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pulsar xp with subaru ea81 ?

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ar99kid

Joined: 10 Nov 2013
Posts: 5
Location: Romania

Posted: Sun Nov 10, 2013 9:58 pm Post subject: pulsar xp with subaru ea81 ?

hello 

i am a new owner of a pulsar XP project . the aircraft is almost finished as body , but without an engine. i have sourced here a subaru ea 81 motor with bing carbs and reductor at 200lbs. this motor installed with all the fluids will be about 230-240 lbs. xp suppose to heave a rotax 912 and this one is 60-70lbs lighter. 



so question : is this motor too heavy for the pulsar xp ? i was thinking to get the CG back in place positioning the battery farther back and maybe some of the accessories . also considering to make the engine mounting something like that for jabiru2200 on the firewall . working in composites is not a problem for me  but i would like to learn some opinions about this setup .

i have the composites wing spars and covering , not the wood ones !



thanks !

briana(at)xtra.co.nz
Guest

Posted: Sun Nov 10, 2013 10:28 pm Post subject: pulsar xp with subaru ea81 ?

Not only is the engine way too heavy, you probably wouldn’t find enough room to fit it, plus the reduction gear into the cowling.



Brian



On 11/11/2013, at 6:58 pm, ar99kid <ar99kid(at)gmail.com> wrote:



 	  Quote: 	
		   

 

 hello 

 i am a new owner of a pulsar XP project . the aircraft is almost finished as body , but without an engine. i have sourced here a subaru ea 81 motor with bing carbs and reductor at 200lbs. this motor installed with all the fluids will be about 230-240 lbs. xp suppose to heave a rotax 912 and this one is 60-70lbs lighter. 

 

 so question : is this motor too heavy for the pulsar xp ? i was thinking to get the CG back in place positioning the battery farther back and maybe some of the accessories . also considering to make the engine mounting something like that for jabiru2200 on the firewall . working in composites is not a problem for me  but i would like to learn some opinions about this setup .

 i have the composites wing spars and covering , not the wood ones !

 

 thanks !

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=412672#412672

ar99kid

Joined: 10 Nov 2013
Posts: 5
Location: Romania

Posted: Sun Nov 10, 2013 10:40 pm Post subject: Re: pulsar xp with subaru ea81 ?

thanks for quick answer ! 



the engine space is doable ! i have taken all measurements and with some mods to the lower cowl for oil pan and radiator is working . so this is ok ! 



the weight is my concern because i have never flight a pulsar so i really do't know this small aircraft... still i saw there are also fitted with the rotax 914 which is 30lbs heavier than 912  so remains "only"  about 30lbs difference ! 



is this such a big problem ?

kdpalmer(at)mweb.co.za
Guest

Posted: Sun Nov 10, 2013 11:13 pm Post subject: pulsar xp with subaru ea81 ?

The 914 is not for the Pulsar XP - only Pulsar II & III with structual 

fuselage modifications with AUTW of 1200lb



K'd

---

briana(at)xtra.co.nz
Guest

Posted: Sun Nov 10, 2013 11:16 pm Post subject: pulsar xp with subaru ea81 ?

In the XP version the Rotax engine is mounted on a bed mount in the lower cowling. The loads are carried on uniglass beams glassed into the lower cowling, and then through the firewall back into the fuselage. Later versions, I think the series II and III, were built differently, with the firewall becoming more of a structural component, and the loads from the truss type engine mount being carried through into the fuselage with a completely different system. There have been some of the later series fitted with the Rotax 914, and I think that there may also have been an increase in the maximum weight too.



If you have to modify the engine mounting arrangements to handle the loads of a heavier engine, then you are really beginning to design a new aeroplane. Heavier loads, more structure, more weight.



The MAUW is another consideration. If you are adding 60 - 70 lbs of engine, then that is 60 - 70 lbs less fuel you can carry. That is equivalent to about 40 litres of fuel. That only leaves about 30 litres [max] to play with. What is the fuel consumption of the Subaru ?



Also, the most common location for the battery in the XP is already behind the seats. You can’t get access any further back. Then you add more weight with heavier and longer battery cables. It’s a no win situation.



Why try to reinvent something when there is a proven formula that works really well. The Pulsar operates brilliantly with the Rotax 912. With the standard 80hp version I can exceed VNE in level flight, and my average fuel consumption is about 13 litres/hr.



Brian

On 11/11/2013, at 7:40 pm, ar99kid <ar99kid(at)gmail.com> wrote:



 	  Quote: 	
		   

 

 thanks for quick answer ! 

 

 the engine space is doable ! i have taken all measurements and with some mods to the lower cowl for oil pan and radiator is working . so this is ok ! 

 

 the weight is my concern because i have never flight a pulsar so i really do't know this small aircraft... still i saw there are also fitted with the rotax 914 which is 30lbs heavier than 912  so remains "only"  about 30lbs difference ! 

 

 is this such a big problem ?

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=412674#412674

freedom4life(at)xtra.co.n
Guest

Posted: Sun Nov 10, 2013 11:23 pm Post subject: pulsar xp with subaru ea81 ?

The EA81 engine does not produce near enough horsepower for its weight.  I 

wouldn't expect you would get any more than 65 - 70 usable horsepower from 

this engine. I have flown several aircraft with this engine and the same 

aircraft with the Rotax 912 have over double the climb rate and 20% more top 

speed.  I really think you will spoil an otherwise fantastic aircraft and 

you will disappointed with the result.



Cliff




thanks for quick answer !



the engine space is doable ! i have taken all measurements and with some 

mods to the lower cowl for oil pan and radiator is working . so this is ok !



the weight is my concern because i have never flight a pulsar so i really 

do't know this small aircraft... still i saw there are also fitted with the 

rotax 914 which is 30lbs heavier than 912  so remains "only"  about 30lbs 

difference !



is this such a big problem ?





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=412674#412674

ar99kid

Joined: 10 Nov 2013
Posts: 5
Location: Romania

Posted: Sun Nov 10, 2013 11:46 pm Post subject: Re: pulsar xp with subaru ea81 ?

well i get your points ! 



the main reason i am trying to do this setup is the price/budget. subaru or vw is waaay accessible than a 912 ...they say that this ea81 is 100hp rated also with 10-15% lower consumption than 912 . but because i have access to this engine i will weight it and come back with real numbers and start from there ...



thank you all for your inputs !

kulpa(at)att.net
Guest

Posted: Mon Nov 11, 2013 10:26 am Post subject: pulsar xp with subaru ea81 ?

When I was initially looking at the Pulsar I talked to Mark Brown about 

the Subaru engine.  He was very adamant that this engine was not 

appropriate for the Pulsar, even the series III. I suggest you forget 

the Subaru and find a 912 or Jabiru 2200.



Best Regards, Bill



On 11/11/2013 1:46 AM, ar99kid wrote:

 	  Quote: 	
		   



 well i get your points !



 the main reason i am trying to do this setup is the price/budget. subaru or vw is waaay accessible than a 912 ...they say that this ea81 is 100hp rated also with 10-15% lower consumption than 912 . but because i have access to this engine i will weight it and come back with real numbers and start from there ...



 thank you all for your inputs !





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=412678#412678

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Mon Nov 11, 2013 12:04 pm Post subject: pulsar xp with subaru ea81 ?

Trying to save money by overloading the airframe will get you in trouble,  big time. I have pictures of airframe failures because the cheap engine was too  heavy, and they are not pretty. You can expect to see the fuselage split just  ahead of the wing fillet. This is not just a small crack, we are talking about  the whole front of the plane falling off. Lucky for the Pulsar builder/pilot,  the airframe failed in landing and he was slow enough he did not get hurt, but  the plane is totaled. 

  

 The Pulsar was redesigned for each engine it uses. The fuselage was  reinforced, in the molds, to accommodate the engine weights and power. The  tail section was beefed up with different materials being used. You cannot  duplicate this process in your shop.

  

 You are attempting to install an engine that is heavier than the heaviest  engine ever designed for the Pulsar. If you do this you should do significant  load testing, on the ground, to assure the structure will not come apart on a  windy day, at altitude. You are risking a lot for a small savings, on a kit you  did not build. For your own safety, please reconsider, install a Rotax and enjoy  the aircraft. If you want to use the Subaru, buy an unfinished RV, there are a  few unhappy owners flying RVs with the Subaru. 

  

 If you decide to ignore our advice, please do all of us a favor and when  you register the aircraft, do not call it a Pulsar. It truly will not be a  Pulsar, it will be a one off design.

  

 I know this sounds a little harsh, but we are starting to see these  unfinished kits going through several owners, and who knows what is being done  by each, and then someone wants to do things that far exceed the design strength  of the aircraft. It is not safe, there are just too many things to consider to  make changes to the design.

  

 Greg Smith

 1500 hours flying Pulsar

  

  In a message dated 11/11/2013 1:48:57 A.M. Central Standard Time,  ar99kid(at)gmail.com writes:

  	  Quote: 	
		  -->    Pulsar-List message posted by: "ar99kid" <ar99kid(at)gmail.com>



well    i get your points ! 



the main reason i am trying to do this setup is    the price/budget. subaru or vw is waaay accessible than a 912 ...they say that    this ea81 is 100hp rated also with 10-15% lower consumption than 912 . but    because i have access to this engine i will weight it and come back with real    numbers and start from there ...



thank you all for your inputs    !





Read this topic online    here:



http://forums.matronics.com/viewtopic.php?p=412678#412678

	


 [quote][b]

mbrowntx3(at)juno.com
Guest

Posted: Mon Nov 11, 2013 1:01 pm Post subject: pulsar xp with subaru ea81 ?

Well said.  You may save another life or at least at lot of grief.

 

 

 

--------

ar99kid

Joined: 10 Nov 2013
Posts: 5
Location: Romania

Posted: Tue Nov 12, 2013 1:52 am Post subject: Re: pulsar xp with subaru ea81 ?

thanks for answers ! i am not considering any advise as being harsh because that's way i have asked here ...anyway in this moment i didn't take any direction just gathering information and opinions. so as i have said yesterday i went last evening to the engine and weighted it  here it is :



engine + carbs , starter , oil , alternator = 75kg 

flywheel , rotax C drive , adapter plate , exhaust 15kg



so total engine is 90 kg plus 5-6 kg water and radiator , grand total 95kg 



with the mechanic together we have aproximated the following :

912 motor : 58kg empty + 6kg oil and oil tank +5kg water and radiator +4kg exhaust . grand total 73 kg 



now the real difference is 22 kg 50lbs ! both engines full with water and oil only without props ...



how is this looking  ?



with some reinforcement to the bed and maybe to the firewall and making also a a cradle to mount the engine on the bed and to the firewall ... a mixed mounting.



ground test ... is it ok to put 400kg weight instead of the engine to test the structure holding ?



thanks

kdpalmer(at)mweb.co.za
Guest

Posted: Tue Nov 12, 2013 2:39 am Post subject: pulsar xp with subaru ea81 ?

This group is basically an Amature kit builders Forum - nobody is qualified 

to commit themselves to questions like this, I suggest you employ an 

Aeronautical engineer, and don't call it a Pulsar try "Kid's Toy"



K'd



---

kymc(at)internode.on.net
Guest

Posted: Tue Nov 12, 2013 2:41 am Post subject: pulsar xp with subaru ea81 ?

To be honest with you I would not consider the Subaru engine just on the weight alone besides the issues with actually getting it to fit and getting the cooling to work. To have any fuel to fly with you would in effect be building a single seat aircraft to stay within max weight. 



22 kg extra in this small aircraft is a LOT and to get any way close to weight and balance you would be adding weight back in the aircraft in addition to the battery further reducing the payload to stay within max weight. You would also be adding weight to the aircraft with additional material to reinforce the firewall area. You also need to consider if you can keep the engine no further forward otherwise that just makes the weight issue worse.



I had a Pulsar SP100 and after a write off accident and being sold by the insurance company it was rebuild with a Subaru engine by the new owner. On the test flight it was almost uncontrollable and was porpoising after it left the ground and after a few hundred metres crashed. Fortunately it only got to a few feet off the ground so the pilot walked away - and no it was not me as I had nothing to do with rebuild.



While it may seem like an inexpensive way to power an aircraft it is fraught with danger and how much is really needed to be reinforced to make it strong enough. You will be putting quite a lot of load on various parts of the airframe including the area of the fuselage directly behind the wings. In the end you are likely to end up with an aircraft that is outside of the design parameters with potential structural loads that could cause failure and a crash.



Look around for a used Rotax 912 engine with some hours to run and go that way. It will be a lot safer and the aircraft will have a resale value.



be safe



Kym

Australia  

RV6A



On 12/11/2013, at 8:22 PM, ar99kid wrote:



 	  Quote: 	
		   

 

 thanks for answers ! i am not considering any advise as being harsh because that's way i have asked here ...anyway in this moment i didn't take any direction just gathering information and opinions. so as i have said yesterday i went last evening to the engine and weighted it  here it is :

 

 engine + carbs , starter , oil , alternator = 75kg 

 flywheel , rotax C drive , adapter plate , exhaust 15kg

 

 so total engine is 90 kg plus 5-6 kg water and radiator , grand total 95kg 

 

 with the mechanic together we have aproximated the following :

 912 motor : 58kg empty + 6kg oil and oil tank +5kg water and radiator +4kg exhaust . grand total 73 kg 

 

 now the real difference is 22 kg 50lbs ! both engines full with water and oil only without props ...

 

 how is this looking  ?

 

 with some reinforcement to the bed and maybe to the firewall and making also a a cradle to mount the engine on the bed and to the firewall ... a mixed mounting.

 

 ground test ... is it ok to put 400kg weight instead of the engine to test the structure holding ?

 

 thanks

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=412871#412871

kdpalmer(at)mweb.co.za
Guest

Posted: Tue Nov 12, 2013 3:09 am Post subject: pulsar xp with subaru ea81 ?

Kym,

         To add to this the SP100 was also built to take a heavier engine, I 

don't know the SP's MAUW. must be 1200lb plus ?



K'd



---

kdpalmer(at)mweb.co.za
Guest

Posted: Tue Nov 12, 2013 3:51 am Post subject: pulsar xp with subaru ea81 ?

Kym,

         I should have also mentioned a 'maiden' flight by a great friend 

Dave Lentle approved test pilot and Com on 737's, done in a Dragonfly with a 

Subaru engine. Crashed after 50km with major engine problems and oil all 

over the canopy, crash landed because of visibility.

Read his book on a near death experience and years of recovery before being 

certified to fly again.

"Lift your Life" 'A true story to inspire and encourage' by Dave Lentle. 

ISBN 9780620519359  or eISBN 9780620549417

Learn a point or two on how life can kick you in the teeth when helping a 

friend.



Regards

Keith

---

gregsmi

Joined: 01 Jan 2011
Posts: 268
Location: Topeka, KS

Posted: Tue Nov 12, 2013 6:06 am Post subject: pulsar xp with subaru ea81 ?

You are only looking at beefing up the forward part of the fuselage, You  missed the part of my explanation about the tail changes that were made for each  engine change in the Pulsar design. You would have to increase the size of the  tail surfaces and also strengthen the tail area. 

  

 This is just too crazy to attempt. It is obvious it will not be safe and  could lead to tragic consequences. At this point you should find  yourself a good aircraft design engineer, preferably one that works daily with  structural load calculations and is familiar with composites, Pay him  for his time, and it will take some time, for him to go through the Pulsar  design and figure out what it will take to fly the aircraft with that engine.  

  

 If he takes the assignment and spends more than four hours on it,  you can tell him to stop, you will not be able to afford his time,  will not be able to accomplish the recommended design changes, and if by chance  the two of you come up with everything that needs to be done and actually get it  done, you will have invested a huge some of money in development. The aircraft  will have new wings, new fuselage, new tail, new landing gear, but you may  be able to save the canopy. It will weigh a lot more than the Pulsar and with  that engine, will have terrible performance.

  

 I have seen 700 hour 912 engines for $6,500. If you want to finish this  kit, you should be shopping for a 912 engine. Get rid of the Subaru idea, it  will cost you dearly.

  

 Greg

  

  

  

  

  

  In a message dated 11/12/2013 3:56:16 A.M. Central Standard Time,  ar99kid(at)gmail.com writes:

  	  Quote: 	
		  -->    Pulsar-List message posted by: "ar99kid"    <ar99kid(at)gmail.com>



thanks for answers ! i am not considering any    advise as being harsh because that's way i have asked here ...anyway in this    moment i didn't take any direction just gathering information and opinions. so    as i have said yesterday i went last evening to the engine and weighted    it  here it is :



engine + carbs , starter , oil , alternator =    75kg 

flywheel , rotax C drive , adapter plate , exhaust 15kg



so    total engine is 90 kg plus 5-6 kg water and radiator , grand total 95kg    



with the mechanic together we have aproximated the following :

912    motor : 58kg empty + 6kg oil and oil tank +5kg water and radiator +4kg exhaust    . grand total 73 kg 



now the real difference is 22 kg 50lbs ! both    engines full with water and oil only without props ...



how is this    looking  ?



with some reinforcement to the bed and maybe to the    firewall and making also a a cradle to mount the engine on the bed and to the    firewall ... a mixed mounting.



ground test ... is it ok to put 400kg    weight instead of the engine to test the structure holding    ?



thanks





Read this topic online    here:



http://forums.matronics.com/viewtopic.php?p=412871#412871

	


 [quote][b]

ar99kid

Joined: 10 Nov 2013
Posts: 5
Location: Romania

Posted: Tue Nov 12, 2013 6:43 am Post subject: Re: pulsar xp with subaru ea81 ?

well seems that this engine is a REALLY  heavy problem ! i will reconsider my options ...from all your inputs here , this is a no no situation . i was hoping that this body will be stronger and can handle some margin in engine weight . 

still 6500 usd which will get here with shipping and all taxes like 9000usd is too much ! jabiru , maybe vw ...something to get  70-80hp and still be in the 75 kg limit 



thanks for your help !

paqs345(at)gmail.com
Guest

Posted: Tue Nov 12, 2013 7:53 am Post subject: pulsar xp with subaru ea81 ?

After reading all this,  I can confirm the general opinion. The Subaru

is not a suitable engine for a Pulsar. With the 912, it is already

noseheavy, with the battery in the back.



And I am an aeronautical engineer!



Sonja



On 11/12/13, ar99kid <ar99kid(at)gmail.com> wrote:

 	  Quote: 	
		   



 well seems that this engine is a REALLY  heavy problem ! i will reconsider

 my options ...from all your inputs here , this is a no no situation . i was

 hoping that this body will be stronger and can handle some margin in engine

 weight .

 still 6500 usd which will get here with shipping and all taxes like 9000usd

 is too much ! jabiru , maybe vw ...something to get  70-80hp and still be in

 the 75 kg limit



 thanks for your help !





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=412879#412879

kymc(at)internode.on.net
Guest

Posted: Tue Nov 12, 2013 7:25 pm Post subject: pulsar xp with subaru ea81 ?

Yes Keith it did have a higher weight limit. From what I was told by people that saw the test flight attempt it appeared that the Subaru engine install was to heavy and the tail was not large enough to control the extra weight. All in all it was a disaster and after a couple of minutes it crashed. 



I am always amazed that people want to take a proven design that was designed for specific engines and then want to put something else in. Most times it is to try and save money rather than it being a better outcome than the designed installation. There appears to be plenty of example's of car engine installs that either fail or end up as a money pit and time consumer to try and get them to fit and get the cooling working correctly. There are examples of RV's in the US in particular that have Subaru engines removed when they are sold to avoid any liability from having a car engine as the power plant.



Personally I have no desire to be sitting in an aircraft that has me wondering if the engine is going to stop or parts of the plane are going to start falling off in light turbulence.



Kym

Australia

RV6A



On 12/11/2013, at 9:36 PM, Keith Palmer wrote:



[quote] 

 

 Kym,

        To add to this the SP100 was also built to take a heavier engine, I don't know the SP's MAUW. must be 1200lb plus ?

 

 K'd

 

 ---

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