New UL Power Engine Mount

We just received the shorter Mount from Russ at http://mccutcheonmetalfabricationaviation.com.
Excellent workmanship, fits like a glove.

Next step is do a weight and balance to confirm the new CG.
link to the pictures https://picasaweb.google.com/111690756223683866568/ScrapbookPhotos#

Thanks for the kind words AL, it was a fun project, I’m glad you asked me and I was happy to help you with it, I look forward to hearing your W&B results. There are more photos up on the website for anyone interested in looking.

New UL Mount Weight and Balance

We just weighed our RV 12 with the UL 260Is engine.
The new mount is 5" shorter
Avionics, flight instruments, baffling, cowling and seats were included.
The weights do not include the final wiring.


Total 693 lbs Empty CG 80.42"
Nose 144 lbs
Left Main 268 lbs
Right Main 280 lbs

Glad to see you are taking the steps to properly engineer the engine installation Al (even if it means some backing up - redo).

Is that weight also with engine oil and propeller?
If so, the weight is looking very good.

I am also wondering about battery power for the ignition. Does UL recommend a separate back-up battery for the ignition system that is isolated from the rest of the electrical system, that would keep the engine running in the case of a total electrical failure?

Alschief said:

We just weighed our RV 12 with the UL 260Is engine.
The new mount is 5" shorter
Avionics, flight instruments, baffling, cowling and seats were included.
The weights do not include the final wiring.


Total 693 lbs Empty CG 80.42"
Nose 144 lbs
Left Main 268 lbs
Right Main 280 lbs

Click to expand...

Hi AL,

For myself and others who don?t know the RV-12 W & B, is this where you were hoping to end up?

Redesigned UL Power Engine Mount

Reference the question on the CG Range

The established CG Range is 80.49 to 85.39. At his time we are just slightly forward of the limit.

rvbuilder2002 said:

Glad to see you are taking the steps to properly engineer the engine installation Al (even if it means some backing up - redo).

Is that weight also with engine oil and propeller?
If so, the weight is looking very good.

I am also wondering about battery power for the ignition. Does UL recommend a separate back-up battery for the ignition system that is isolated from the rest of the electrical system, that would keep the engine running in the case of a total electrical failure?

Click to expand...

Yes, the weight includes oil (In the Containers at the correct ARM) and the propeller.

UL does not make a backup battery recommendation, however we intend to provide an alternate battery source.
UL offers dual fuel pumps which we have installed. Redundant ignitions are part of the package we are installing.
UL Power does offer a second ECU which we have not decided to purchase at this time.

I may have not been clear on my initial post concerning the direction we are proceeding.
This is a fine kit that we have an opportunity to explore a different propulsion system.
We intend to take the steps necessary to make this a properly engineered installation.
We had always understood that changes would be necessary to stay within the flight envelope and established practices.
The original mount was our first attempt to establish a base line then to proceed forward.

We value the observations and input from the community, please keep them coming

Engine

Thanks for all the work you are putting into this for us there Al. I'm sure there will be more people interested in this engine installation as you get airborne! I know I sure am!

Ul engine Option

Al not haveing seen a RV12 but is there a possibility of mounting the twin fuel pumps & Filters and associate plumbing under the floor in the fuel tank area to help with the COG Question?? Just a suggestion mate .......
Cheers & keep up the great work!

Fuel Pump Location

splitty said:

Al not having seen a RV12 but is there a possibility of mounting the twin fuel pumps & Filters and associate plumbing under the floor in the fuel tank area to help with the COG Question?? Just a suggestion mate .......
Cheers & keep up the great work!

Click to expand...

It might work there, however the area also has the push pull tubes and the original low pressure fuel pump.
The forward tunnel area where the Fuel flow sender and fuel valve are located might be better location.
We decided to minimize the exposure to high pressure (43 PSI) fuel to outside of the cockpit.
We are leaving the low pressure fuel pump that is mounted adjacent to the fuel tank as a potential boost source.
f we need more aft CG a shorter mount could be constructed as there is still additional room between the engine and firewall.

Thanks for the question

lightest RV12!

Al at 693lbs without paint, you are probably the lightest RV12. I know there is one that is about 700lbs and the jabiru2200 powered 12 is 705 lbs.
You definitely build light. I think this is excellent.

The cg @80.42" is pretty good too considering it will move aft and very likely withing the limits after paint. Did you use the Avionics kit from Vans or your own panel?

Looking good.

Rahul

Alschief said:

We just weighed our RV 12 with the UL 260Is engine.
The new mount is 5" shorter
Avionics, flight instruments, baffling, cowling and seats were included.
The weights do not include the final wiring.


Total 693 lbs Empty CG 80.42"
Nose 144 lbs
Left Main 268 lbs
Right Main 280 lbs

Click to expand...

RV 12 Weight

kmtck said:

Al at 693lbs without paint, you are probably the lightest RV12. I know there is one that is about 700lbs and the jabiru2200 powered 12 is 705 lbs.
You definitely build light. I think this is excellent.

The cg @80.42" is pretty good too considering it will move aft and very likely withing the limits after paint. Did you use the Avionics kit from Vans or your own panel?

Looking good.

Rahul

Click to expand...

We still have some wiring to do. No paint on the inside or outside.
Seats were weighed but no carpet or side panels. Most of the credit goes to the engine and accessories as supplied.
We are suppling our own Avionics as we did not wish to wait several more months for the factory equipment
We will keep you posted as we progress.


AL

Empty Weights!

What you really want is an empty Wt CG around 81.9 so that when the airplane is at MTOW you are almost back against the rear limit. This CG would be based on and empty weight of around 740lbs. If you are lighter you may be able to move it forward some. Example of this would be 2 200lb guys, full fuel, and some small bags in the baggage compartment. Be cause when you burn off fuel the CG moves forward. This is an example of how perfectly balanced the airplane is with the Rotax engine. So when trying new engines there will be alot of trial and error and moving of somethings to try to achieve this perfect harmony. Ive never seen an RV12 that was built as an ELSA come in under 710 lbs when it was all done and flying. Of course being built as an EAB anything goes. There is a lot of empty weight comparisons in another thread here on the form around 2010. Here is a link to that thread.
http://www.vansairforce.com/community/showthread.php?t=58958&highlight=weight
I believe all the airplanes discussed were buit as ELSAs. There were originally 5 Extra sub kits you could have purchased at the time. Adding any of these kits changed the empty weight of the Airplane. On Vans web site you can down load the POH and go to page 4-3 and see an example of an average weight and balance computation. Good luck in your new engine endeavor.