Firewall forward kit for Jabiru/Rotax 912

[planesmaker]

what sort of $$ does this cost?

The next question to ask is what does it weigh? 0-233 lycoming at 30+kg heavier would put the 230/430 to about 410 kg or more empty! Tom

 

 

[cooperplace]

The next question to ask is what does it weigh? 0-233 lycoming at 30+kg heavier would put the 230/430 to about 410 kg or more empty! Tom

yes, agreed, it adds a lot of weight, and all at the front. Does ballast need to be added at the back as well?

 

 

[DrZoos]

Anyone know the cost of a final inspection and a reissue of an airworthiness cert for putting a rotax in a jab ???

 

 

[jetjr]

Id suggest it would definitely require rear ballast, plenty of std j200/400 have lead in tail already

 

 

[cooperplace]

Id suggest it would definitely require rear ballast, plenty of std j200/400 have lead in tail already

so how much total extra weight inc. tail ballast does (i) a Rotax 912; (ii) Lyc. O-233 add?

 

 

[jetjr]

No idea but ill make something up.

 

Mines std 3300, has 2kg in tail

 

If o-233 weighs 30 kg more, it could easliy be 4-5 kg extra in tail, or even more if forced to place it in the rear compartment.

 

Comes back to same points, in the larger jabs theres only 2 realistic options right now, 3300 or 914. Some others out there but not mainstream just yet.

 

 

[fly_tornado]

come on who wouldn't prefer a kitfox with a radial engine?

 

 

 

[DrZoos]

OK got some info from PG and from Bert Floods, Certification apparently costs not much, its more a process then a cost

 

Yes can retain 700kg MTOW with a 912 in a jab, as its the aircraft that is certified for 700kg, not the motor. Seems strange. ... but anyway...

 

So now our decision is to go 912ULS or 912is - these are my calcs from all the info i can find and verify online.

 

They refer to fuel consumption v Power of the 912uls and is

 

Please point out any mistakes, if you see find / know any.

 

The major benefit of the is is no carb ice and much lower fuel consumption at cruise which is where we will spend most our time.

 

We expect to put on a lot fo hours travelling for business and pleasure.

 

So i view it if a Rotax runs 2000hrs and costs $20,000 then its $10 per hour less the sale price of say $5000 at 2000 hours

 

A 9i2s at say $24,700 cost $12.5 per hour when selling it at TBO

 

But the fuel savings are enourmous at $2.30 ltr

 

912 ULS has 100hp at max rpm and 95hp at continuous 5500rpm uses 26.1 L / hr

 

912 is has 100hp and then only 92.5 hp at continuous 5500rpm uses 23.6 L / hr but produces 2.5hp less at this rpm

 

thus 912is produces 2.7% less power at 5500rpm and 10.5% less fuel consumption

 

at 75% cruise which is 5000rpm the 912ULS uses 20lph and makes 69hp

 

the 912is uses 16.5lph - according to the graphs and makes 67hp 5000rpm

 

so 3% less hp and 21.2% less fuel

 

Of Course this assumes the figures and graphs are accurate.

 

 

So if these calcs are right and we put 400 hours on this in two years then my way of thinking is at leats 75% of this will be done at cruise and thus saving 3.5L per hour for 300hrs. Thus $8 per hour x 300 = $2400 of the extra price paid for in 2 years.

 

or over the life of the engine its $2.47 extra per hour upfront cost, but we are saving around $8 per hour for most the hours we fly

 

whats your thoughts opinions please.

 

 

[skeptic36]

whats your thoughts opinions please.

Your fuel is expensive........

 

 

[David Isaac]

OK got some info from PG and from Bert Floods, Certification apparently costs not much, its more a process then a costYes can retain 700kg MTOW with a 912 in a jab, as its the aircraft that is certified for 700kg, not the motor. Seems strange. ... but anyway....

You can only maintain 700kg MTOW if you stay VH registered and I would question that at only 100 hp, she would climb like a slug. Wasn't the Jab 3300 120HP.

IF you change to RA Aus rego you will go back to a maximum of 600kg MTOW regardless of HP?

 

 

[DrZoos]

We r going to leave it vh... Others with jab 230 and rotax 912 uls rave about the performance, saying the 100 hp has no problems lifting the jab..

 

 

[David Isaac]

Are you going to put 4 x bums in it at only 100 HP?

 

 

[planesmaker]

I am sure it won't be too much of a slug at climbing with only 100hp at least no worse than a C 172. Though hot and high ops might use some runway. I mostly only use 100hp for takeoff in my J400 and at about 600kg gives 800'/min. Tom

 

I do have a constant speed prop though

 

 

[David Isaac]

A C172 has 160 HP, how can 100 HP not be worse at 700Kgs? The Cessna wing is completely different, but admittedly the Cessna is 1,048 Kgs, but still work it out. A C172 will climb all day at MTOW at 65knots.

 

 

[frank marriott]

" A C172 will climb all day at MTOW at 65knots."

 

Not on a hot day out west - requires step climb to keep the temps out of the red.

 

 

[David Isaac]

Frank, the only time I ever had a temp problem in one of our hire 172s over the last 30 years was when the engine cooling baffles had dislodged in one of them. It took a while to identify the problem, it actually overhead on a climb out of Mascot. Mind you I have never flown one in 40+ temps, so in those conditions I cannot say.

 

 

[frank marriott]

David

 

Yes in the hot dry conditions (and heavy)it is real - multiple different 172s including the RGs, it's quite achievable but just have to be careful and don't be in a hurry to attain altitude. Read as riding out the heat thermals. No so much with the 182/206s - the extra grunt makes a difference even though all at their respective AUW.

 

 

[DrZoos]

Are you going to put 4 x bums in it at only 100 HP?

No might have two big bums and one small bum max. if we need to go 3 up or 4 up we will hire the 172

Mainly want to keep 700kg so we can have some luggage...

 

90% of the time it will be less then 600kg

 

 

[David Isaac]

.... and don't be in a hurry to attain altitude. Read as riding out the heat thermals. ......

I must admit I had to laugh at your comment above about not being in a hurry to climb. That is absolutely the case almost under any conditions at MAUW. I used to ride thermals climbing out of Dubbo in a C172 many moons ago.

 

 

[DrZoos]

I think most often it will be well under 600 kg , but havingthe 700 kg and using it in cooler months, smooth morning flights may be useful, so no hurry to swap it for 600 kg.

 

 

[DrZoos]

Well what a difference 72 hours makes. Got back to Aus from NZ and spoke to some people in the know and also rang lots of people who have had experience with conversion or trying to convert. I cant say everything because it would be unfair to do so as some things we where told we where told in confidence.

 

But to cut a very long story short. We spoke with about 8 people who have done or tried to do conversions and the news is not as rosy as you might first think. Yes there are happy campers out there, but in short, they didnt get there quickly, cheaply or within the boundaries of what we are prepared to go thru.

 

So we have aborted the mission. Im shattered as a Jab powered by a 912is in my mind would be an amazing aircraft. But its in my opinion not achievable yet, within the time or money limits i can put into it. If i was rego 19 and doing it myself , i think i would still do it.

 

Anyhow live and learn, stumble or fall over get up and move on with a smile.

 

 

[planesmaker]

Well what a difference 72 hours makes. Got back to Aus from NZ and spoke to some people in the know and also rang lots of people who have had experience with conversion or trying to convert. I cant say everything because it would be unfair to do so as some things we where told we where told in confidence.But to cut a very long story short. We spoke with about 8 people who have done or tried to do conversions and the news is not as rosy as you might first think. Yes there are happy campers out there, but in short, they didnt get there quickly, cheaply or within the boundaries of what we are prepared to go thru.

 

So we have aborted the mission. Im shattered as a Jab powered by a 912is in my mind would be an amazing aircraft. But its in my opinion not achievable yet, within the time or money limits i can put into it. If i was rego 19 and doing it myself , i think i would still do it.

 

Anyhow live and learn, stumble or fall over get up and move on with a smile.

Dr Z you give up easy. Not such a difficult conversion. Perhaps you should come and have a look (and fly) of mine. Pm me to know more. Tom

 

 

[DrZoos]

Dr Z you give up easy. Not such a difficult conversion. Perhaps you should come and have a look (and fly) of mine. Pm me to know more. Tom

Hey its been 2 years i really love my aircraft, but still have lots of envy for a Jabirotax....the perfect RAA aircaft in my opinion.... Lots of room, power , good fuel exonomy , tough engine, tough airframe and room to put a dismantled mountain bike, fold up bike or camping stuff in it...

The only real thing against my plane is a lack of room and mtow...

 

Some days i seriously wish i had of persued the conversion. Hows yours going and are there several others around now...did PG or anyone else do a firewall firward conversion kit ?

 

 

[Downunder]

Now that the "915 is" will become avaiable, that and a J230/400 are a match made in heaven.

 

If only one company was not such short sighted......

 

 

[planesmaker]

My jab is going really well! I am really happy with it, it's a great airframe ( world class), low maintenance, strong etc, and the rotax just goes so nicely in it. Compared to a C172, it will lift more weight, climbs much better, cruises faster with 1/2 the fuel burn! What more could you want? Tom