Jabiru powered Murphy Rebel

[rshannon]

Greetings All,

 

To get rid of that "darn message" I'm offering some introductory info.

 

I'm a relatively new pilot, having trained and tested in a J-3 clipped wing in 2005. I've built a Murphy Rebel, N254MR, powered by a Jabiru 3300, which made its first flight on July 17, 2010, and currently has 160 TTAFE. I'm very happy with the plane, and flew it from my home at WA59 in Washington state (US) to Oshkosh last summer. And back!

 

As far as I know, it is only the second Murphy Rebel ever to be powered by the Jabiru engine. (The only other I've heard of is in eastern Canada.) I've always suspected there must be another Jabiru-powered Rebel somewhere, most likely in Australia. If anyone knows of any others, anywhere, please advise.

 

Best,

 

Ron

 

 

[jetboy]

http://www.kiwiflyer.co.nz/KiwiFlyer-Issue-14-ZK-Review-OctNov2010.pdf

 

the print is hard to read but I've seen this "Wild Thing" and it doesnt look any different to the Rebel.

 

Ralph

 

 

[dazza 38]

Hi Ron, I have seen a few Rotax 912 and 582 powered renegades here.I have not came across any Jabby powered ones. Rotax is mainly used because they can swing a large diametre prop via there gear box. What prop size are you running Ron?

 

 

[rshannon]

There are Rebel copies and imitators out there, for sure.

 

Ron

 

 

[rshannon]

Hi Ron, I have seen a few Rotax 912 and 582 powered renegades here.I have not came across any Jabby powered ones. Rotax is mainly used because they can swing a large diametre prop via there gear box. What prop size are you running Ron?

As recommended by Jabiru and Sensenich, I have a Sensenich 68x38 composite-covered wood fixed pitch. It will over speed a bit in cruise at WOT but I don't cruise (nor race/chase) at WOT. Otherwise, it works great. Commonly loaded around 1300 lbs., it gets off the ground in a hurry, climbs ~750-800 FPM at 72 MPH, and cruises ~103 MPH TAS at 2750 RPM, burning 6 GPH, so I'm happy. [iMHO, the old debate over Jabiru's direct drive prop tip speeds-- been there -- is not worth reviving.] When this prop wears out, I might get a 68x40, but it's not worth doing until then.

 

Ron

 

 

[facthunter]

My only concern is with prop diameter (re efficiency, which you're not troubled by) and with a draggy plane and engine cooling at the moderate cruise speed that a Rebel does. ( unless it's overpowered) Jab engines are not easy to cool. Nev

 

 

[rshannon]

I've had no trouble cooling mine, including climbing in 90+F OAT on the Oshkosh trip. It's an early hydraulic lifter model, S/N 1014. I use a Jabiru nose bowl and their std. fiberglass cyl. head baffles (with air dams added to the intakes) and a Positech P20002C oil cooler. Nothing special about the cowl otherwise; it has an exit area roughly 3 times the total air inlet area, as is commonly recommended, and is otherwise pretty tight.

 

The one thing I have which may be somewhat unusual is a dedicated "sump fin plenum" -- an aluminum tray carrying air down and along the sump fins, which was suggested by Jim McCormick at Jabiru Pacific (US). See http://n254mr.com/node/476 The tray has its own small intake just under the prop. See http://n254mr.com/node/587 A closed cell foam block with a slot through it is attached to the nose bowl behind the dedicated input slot under the prop, and butts up against the engine at the top of the tray, to channel a separate stream of air across the sump fins. See http://n254mr.com/node/755 The prop pushes air through the tray, cooling the fins, even at idle, holding for takeoff or whatever. The Jabiru nose bowl has a separate "snout" intake for the oil cooler at the bottom of the cowl, of course.

 

It's still possible to have difficulties with Jabiru cooling -- like many other engines -- but I think overall the engine got an unfortunate rep on that score from the early models, and probably some lack of experience with the engines in the builder community early on as well. There have been a lot of improvements in both since then. :-) Just my 3c.

 

 

[facthunter]

Well you have gone into it. Would you consider installing between cylinder baffles as Continental and Lycoming do? While the heads may run cool the cylinders in many motors show signs of local overheating. I prefer the non hydraulic lifters as you know what is happening if the clearances change.

 

I have a reasonable amount of time in a Rebel with a 100HP Rotax fitted. They fly like a real aeroplane. Nev

 

 

[rshannon]

Well you have gone into it. Would you consider installing between cylinder baffles as Continental and Lycoming do? While the heads may run cool the cylinders in many motors show signs of local overheating. I prefer the non hydraulic lifters as you know what is happening if the clearances change.I have a reasonable amount of time in a Rebel with a 100HP Rotax fitted. They fly like a real aeroplane. Nev

The Jabiru baffles have small downward reflectors inside on the top, positioned between cylinders. I do not use the small "gull wing" inserts between cylinders Jabiru originally provided. Not needed in this installation. Someday I might try the metal cylinder baffle system Sonex puts out for the 3300 -- just out of curiosity. Otherwise I've no inclination, much less reason, to mess with them.

 

The Rotax is also a fine engine.

 

Ron

 

 

[Gnarly Gnu]

Welcome Ron!

 

Can I ask how did you go with Murphy Aircraft Manufacturing? Are they still in business? I tried phoning them (they never answer) and emailing both tech support and the owner over a period of some months now, can never get a response not even a one-liner. Figured Murphy builders are out on their own after kit purchase.

 

 

[rshannon]

I got my partially completed kit in 2006, and am very happy I did. It's a great airplane. Murphy Aircraft Mfg. (MAM) is still in business, though with only a skeleton, part time staff. It is obvious these are tough times for most companies in general aviation, a notoriously difficult business arena in the best of times. Although MAM has received criticism for lack of responsiveness, some of it quite justified, it's worth noting that MAM is one of the very few suppliers that have remained in business and continued to supply its customers for well over 20 years. Darryl Murphy is honest, and has never failed to deliver an order for which he accepted money, eventually. That's more than can be said for a number of others who have come and gone.

 

You didn't indicate the subject of your inquiry to MAM. However, if you need tech support -- or any support for that matter -- I would highly recommend you post your inquiry to the very helpful and responsive Rebel Builders List. You can sign up for the list and use the archives by going to http://www.rebelbuilders.net (The website will soon be upgraded. That URL, will direct you to Mike Davis's server now, but will soon be the new standard address.) The exceptional quality of advice from and camaraderie of this group accounted for perhaps 30% of my decision to get a Rebel project in the first place, and I've never been disappointed in those expectations.

 

 

[Gnarly Gnu]

Thanks for that info Ron, I did check out the rebelbuilders forum some time back but found it a bit difficult to follow, seemed a bit like the old 'bulletin board service' layout from the days before the internet so a new website will probably help a lot.

 

All the best with your flying!

 

 

[bosleyboy]

Greetings,

 

Here is another Murphy rebel with a jabiru solid lifter in front, can you tell me your carburator tuning needles

 

Regards

 

Edwin

 

 

 

 

[rshannon]

Thanks for the photos, Edwin. It looks like a Canadian registration, though the photos are small for these old eyes. :-) If so, it may be the only other Jabiru-powered Rebel I had heard of when writing on this thread above. Since then, at least one other was built and flown in Australia, though it was involved in a non-engine related incident and is no longer flying.

 

I have never used the std. Bing carburetor so can't comment on that setup. There is a lot of info about it on the [jabiruengines] Yahoo Group. I originally used the Sonex Aerocarb, with a #3 needle that I modified slightly for increased mixture at the high open throttle range. I was happy with it (still have it if anyone's interested) except my particular installation required a circuitous throttle cable route which produced too much friction, something I wasn't able to resolve. At roughly 60 hrs., I changed to a Rotec TBI-40 throttle body, which allows a much shorter and direct throttle cable routing in my particular setup. With some simple vanes inside the upstream 2-1/4 intake tube to control turbulence, the Rotec produces an even fuel distribution (EGT's) and works great.

 

 

[bosleyboy]

Greetings All,To get rid of that "darn message" I'm offering some introductory info.

 

I'm a relatively new pilot, having trained and tested in a J-3 clipped wing in 2005. I've built a Murphy Rebel, N254MR, powered by a Jabiru 3300, which made its first flight on July 17, 2010, and currently has 160 TTAFE. I'm very happy with the plane, and flew it from my home at WA59 in Washington state (US) to Oshkosh last summer. And back!

 

As far as I know, it is only the second Murphy Rebel ever to be powered by the Jabiru engine. (The only other I've heard of is in eastern Canada.) I've always suspected there must be another Jabiru-powered Rebel somewhere, most likely in Australia. If anyone knows of any others, anywhere, please advise.

 

Best,

 

Ron

[dazza 38]

I dunno why I didn't mention this in my post #3. But there is a Jabiru powered Murphy Rebel at Boonah SE Qld. I know the owner and he is a member on this site. I won't mention his name as this is a public site and I do not have his permission .

 

 

[rshannon]

Thanks for the info. If he's a member here, perhaps you could ask him to PM me. It would be fun to connect.

 

 

[dazza 38]

Thanks for the info. If he's a member here, perhaps you could ask him to PM me. It would be fun to connect.

I could do that. Consider it done.