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What will you replace your rotax 447 with?

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Keith84

Joined: 26 Jun 2015
Posts: 11

Posted: Fri Oct 16, 2015 10:03 am Post subject: What will you replace your rotax 447 with?

I have 70 hours on my 447 after 3 months of flying and I am starting to think ahead. Instead of rebuilding the rotax wouldnt it be wiser to buy a current production engine? 

I spent sometime on jack b harts page and he it looks like he is a big fan of the mz4.

It seems our current options are the mz34, victor1+, maybe mz201, F-33, and kawasaki 340. Is there any I am missing?  What your opinions on what or if to replace the 447 with?

_________________
98' Kolb FireFly

stuart(at)harnerfarm.net
Guest

Posted: Fri Oct 16, 2015 11:42 am Post subject: What will you replace your rotax 447 with?

Well the price of a 447 rebuild, especially if you have the mandatory crank

replacement, puts you well on the way towards a new engine. 



The new Hirth would be way up on my list.  The 2702 is the closest

replacement for the 447. Also very interesting is the F-23 opposed cylinder

unit. Weighs a lot less and has more HP than the 447.



At the rate I am putting hours on my 447 it will probably last me the rest

of my life.   At the very least, it should last until there is a good

electric alternative. With 5 Gal. of fuel providing 1.5 hours of flight for

a weight of 130# the Rotax is a pretty good setup. But with a 10# motor, how

much battery weight does it take to fly 1.5 hours?  Not there yet, but

hopefully in the next few years...



On the other hand, if your 447 is performing well and can be rebuilt for a

reasonable price, you might be able to get another service cycle out of it.

By then, who knows what will be available?



A tough decision that only you can make when it comes to

reliability/convenience/dollars, etc.



Stuart

--

Keith84

Joined: 26 Jun 2015
Posts: 11

Posted: Fri Oct 16, 2015 4:13 pm Post subject: Re: What will you replace your rotax 447 with?

It really seems like electric is a long ways away. Even when it becomes possible in a part 103 application I assume it will cost a fortune. Interestingly enough, I met a fellow a few months ago that designed his own plane and is going through the process of getting his plane certified (through the faa?). He said it would be an electric hybrid 5 passanger plane. It would have a very small deisel generator onboard that would contine to charge its batteries in flight. I forget what the performance specs were but they pretty impressive. Anyways, i doubt such an idea could be impletmented in a part 103 plane, but who knows!!!

_________________
98' Kolb FireFly

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Sat Oct 17, 2015 4:53 am Post subject: What will you replace your rotax 447 with?

Parts will be available for that 447 for the next hundred years. Keep it and enjoy the performance and reliability 



Dennis "Skid" Rowe

Mk3, Rotax 670, 

Leechburg, PA



 	  Quote: 	
		   On Oct 16, 2015, at 2:03 PM, Keith84 <keithdienelt(at)yahoo.com> wrote:

 

 

 

 I have 70 hours on my 447 after 3 months of flying and I am starting to think ahead. Instead of rebuilding the rotax wouldnt it be wiser to buy a current production engine? 

 I spent sometime on jack b harts page and he it looks like he is a big fan of the mz4.

 It seems our current options are the mz34, victor1+, maybe mz201, h-33, and kawasaki 440. Is there any I am missing?  What your opinions on what or if to replace the 447 with?

 

 --------

 98' Kolb FireFly

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=448014#448014

rowedenny

Joined: 09 Mar 2008
Posts: 338
Location: Western PA

Posted: Sat Oct 17, 2015 4:57 am Post subject: What will you replace your rotax 447 with?

Any good machine shop can rebuild the cranks with new rods and bearings for a fraction of the price of a new crank. The rods and bearings are the only wear items



Dennis "Skid" Rowe

Mk3, Rotax 670, 

Leechburg, PA



[quote] On Oct 16, 2015, at 3:42 PM, Stuart Harner <stuart(at)harnerfarm.net> wrote:

 

 

 

 Well the price of a 447 rebuild, especially if you have the mandatory crank

 replacement, puts you well on the way towards a new engine. 

 

 The new Hirth would be way up on my list.  The 2702 is the closest

 replacement for the 447. Also very interesting is the F-23 opposed cylinder

 unit. Weighs a lot less and has more HP than the 447.

 

 At the rate I am putting hours on my 447 it will probably last me the rest

 of my life.   At the very least, it should last until there is a good

 electric alternative. With 5 Gal. of fuel providing 1.5 hours of flight for

 a weight of 130# the Rotax is a pretty good setup. But with a 10# motor, how

 much battery weight does it take to fly 1.5 hours?  Not there yet, but

 hopefully in the next few years...

 

 On the other hand, if your 447 is performing well and can be rebuilt for a

 reasonable price, you might be able to get another service cycle out of it.

 By then, who knows what will be available?

 

 A tough decision that only you can make when it comes to

 reliability/convenience/dollars, etc.

 

 Stuart

 

 

 --

stuart(at)harnerfarm.net
Guest

Posted: Sat Oct 17, 2015 10:19 am Post subject: What will you replace your rotax 447 with?

Well there are already several Part 103 electrics out there. Most of them

cannot fly for much more than 30 minutes without putting enough batteries

onboard to go over the weight limit.



Battery technology is advancing, so maybe it won't be that long before we

can get an hour of flight out of 75# of battery. 



Price is always a consideration, but that too is coming down. You have to

factor in the price of the electricity itself along with the replacement

cost of the batteries divided by the hours of service they provide. Then

compare that to the price of fuel, oil, regular maintenance and overhaul of

a gas engine.



Granted, it is not there yet. By the time I am ready for a rebuild of the

447, I expect things will have changed significantly.



It is something I sure hope I get to try out some day.



Stuart



--

zeprep251(at)aol.com
Guest

Posted: Sat Oct 17, 2015 3:39 pm Post subject: What will you replace your rotax 447 with?

Stuart,I understand the recommended tbo for the 447,but well cared for 503’s go 750 hrs or better and JBM,s 582 has over 1300 hrs on all original parts except gaskets.Just decarbon and inspect regularly.You may never have to scrap it.

[quote] On Oct 17, 2015, at 2:18 PM, Stuart Harner <stuart(at)harnerfarm.net> wrote:

 

 

 

 Well there are already several Part 103 electrics out there. Most of them

 cannot fly for much more than 30 minutes without putting enough batteries

 onboard to go over the weight limit.

 

 Battery technology is advancing, so maybe it won't be that long before we

 can get an hour of flight out of 75# of battery. 

 

 Price is always a consideration, but that too is coming down. You have to

 factor in the price of the electricity itself along with the replacement

 cost of the batteries divided by the hours of service they provide. Then

 compare that to the price of fuel, oil, regular maintenance and overhaul of

 a gas engine.

 

 Granted, it is not there yet. By the time I am ready for a rebuild of the

 447, I expect things will have changed significantly.

 

 It is something I sure hope I get to try out some day.

 

 Stuart

 

 --

Ducati SS

Joined: 15 Oct 2009
Posts: 93

Posted: Sun Oct 18, 2015 4:36 am Post subject: Re: What will you replace your rotax 447 with?

Polini Thor 250

Herbgh(at)nctc.com
Guest

Posted: Sun Oct 18, 2015 7:02 am Post subject: What will you replace your rotax 447 with?

Single cyl....4100 bucks...a bit exorbitant....and 1000 bucks for dual 

spark!!  Herb



On 10/18/2015 07:36 AM, Ducati SS wrote:

 	  Quote: 	
		   



 Polini Thor 250





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=448042#448042






	


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Signature text;  Add catchy phrase here..

Ducati SS

Joined: 15 Oct 2009
Posts: 93

Posted: Sun Oct 18, 2015 9:01 am Post subject: Re: What will you replace your rotax 447 with?

Not really a bad deal, take the cost of a new 447 when they were in production and add in a B box. Polini has reduction built in. Single cylinder is OK as long as vibration is addressed, Polini has a counter balancer. I will be able to put my full enclosure back on along with the larger wheels and still be well below 103 weight limit. I do not care for the reed induction but that is the price to be paid for good performance in a small two stroke. Keep waiting for a truly modern two stroke for aircraft use, this is not it, but it is a large step in that direction.

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Mon Oct 19, 2015 1:42 am Post subject: Re: What will you replace your rotax 447 with?

 	  Keith84 wrote: 	
		   it would be an electric hybrid <snip> deisel generator onboard that would contine to charge its batteries 	




Hmmm.. unless both electric and diesel could individually turn the prop I think I'd call it a diesel-electric instead of hybrid (being a Prius owner). I am interested in this concept- not because it is so unique exactly, but because with the accompanying weight and conversion inefficiencies I can see no advantage. 

- converting rotational power to electric (alternator) costs in efficiency

- transmitting electric through the wire costs (very small)

- converting electrical to chemical in the battery (charging) costs

- converting chemical to electric (drawing on the battery) costs

- converting electrical to rotational (the motor) costs 

Then there is the ever-present weight of the engine even when it isn't being used.

But still it would be interesting to learn more about this plane, the fella must be quite an innovator. If he has only ONE really good idea in there he has made a contribution to us all.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Mon Oct 19, 2015 1:45 am Post subject: Re: What will you replace your rotax 447 with?

 	  rowedenny wrote: 	
		  Any good machine shop can rebuild the crank 	




Motorcycle shops have been working with pressed-together cranks for generations.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Mon Oct 19, 2015 1:50 am Post subject: Re: What will you replace your rotax 447 with?

 	  Keith84 wrote: 	
		  maybe mz201 	




The MZ201 has some attractive features, rpm, weight, power- but it is free air cooled. I am more attracted to the MZ202 with the direct-drive cooling fan. It doesn't have to be operated at highest power settings. Just thinking out loud- I know very little about either though I have a factory-new MZ202 on my shelf.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

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