Jabiru 3300 RV-3

Lucky Clover · #1 10-21-2012, 03:57 PM

Just ordered my rv3 kit. Will mostly be using it for cross country trips. The jabiru is 120hp but is much lighter than the other suggested engines. Will I have to worry about my cg?

gasman · #2 10-21-2012, 04:33 PM

Quote:

Originally Posted by Lucky Clover

Just ordered my rv3 kit. Will mostly be using it for cross country trips. The jabiru is 120hp but is much lighter than the other suggested engines. Will I have to worry about my cg?

Yes. So why don't you just use an 150 Lyc?

Lucky Clover · #3 10-21-2012, 04:35 PM

Having to build on tight budget. Can get a new jabiru with fwf for $24000

Alschief · #4 10-21-2012, 04:46 PM

Suggest you give the UL Power a look
It is a fine power plant.

David Paule · #5 10-21-2012, 04:48 PM

You can get a used Lycoming for less....

I flew behind a Jabiru 3300 recently and was impressed by it. The only part I didn't like was its Aerovee carb. Can't see any reason to have one of those. But the engine was smooth and powerful, light and small. Started instantly.

It's roughly 80 to 100 pounds lighter than the Lycomings, and that's bound to introduce some CG issues. If you move the engine forward, you're moving the prop forward and that reduces stability. It's not exactly a slam dunk. But if you can bring it off, you'll find a number of people interested in it.

Dave

Lucky Clover · #6 10-21-2012, 05:08 PM

The jabiru is highly supported and easily installed. Have been looking over the rv3 layout. Considering the ways to move the cg forward without having to relocate the engine forward.

N941WR · #7 10-21-2012, 06:16 PM

Quote:

Originally Posted by Lucky Clover

...Will I have to worry about my cg?

Yes but since you will need a custom engine mount anyway, have it made longer
Your bigger issue will be controlling the high CHT's the Jabirus are becoming known for.

rph142 · #8 10-21-2012, 06:37 PM

Moving the cg forward wont be too tough. If I were you I would extend the .032 front side skins, floor, and top skin. You have to cut all of these pieces to size anyway, so it won't take any longer to cut them longer.

cubdriver · #9 10-21-2012, 07:50 PM

If you want to build light, you might consider Lycoming's new o-233 116 HP engine. It is a great engine, should solve CG issues and can use a factory supported engine mou t from Vans. I have one in an RV9 and it works great. Plane is light and nimble.

highflight42x · #10 10-22-2012, 12:23 AM

There would be a *severe* cg problem in a standard RV3 with an engine 80-100lbs lighter than a Lycoming.

With such an engine, the engine mount will need to be re-designed and the fwd fuselage possibly extended. Either way, you'll have a very different structure fwd of the cockpit, implying some serious structural analysis and design work. The flight characteristics could change drastically - the farther fwd the engine, the more different the inertial characteristics will be.

This engine will require an entirely new cooling solution, new cowling, baffling, fuel and exhaust systems. These secondary tasks alone will be quite expensive. Is there a propeller for the Jabiru with the pitch/diameter needed for the RV3's speed envelope?

In short, to install an engine that the aircraft was not designed for, you will become a true experimenter. I'm not trying to persuade you not to do this, just be aware that with a new untried engine installation, it will cost much more than you originally intend, and will take 2x (or more) time to do it.

good luck!

- Steven
RV3 builder/pilot
(700+ RV3 hours)
(... 1.5 more today!)