bing also has a choke.



Some switch the Bing for an Ellison to gain a mixture control and for other

reasons.



-- Craig

crvsecretary(at)aol.com
Guest

Posted: Fri Jan 05, 2007 10:41 am Post subject: Sensenich Composite Propeller

Hello Craig:

    

   Not to be picky, but a Bing Constant-Velocity (CV) carb does NOT have a choke - it has an enrichment circuit which does NOT block off the flow of air through the throat, instead, it allows supplimental fuel into the airstream ONLY when the throttle is fully CLOSED.

    

   It took me a long time to truely understand the Bing CV carb.  Virtually every BMW motorcycle in the "R" boxer twin series uses two of them.  Aside from starting, idle, and crossover circuits, the heavy lifting in the Bing CV carb is done with a moveable slide that rises up and down by responding to VACUUM in the carb throat.  A strong vacuum during WOT operation pulls the slide up allowing a needle attached to the bottom of the slide to pull way out of the main jet and that allows a lot of fuel to mix with the large volume of air going through the carb.  Also, the air moving through the venturi is at a Constant Velocity (CV carb, remember?) since the area of the venturi changes with the position of the slide.

    

   However, at high altitudes where the air is thinner the slide does not pull up as far due to less vacuum, and the needle does not pull out of the main jet as far.  This is your high-altitude mixture control.

    

   The authority on these carbs is The Bing Doctor and the bible is the Manual available here:

    

   http://www.bingcarburetor.com/manual.html

    

   Absolutely the final word on Bing.

    

   Tracy Smith

   Naugatuck, CT

   601XL N458XL (reserved)

    

    

    

    

  

 --

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