Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

Engine Choices

Matronics Email Lists Forum Index -> Kitfox-List

View previous topic :: View next topic

Author Message

msm_9949(at)yahoo.com
Guest

Posted: Sun Jan 13, 2008 10:41 am Post subject: Engine Choices

Ok guys. I've started the spreadsheet. Add to and improve it as you can. 

   

   

Marco Menezes

Model 2 582 N99KX

Engine_choices.xls

Description:

Download

Filename:

Engine_choices.xls

Filesize:

21.5 KB

Downloaded:

408 Time(s)

pwmac(at)sisna.com
Guest

Posted: Sun Jan 13, 2008 11:47 am Post subject: Engine Choices

Hi Marco,

Keep digging. Here are my comments:



A word of caution about the weights. I have been on this list since 

day 1 and I still doubt the weights quoted. For example is the 

coolant included and what about the oil? Then there is the radiator 

and oil cooler. No idea if these things are ever included in engine 

weight. Then every guy has minor differences and may use an aluminum 

vs copper radiator or not even use the recommended oil cooler. Do the 

j guys always use the tiny oil cooler or the hard to install air box? 

Do the guys quoting weight include the engine mount, if so is it the 

heavy or light R912 one?



Probably no a solution to this weight delemia.



Anyway maybe you can add the prop rpm for the two different gear 

boxes for the R912 engines, since one of the advantages of the R912 

is the lower prop speed, thus more efficiency and less noise. Just 

something to keep in mind. I cannot quantify this.



Cruise Hp & fuel burn are the long term things to make you happy. 

Lower initial cost is great for getting started. Reserve power like 

the J3300 has is worthwhile, but the higher fuel burn is the downside 

(not IMO).

Great customer support from multiple service centers and factory is 

unequalled with Rotax. Certainly a real bonus. A personal decision.



LOL, Paul W

======================

At 10:41 AM 1/13/2008, you wrote:

 	  Quote: 	
		  Ok guys. I've started the spreadsheet. Add to and improve it as you can.



Marco Menezes

Model 2 582 N99KX

jdmcbean(at)kitfoxaircraf
Guest

Posted: Sun Jan 13, 2008 12:01 pm Post subject: Engine Choices

Marco,  

            TBO on Jabiru is 2000 bottom and 1000 top…   

TBO on the Rotax is 1500  

<![if !supportEmptyParas]> <![endif]>  

<![if !supportEmptyParas]> <![endif]>  

<![if !supportEmptyParas]> <![endif]>  

 AUTOTEXTLIST \s "E-mail  Signature" <![endif]-->Fly Safe !!  

John & Debra McBean  

208.337.5111  

www.kitfoxaircraft.com    

"It's not how Fast... It's how Fun!"  

<![endif]--><![if !supportEmptyParas]> <![endif]>  

-----Original Message-----

 From: owner-kitfox-list-server(at)matronics.com [mailto:owner-kitfox-list-server(at)matronics.com]On Behalf Of Marco Menezes

 Sent: Sunday, January 13, 2008 11:41 AM

 To: Matronics.com

 Subject: Engine Choices  

<![if !supportEmptyParas]> <![endif]>  

Ok guys. I've started the spreadsheet. Add to and improve it as you can.   

   

   



 

 Marco Menezes

 Model 2 582 N99KX  

   

       [quote][b]

av8rps

Joined: 05 Jan 2008
Posts: 33
Location: Central Wisconsin

Posted: Sun Jan 13, 2008 2:20 pm Post subject: Re: Engine Choices

(Marco says "Ok guys. I've started the spreadsheet. Add to and improve it as you can...") 

   

Marco,



One thing that I would suggest changing is the column heading words for column E.  The current "Pwr & Wght" should be changed to "Hp per LB".  Just words I know, but I think it better exemplifies which engine is producing the most power per lb, the thing that is probably the single most important thing to consider when comparing engines, (aside from actual prop thrust - which as of right now we don't have a good way to know).



The fuel burn for the 912 I know is not right.  I'll pull my manuals next time I'm at the airport so we can fix that.  It also would be nice to add the 914 Rotax, as that is hands down Rotaxes real power house.



Nice Job!  Very nice spreadsheet for those deciding on an engine.



Paul Seehafer

_________________
Model IV-1200 912ul Amphib
Avid Flyer Sn#1 and Sn#26
Highlander 912s taildragger
Lake Amphibian
Central Wisconsin
paul676@tds.net

av8rps

Joined: 05 Jan 2008
Posts: 33
Location: Central Wisconsin

Posted: Sun Jan 13, 2008 2:34 pm Post subject: Re: Engine Choices

(Paul W says "A word of caution about the weights. I have been on this list since day 1 and I still doubt the weights quoted. For example is the 

coolant included and what about the...") 



Paul,



I too don't agree with how the weights come out for all the engines as the mfrs have stated them.  In another topic area I just asked Lynn Matteson to compare his Jabiru 2200 powered Model IV against my 912ul powered Model IV for empty weights and options, as I seem to recall our airplanes are similar weights.  And if that's true, considering all the options I have on my airplane (its far from a light one), the Jabiru is really no lighter by the time it is installed.  



The same seems to be true of the aircraft engines as well, with the mfrs stating weights that are a bit deceiving.    

So the true test is for a bunch of us to post our empty weights for our various powered Kitfoxes, and then to give details as to what options and models they are so those making engine choices can make an educated decision based on facts.  Or at least averages.



What do you think?  



Hey Marco!  Are you interested in setting up a spreadsheet for that? 



Paul Seehafer

_________________
Model IV-1200 912ul Amphib
Avid Flyer Sn#1 and Sn#26
Highlander 912s taildragger
Lake Amphibian
Central Wisconsin
paul676@tds.net

pwmac(at)sisna.com
Guest

Posted: Sun Jan 13, 2008 3:20 pm Post subject: Engine Choices

The best weight data will come from a guy that does a swap and then 

weighs the plane before & after.

  However the KFs seem to fly fine with all the choices, so maybe the 

numbers are not as important as we all make them??? Perfection is 

hard to achieve. But it would be nice to get close.

I remember in the old days when Murle W did a R912 swap to sube and 

gave us real data.

Paul W

============

At 02:34 PM 1/13/2008, you wrote:

 	  Quote: 	
		  



(Paul W says "A word of caution about the weights. I have been on 

this list since day 1 and I still doubt the weights quoted. For example is the

coolant included and what about the...")



Paul,



I too don't agree with how the weights come out for all the engines 

as the mfrs have stated them.  In another topic area I just asked 

Lynn Matteson to compare his Jabiru 2200 powered Model IV against my 

912ul powered Model IV for empty weights and options, as I seem to 

recall our airplanes are similar weights.  And if that's true, 

considering all the options I have on my airplane (its far from a 

light one), the Jabiru is really no lighter by the time it is installed.



The same seems to be true of the aircraft engines as well, with the 

mfrs stating weights that are a bit deceiving.

So the true test is for a bunch of us to post our empty weights for 

our various powered Kitfoxes, and then to give details as to what 

options and models they are so those making engine choices can make 

an educated decision based on facts.  Or at least averages.



What do you think?



Hey Marco!  Are you interested in setting up a spreadsheet for that? 



Paul Seehafer



--------

Model IV-1200 912ul Amphib

Avid Flyer

Lake Amphibian

Central Wisconsin

paul676(at)tds.net





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=157866#157866

Lynn Matteson

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

Posted: Sun Jan 13, 2008 3:31 pm Post subject: Engine Choices

At the risk of becoming annoying (I know, I've already passed that  

milestone), forget the airplanes! Weigh the freakin' engines!



Lynn Matteson

Grass Lake, Michigan

Kitfox IV Speedster  w/Jabiru 2200

flying w/460+ hrs



On Jan 13, 2008, at 6:19 PM, paul wilson wrote:



 	  Quote: 	
		   



 The best weight data will come from a guy that does a swap and then  

 weighs the plane before & after.

  However the KFs seem to fly fine with all the choices, so maybe  

 the numbers are not as important as we all make them??? Perfection  

 is hard to achieve. But it would be nice to get close.

 I remember in the old days when Murle W did a R912 swap to sube and  

 gave us real data.

 Paul W

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Lynn Matteson

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

Posted: Sun Jan 13, 2008 3:32 pm Post subject: Engine Choices

I'l repeat here what I said on another post..paraphrased...you can't  

compare one empty Kitfox with another and blame the difference on the  

engine. If you're going to compare weights, compare weights, not  

calculated weights based on equipment, paint jobs, etc. No jury would  

buy that argument. We need to get that anal bunch from NASCAR to send  

some of their boys over to settle this one, I'm afraid.

Lynn Matteson

Grass Lake, Michigan

Kitfox IV Speedster  w/Jabiru 2200

flying w/460+ hrs

On Jan 13, 2008, at 5:34 PM, av8rps wrote:



 	  Quote: 	
		   



 (Paul W says "A word of caution about the weights. I have been on  

 this list since day 1 and I still doubt the weights quoted. For  

 example is the

 coolant included and what about the...")



 Paul,



 I too don't agree with how the weights come out for all the engines  

 as the mfrs have stated them.  In another topic area I just asked  

 Lynn Matteson to compare his Jabiru 2200 powered Model IV against  

 my 912ul powered Model IV for empty weights and options, as I seem  

 to recall our airplanes are similar weights.  And if that's true,  

 considering all the options I have on my airplane (its far from a  

 light one), the Jabiru is really no lighter by the time it is  

 installed.



 The same seems to be true of the aircraft engines as well, with the  

 mfrs stating weights that are a bit deceiving.

 So the true test is for a bunch of us to post our empty weights for  

 our various powered Kitfoxes, and then to give details as to what  

 options and models they are so those making engine choices can make  

 an educated decision based on facts.  Or at least averages.



 What do you think?



 Hey Marco!  Are you interested in setting up a spreadsheet for  

 that? 



 Paul Seehafer



 --------

 Model IV-1200 912ul Amphib

 Avid Flyer

 Lake Amphibian

 Central Wisconsin

 paul676(at)tds.net





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=157866#157866

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

msm_9949(at)yahoo.com
Guest

Posted: Sun Jan 13, 2008 8:58 pm Post subject: Engine Choices

The data I've included is derived from supplier and manufacturer websites. (Sources are included as "comments"). But if anybody wants to correct or supplement based on their experience, or add still more engine options, great!  Please have at it.

   

  Hey . . . my plan was just to get the ball rolling. I'm not gonna do all the work. 



av8rps <paul676(at)tds.net> wrote:

  [quote]--> Kitfox-List message posted by: "av8rps" 



(Marco says "Ok guys. I've started the spreadsheet. Add to and improve it as you can...") 



Marco,



One thing that I would suggest changing is the column heading words for column E. The current "Pwr & Wght" should be changed to "Hp per LB". Just words I know, but I think it better exemplifies which engine is producing       Be a better friend, newshound, and  [quote][b]

msm_9949(at)yahoo.com
Guest

Posted: Sun Jan 13, 2008 9:00 pm Post subject: Engine Choices

Like I said Paul, if you think that would be useful, please have at it! Just add a few columns and fill them in.



av8rps <paul676(at)tds.net> wrote:  [quote]--> Kitfox-List message posted by: "av8rps" 



(Paul W says "A word of caution about the weights. I have been on this list since day 1 and I still doubt the weights quoted. For example is the 

coolant included and what about the...") 



Paul,



I too don't agree with how the weights come out for all the engines as the mfrs have stated them. In another topic area I just asked Lynn Matteson to compare his Jabiru 2200 powered Model IV against my 912ul powered Model IV for empty weights and options, as I seem to recall our airplanes are similar weights. And if that's true, considering all the options I have on my airplane (its far from a light one), the Jabiru is really      [quote][b]

av8rps

Joined: 05 Jan 2008
Posts: 33
Location: Central Wisconsin

Posted: Mon Jan 14, 2008 5:35 am Post subject: Re: Engine Choices

(Lynn Matteson says "At the risk of becoming annoying (I know, I've already passed that milestone), forget the airplanes! Weigh the freakin' engines!")



Lynn,



Don't get me wrong.  I agree that weighing the complete and flyable engine packages would be best.  But that would be quite an undertaking, not probable to happen anytime soon.  Plus, as you said earlier it would be difficult to make certain it was done without having someones thumb on the scale, so to speak. 



So my idea of using averages for various engines and models with options and equipment was just to provide those in question with that, an average they could expect if they built or bought one similar to the ones owners listed.  



As an example; With as many 912 powered Kitfoxes out there, and all the information that has been shared here on the list, it has become pretty easy to come up with an average for a 912 model IV.  Plain and simple, a 912 model IV as an average will run between 625 and 675 lbs.  Light ones will be in the low 600's, and heavy ones in the 700 lb range.  It's really as simple as that.  I don't know about you, but if I was building and considering using a 912 that would be helpful information for me. 



 And if I were torn between the Jab and the 912, and I also knew the average for a Jabiru powered Model IV was in the same empty weight range, I'd probably start asking owners for performance numbers, once again trying to come up with an average of what I could expect.  



Now if a builder really wanted to get scientific beyond this list of averages, having exact engine flying weights would be great.  From that they could determine horsepower per pound numbers, which is really all that is important (unless the weight is just more than his airframe was designed for).  But better yet, prop thrust per pound is the number I'd be looking for.  And I'd make sure the prop used in the thrust test was appropriate to the airframe I was going to install the engine on (E.g.; prop that works good on a Sonex probably isn't the best prop for a Kitfox).  So once again, I agree with your idea that it would be best to have accurate engine info in front of anyone trying to make a decision about engine choice.  Unfortunately, all that information isn't available unless some great writer we know (big smile) takes on that arduous task.    



But we do have Kitfoxes that are flying with a variety of engines, and options right now.  So we have the ability to come up with good averages for empty weights, as well as performance.  So the guy that just wants to keep building so he can get in the air as soon as possible can do so.  He doesn't have to spend hours pouring over information, hoping what he thought was correct information works out like he planned.  We already have gained the experience with our Kitfoxes, and have proven results.  That can save builders a lot of time, and money most likely, while also providing them with an engine decision they will be happy with.  



And for what it's worth, this is good banter for this list.  While we might be boring some readers to death, or appear to be arguing the Jab vs the 912, I'm certain what has been discussed here has already been helping some to better make an engine decision.  



Paul Seehafer

_________________
Model IV-1200 912ul Amphib
Avid Flyer Sn#1 and Sn#26
Highlander 912s taildragger
Lake Amphibian
Central Wisconsin
paul676@tds.net

propellerdesign(at)tele2.
Guest

Posted: Mon Jan 14, 2008 6:19 am Post subject: Engine Choices

This might be the future:



http://ppdgemini.com/_PDF/Gemini100_Spec_Sheet.pdf



Jan

---

Lynn Matteson

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

Posted: Mon Jan 14, 2008 6:47 am Post subject: Engine Choices

Ok, Paul, I see your point. I just saw the task of comparing the  

various components that we install, paint on, or otherwise stuff into  

our planes as a pretty daunting job, and thought that  weighing the  

engine would be the simple way to do it.

I gotta admit, though, that when I started to think about building a  

plane, cost was a pretty big factor. I had just retired, and knew how  

much money I was going to have to play with, and figured I could buy  

the plane outright, bring it home, and start (continue) to build it,  

and as the monthly pension checks came in, start to decide how many  

bean dinners could be substituted for steaks, and then decide on an  

engine. Performance figures didn't enter my mind. During this time, I  

found a 3-part Kitplanes magazine article that told of one builder's  

story, and that's what helped me make a decision.

I'm pretty much a shade-tree mechanic, so this decision process was  

in keeping with my level of thinking, and my way of life. Others will  

take a different path to the decision-making process, I'm sure, armed  

with the information from this list.

Keep up the good work.



Lynn Matteson

Grass Lake, Michigan

Kitfox IV Speedster  w/Jabiru 2200

flying w/460+ hrs



On Jan 14, 2008, at 8:35 AM, av8rps wrote:



 	  Quote: 	
		   



 (Lynn Matteson says "At the risk of becoming annoying (I know, I've  

 already passed that milestone), forget the airplanes! Weigh the  

 freakin' engines!")



 Lynn,



 Don't get me wrong.  I agree that weighing the complete and flyable  

 engine packages would be best.  But that would be quite an  

 undertaking, not probable to happen anytime soon.  Plus, as you  

 said earlier it would be difficult to make certain it was done  

 without having someones thumb on the scale, so to speak.



 So my idea of using averages for various engines and models with  

 options and equipment was just to provide those in question with  

 that, an average they could expect if they built or bought one  

 similar to the ones owners listed.



 As an example; With as many 912 powered Kitfoxes out there, and all  

 the information that has been shared here on the list, it has  

 become pretty easy to come up with an average for a 912 model IV.   

 Plain and simple, a 912 model IV as an average will run between 625  

 and 675 lbs.  Light ones will be in the low 600's, and heavy ones  

 in the 700 lb range.  It's really as simple as that.  I don't know  

 about you, but if I was building and considering using a 912 that  

 would be helpful information for me.



  And if I were torn between the Jab and the 912, and I also knew  

 the average for a Jabiru powered Model IV was in the same empty  

 weight range, I'd probably start asking owners for performance  

 numbers, once again trying to come up with an average of what I  

 could expect.



 Now if a builder really wanted to get scientific beyond this list  

 of averages, having exact engine flying weights would be great.   

 From that they could determine horsepower per pound numbers, which  

 is really all that is important (unless the weight is just more  

 than his airframe was designed for).  But better yet, prop thrust  

 per pound is the number I'd be looking for.  And I'd make sure the  

 prop used in the thrust test was appropriate to the airframe I was  

 going to install the engine on (E.g.; prop that works good on a  

 Sonex probably isn't the best prop for a Kitfox).  So once again, I  

 agree with your idea that it would be best to have accurate engine  

 info in front of anyone trying to make a decision about engine  

 choice.  Unfortunately, all that information isn't available unless  

 some great writer we know (big smile) takes on that arduous task.



 But we do have Kitfoxes that are flying with a variety of engines,  

 and options right now.  So we have the ability to come up with good  

 averages for empty weights, as well as performance.  So the guy  

 that just wants to keep building so he can get in the air as soon  

 as possible can do so.  He doesn't have to spend hours pouring over  

 information, hoping what he thought was correct information works  

 out like he planned.  We already have gained the experience with  

 our Kitfoxes, and have proven results.  That can save builders a  

 lot of time, and money most likely, while also providing them with  

 an engine decision they will be happy with.



 And for what it's worth, this is good banter for this list.  While  

 we might be boring some readers to death, or appear to be arguing  

 the Jab vs the 912, I'm certain what has been discussed here has  

 already been helping some to better make an engine decision.



 Paul Seehafer



 --------

 Model IV-1200 912ul Amphib

 Avid Flyer

 Lake Amphibian

 Central Wisconsin

 paul676(at)tds.net





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=157951#157951

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Mon Jan 14, 2008 8:50 am Post subject: Engine Choices

At 05:35 AM 1/14/2008, you wrote:

 	  Quote: 	
		  We already have gained the experience with our Kitfoxes, and have 

proven results.


	


         Actually I believe you already have the results. Because of 

the relatively large numbers there is a sort of "natural selection" 

process at work in the Kitfox community. If you were to simply add 

the numbers of engines of each type in each airframe you would see 

the relative "value" of each engine, including all factors. Though it 

would seem that new engines would be under-represented, that 

under-representation reflects their relatively "unproven" status. As 

engines become "proven" they take over the market, as the 912 did 

from the 582, and as the Jabiru is presently doing to the Subaru and 

VW. (No offense intended. Remember I fly a 582.)

Guy Buchanan

San Diego, CA

K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

Lynn Matteson

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

Posted: Mon Jan 14, 2008 9:41 am Post subject: Engine Choices

Just a reminder of one example of the "natural selection" process at  

work:

Recall that Beta came out with a superior tape recording process,  

quality-wise, but wasn't able to pack enough tape into the cassette  

so that bored housewives could go on vacation for three weeks and  

record their favorite soaps each day. VHS won the battle by offering  

such a tape at a much lower resolution, thus giving the public what  

they wanted. These people were satisfied with mundane quality if it  

meant getting their soaps recorded. VHS finally put Beta out of  

business, because of sheer numbers, not quality.

(There was a sign that hung in my old workplace that said: "Give the  

customer quality, whether they want it or not")



This is by no means a reflection (so far anyway) on the homebuilt  

industry, just something to keep in mind when looking at the  

"numbers"....remember, if you torture numbers enough, they will tell  

you anything.  : )



Lynn Matteson

Grass Lake, Michigan

Kitfox IV Speedster  w/Jabiru 2200

flying w/460+ hrs

On Jan 14, 2008, at 11:36 AM, Guy Buchanan wrote:



 	  Quote: 	
		   



 At 05:35 AM 1/14/2008, you wrote:

> We already have gained the experience with our Kitfoxes, and have  

> proven results.



         Actually I believe you already have the results. Because of  

 the relatively large numbers there is a sort of "natural selection"  

 process at work in the Kitfox community. If you were to simply add  

 the numbers of engines of each type in each airframe you would see  

 the relative "value" of each engine, including all factors. Though  

 it would seem that new engines would be under-represented, that  

 under-representation reflects their relatively "unproven" status.  

 As engines become "proven" they take over the market, as the 912  

 did from the 582, and as the Jabiru is presently doing to the  

 Subaru and VW. (No offense intended. Remember I fly a 582.)

 Guy Buchanan

 San Diego, CA

 K-IV 1200 / 582-C / Warp / 100% done, thanks mostly to Bob Ducar.

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

Michel

Joined: 10 Jan 2006
Posts: 966
Location: Norway

Posted: Mon Jan 14, 2008 11:52 am Post subject: Engine Choices

Since we are comparing engines, here is from my annual weight and 

balances:

Kitfox 3, pretty much 'vanilla taste' with original tube gear, etc. and 

Rotax 582: Empty weight: 236 kg. (520 lbs)

The same but with Jabiru 2200: 241 kg. (531 lbs)

That is only 11 lbs more. But the Jabiru, with 4 cylinders, has a own 

CoG that is more forward that the 582. Still, moving the battery from 

firewall to behind the seat was all it took to keep the same CoG for 

the plane.



Cheers,

Michel Verheughe

Norway

Kitfox 3 - Jabiru 2200 ... (hum, why do I have a deja-vu?

_________________
Kitfox 3 - Jabiru 2200

Display posts from previous:

	Matronics Email Lists Forum Index -> Kitfox-List	All times are GMT - 8 Hours
Page 1 of 1

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum