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Static rpm - warp drive/912ULS
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Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Sun Mar 15, 2009 4:14 am Post subject: Re: Static rpm - warp drive/912ULS

Lucien,



You are right about the speed range not leaving us much choice. That is the bane of most fixed pitch props on aircraft with a wide speed range. However, 4900 rpm is not really lugging the 912. At full throttle and 4900 rpm, the 912UL is producing about 92-93% of max continuous cruise power. 



Based on what I keep reading about the Warp taper tip, I'm inclined toward that to replace the Tennessee woody climb prop on our RANS.

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Sun Mar 15, 2009 6:02 am Post subject: Static rpm - warp drive/912ULS

> We plan to change the climb prop eventually for an adjustable pitch. 

We've been doing a lot of other refinements that were more critical but the 

prop change is getting closer to the top of the list.

 	  Quote: 	
		  

 --------

 Thom Riddle


	




Which Rans are you guys flying?



Flying at extreme altitudes will pull my WOT rpm down to 5,000 rpm.  This 

usually happens out West doing mountain flying.  Propped correctly for 410 

MSL, I'll be over propped by the time I reach West Texas.



I've never flown my 912 powered airplane with anything except a taper tip 

Warp Drive.  I did fly the 582 with the GSC Prop.  It flew good, but was not 

the most durable prop I have ever flown with.



john h

mkIII

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Sun Mar 15, 2009 6:14 am Post subject: Re: Static rpm - warp drive/912ULS

John,



S6-S 912UL taildragger. With the climb prop in the eastern lowlands it gets about  105 mph TAS at 5500 rpm in straight and level flight with some throttle left. During one of the rare clear sky days we had several weeks ago I took it to 10,500 msl and it would still pull over 5500 rpm but that was a cold day so it was probably only about 7,000' density altitude.



It is beginning to warm up here with today forecast around 55F so pretty soon we'll have some close to standard days. I want to see at what DA this prop is optimized for before we switch it out.

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

by0ung(at)brigham.net
Guest

Posted: Sun Mar 15, 2009 6:43 am Post subject: Static rpm - warp drive/912ULS

John

 When I called and talked with Darrell when I ordered my warp drive...   he

told me that at my altitude he recommended the 68 inch standard tip for my

912 ul.  So I guess I don't know what difference the taper tip would do for

me.  Interesting he also mentioned the standard tip was a better choice  for

sea planes.



Boyd

MKIIIC

Utah.   

4226 ft Msl



 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>>>>>


	


I've never flown my 912 powered airplane with anything except a taper tip 

Warp Drive.  I did fly the 582 with the GSC Prop.  It flew good, but was not



the most durable prop I have ever flown with.



john h

mkIII

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Mar 15, 2009 6:50 am Post subject: Re: Static rpm - warp drive/912ULS

 	  Thom Riddle wrote: 	
		  John,



S6-S 912UL taildragger. With the climb prop in the eastern lowlands it gets about  105 mph TAS at 5500 rpm in straight and level flight with some throttle left. During one of the rare clear sky days we had several weeks ago I took it to 10,500 msl and it would still pull over 5500 rpm but that was a cold day so it was probably only about 7,000' density altitude.



It is beginning to warm up here with today forecast around 55F so pretty soon we'll have some close to standard days. I want to see at what DA this prop is optimized for before we switch it out. 	




For what it's worth, good friend of mine back in TX (hmm.. I should call him and see if he'd consent to be part of the possible MV Posse) has an S6ES with the 80 horse 912. He runs a WD 2 blade, tho I don't recall if it's the taper tip.



As for altitude, when I moved here to northern NM, I brought the FSII with me. The only thing I had to change out was the main jets, it still ran at the same rpms without having to adjust the prop. It also had the WD 68" 3 blade. 



I don't recall what I had to change pitch-wise on the titan when I flew it here from nebraska. 



Both planes, tho, experienced huge drops in climb of course. The FSII went down from about 800-900 fpm to about 300fpm. The titan now does about 900 fpm down from almost 1800fpm near sea level.



Once in the FSII I made it past pattern altitude to almost 8500 MSL (a typical kicking-around-the-area altitude of 1500 to 2000 AGL), cliimb was down to about 100 fpm. Still pretty good given that the plane was a little heavy....



LS

_________________
LS
Titan II SS

aslsa.rng(at)gmail.com
Guest

Posted: Sun Mar 15, 2009 7:08 am Post subject: Static rpm - warp drive/912ULS

Lucien, When you think about lugging the 912, remember, 1, this is a four stoke engine, much more robust when dealing with prop loading than a 2 stroke, and 2, Rotax designed the 912 series engines to be capable of using constant speed propellers. Just make sure you keep the CHT's below max. A new set of heads is over half the cost of the engine. 

Rick

On Sun, Mar 15, 2009 at 9:50 AM, lucien <lstavenhagen(at)hotmail.com (lstavenhagen(at)hotmail.com)> wrote:

[quote] --> Kolb-List message posted by: "lucien" <lstavenhagen(at)hotmail.com (lstavenhagen(at)hotmail.com)>

 Thom Riddle wrote:

 > John,

 >

 > S6-S 912UL taildragger. With the climb prop in the eastern lowlands it gets about  105 mph TAS at 5500 rpm in straight and level flight with some throttle left. During one of the rare clear sky days we had several weeks ago I took it to 10,500 msl and it would still pull over 5500 rpm but that was a cold day so it was probably only about 7,000' density altitude.

  >

 > It is beginning to warm up here with today forecast around 55F so pretty soon we'll have some close to standard days. I want to see at what DA this prop is optimized for before we switch it out.

 For what it's worth, good friend of mine back in TX (hmm.. I should call him and see if he'd consent to be part of the possible MV Posse) has an S6ES with the 80 horse 912. He runs a WD 2 blade, tho I don't recall if it's the taper tip.

 As for altitude, when I moved here to northern NM, I brought the FSII with me. The only thing I had to change out was the main jets, it still ran at the same rpms without having to adjust the prop. It also had the WD 68" 3 blade.

 I don't recall what I had to change pitch-wise on the titan when I flew it here from nebraska.

 Both planes, tho, experienced huge drops in climb of course. The FSII went down from about 800-900 fpm to about 300fpm. The titan now does about 900 fpm down from almost 1800fpm near sea level.

 Once in the FSII I made it past pattern altitude to almost 8500 MSL (a typical kicking-around-the-area altitude of 1500 to 2000 AGL), cliimb was down to about 100 fpm. Still pretty good given that the plane was a little heavy...

 LS

 --------

 LS

 Titan II SS

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John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Sun Mar 15, 2009 7:23 am Post subject: Static rpm - warp drive/912ULS

 	  Quote: 	
		   When I called and talked with Darrell when I ordered my warp drive...   he

 told me that at my altitude he recommended the 68 inch standard tip for my

 912 ul.  So I guess I don't know what difference the taper tip would do 

 for

 me.  Interesting he also mentioned the standard tip was a better choice 

 for

 sea planes.



 Boyd


	




I tested both Warp Drive taper and straight blades on my FS.  At that time I 

was still playing around with aerobatics.  I didn't like the way the Warp 

Drive, either blade, felt, compared to the Jim Culver two blade fixed pitch 

wooden prop.



When I tested the straight blades on the 582 on my mkIII, they did not give 

me the "perceived pitch change" I got with the tapered blades.  The straight 

blades were "straight down the middle" right up to max rpm.  Never flown 

with anything but tapered blades on the 912 engines.



I've flown 70 and 72 inch props on my 912's.  The 72 climbs better and may 

cruise a little better, but is much noisier.  That is why I went back to a 

70 when I changed props last.  It is a little quieter.  I have been playing 

around with going back to a 72 for the Alaska flight.  It gives me a little 

more performance, which might make a difference if I make a mistake and get 

myself into a situation I don't want to be in.  I did this on my first 

flight to Alaska with the 80 horse.  That is why I was so bent on getting a 

100 horse for the next flight to Alaska.  It does make a difference when the 

situation gets tight.



After all the hours with the taper tip blades, it would be interesting to 

see what kind of perception I got with staight blades.



Getting closer to MV every day.  I'm ready!!!



john h

mkIII

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Mar 15, 2009 7:52 am Post subject: Re: Static rpm - warp drive/912ULS

 	  aslsa.rng(at)gmail.com wrote: 	
		  Lucien, When you think about lugging the 912, remember, 1, this is a four stoke engine, much more robust when dealing with prop loading than a 2 stroke, and 2, Rotax designed the 912 series engines to be capable of using constant speed propellers. Just make sure you keep the CHT's below max. A new set of heads is over half the cost of the engine. 



Rick

	




Quite true.... And I tell you what, if I was rich and it was legal for me to do it, I'd go ahead and fit a CS prop. Yeah, it's more complexity, weight etc., but they really make life easy as far as prop loading and etc.



What I try to do on my motor in the meantime is what John suggests, which is to keep it spun up as much as possible. 5400 rpm for takeoff and 5000 minimum at cruise. The sweet spot seems to be about 5080 rpm, or it was with the IVO. If I ever get the weather again, I still need to go out with the WD fitted and see where th sweet spot is.



I had heard in the past about when the flight schools first started using the 912's they weren't used to the higher rpm regimes and were trying to run the motor like the continentals and lycomings lugging them at low RPMs. Apparently, the motors were coming down with major problems well before TBO. 



Once the instructors got trained on the proper rpm's for the 912, all that cleared up and they're going as long as 3000 hours out in the field.



As far as major repairs, truth is it looks to me like something like repairing from an overheating event or etc. would cost in the neighborhood of a new motor. With those parts prices, if I had to do something major I'd probably be better off buying new and not doing whatever broke the thing again .



Fingers crossed that nothing ever happens to this one as I haven't saved up replacement cost yet. Been too busy buying props .



LS

_________________
LS
Titan II SS

Thom Riddle

Joined: 10 Jan 2006
Posts: 1597
Location: Buffalo, NY, USA (9G0)

Posted: Sun Mar 15, 2009 8:03 am Post subject: Re: Static rpm - warp drive/912ULS

Lucien,



Several years ago, I owned a Titan Tornado II (small back seat) with the short 20' wing. It had 912UL and the GSC mechanical in-flight adjustable prop. Great combination. I would set it for about 5600 rpm for take-off and climb at Vy and adjust it to an economical and quiet relatively low rpm full throttle cruise (per Rotax recommended procedure). 



I still have my medical but plan to let it expire this year so I will no longer be able to use a in-flight adjustable prop. That said, a friend (local Titan dealer) had one of his Tornados registered as E-LSA before the deadline WITH the IVO in-flight adjustable prop. The DAR was satisfied with a placard by the prop control that said something to the effect that Sport Pilots must not make any pitch changes during flight.



As we all know, that would not have passed muster in some FSDOs.



do not archive

_________________
Thom Riddle
Buffalo, NY (9G0)

Don't worry about old age... it doesn't last very long.
- Anonymous

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Mar 15, 2009 8:20 am Post subject: Re: Static rpm - warp drive/912ULS

 	  Thom Riddle wrote: 	
		  Lucien,



Several years ago, I owned a Titan Tornado II (small back seat) with the short 20' wing. It had 912UL and the GSC mechanical in-flight adjustable prop. Great combination. I would set it for about 5600 rpm for take-off and climb at Vy and adjust it to an economical and quiet relatively low rpm full throttle cruise (per Rotax recommended procedure). 



I still have my medical but plan to let it expire this year so I will no longer be able to use a in-flight adjustable prop. That said, a friend (local Titan dealer) had one of his Tornados registered as E-LSA before the deadline WITH the IVO in-flight adjustable prop. The DAR was satisfied with a placard by the prop control that said something to the effect that Sport Pilots must not make any pitch changes during flight.



As we all know, that would not have passed muster in some FSDOs.



do not archive 	




Well as I've reported in the past, my medical finally went bye-bye at the ripe old age of 37 and looks like I'll never see it again in this life.  Even if I thought I could get all the squawks covered, I don't dare ever set foot in an AME's office again anyway lest they try to pin me on something else. The FnAA just slap doesn't want me in the air in a big airplane and I"m only too happy to oblige.



Shame that even my complex endorsement that I got years ago in a turbo Arrow couldn't be used under the Sport Pilot rule.... Oh well....

Our group of no-medical folks is continuing to expand, but fortunately our options for flight are still pretty good. So letting it go is by no means the end of one's flying career.



But judging from how my WD performs, I think the "poor mans" CS behavior of it will still cover the speed envelope of our light a/c. The Kolb is in even better shape as it's speed envelope is less wide due to its design and mission. 



Last night I was amazed at how I could go back and forth between 80 and 65mph in a full throttle climb and have the RPM's vary by only about 50 to 60 rpm.  95mph at less than half throttle and 4950 rpm or so was a nice surprise as well.



do not archive



LS

_________________
LS
Titan II SS

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Mar 15, 2009 3:14 pm Post subject: Re: Static rpm - warp drive/912ULS

Maybe this should go to another thread but... The NM Posse to MV potentially increased by 1 today. If ya'll dont mind another titan, the other titan, a II S, on our field may be an additional member. 

I spoke to his owner this morning, as he has it down for its annual and he expressed interest in going to MV.



Guess I better put in for my vacation ASAP....



LS

_________________
LS
Titan II SS

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Sun Mar 15, 2009 5:06 pm Post subject: Re: Static rpm - warp drive/912ULS

Your first flight sounds very promising !  Many of the new LSA airplanes with the 912 S and fixed pitch prop take off very close to 5000 RPM, its very normal for the engine, it just does not develop that last few HP.   Guys that fly Air Cams, including Phil Lockwood I was talking to  one year, cruise the with both the 912-S with less than half power with no problems.  The 912 series has undergone a bunch of changes over the years, many of the early problems don't happen anymore.  I cruise at 4200 RPM and 70 MPH in my Kolb when solo, and around 4300 with my wife, it feels and flys great, using just a bit over 3 GPH.



Mike

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

lucien

Joined: 03 Jun 2007
Posts: 721
Location: santa fe, NM

Posted: Sun Mar 15, 2009 5:57 pm Post subject: Re: Static rpm - warp drive/912ULS

 	  JetPilot wrote: 	
		  Your first flight sounds very promising !  Many of the new LSA airplanes with the 912 S and fixed pitch prop take off very close to 5000 RPM, its very normal for the engine, it just does not develop that last few HP.   Guys that fly Air Cams, including Phil Lockwood I was talking to  one year, cruise the with both the 912-S with less than half power with no problems.  The 912 series has undergone a bunch of changes over the years, many of the early problems don't happen anymore.  I cruise at 4200 RPM and 70 MPH in my Kolb when solo, and around 4300 with my wife, it feels and flys great, using just a bit over 3 GPH.



Mike 	




Well when I had the IVO I at one point had it set to about 5000 to 5100 on climbout (this was when I was experimenting and starting to discover that it was a little overpropped) and it was a pretty anemic climbout of about 500fpm. At 5400, I do almost twice that at nearly 1000fpm. 



So the climb is significantly better for me when spun up. I was doing around 1000fpm with the WD last night also, so the performance there is similar.



I think with the warp drive I'll be able to get away with this or perhaps another 1/2 degree of pitch added back in. I'll just have to see how it does in cruise set the way it is.



Also my speed range really isn't that wide. At this altitude, I hit a wall at 100mph indicated pretty much. I climb at anywhere from 65 to 80 depending on the conditions so top speed is only 20mph away. So I'm hoping I can probably get away with a fairly flat setting, as climb is paramount for me up here in the stratosphere....



And if I can still cruise at 90 to 95 at 5000 rpm I'll be a happy camper as that was what I was doing before with the IVO. But I'm less concerned about that, I happily cruise around at 80 if I have nowhere to go and am just sightseeing.



LS

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LS
Titan II SS

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