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----- Original Message -----

From: Greg Griffiths

To: [email protected]

Sent: Sunday, July 31, 2022 1:25 AM

Subject: Re: [XAIR] replacement engine

Hi Seamus,

Do you have any drawings or sketches with some measurements for the 912? My Xair (std) has been on a Jabiru since new. Managing the cht temps was a full time job, I tried many different duct mods and did manage to get below the 350°f but that was also using fuel cooling which carbons the engine and reduces performance. I am at the stage of fitting a new engine and the new Jabiru ones don't use the same mount, exhaust or prop flange also untested in out of cowl fitment so could have same?problem as current. Like most of the group there really isn't a good reliable engine like the 912 so that's where I am headed, just need any info on mounting.

My Xair has a cog of 12 from memory (away from home so can't look at my book to check) always flew very well tho fairly heavy on fuel because of the rich mixture. Mount was supplied by Jabiru but they don't make one for the new engines. I have been working with a LAME who thinks we can use existing mount frame and weld on the 912 firewall mount, apparently Randkar never made the mount although my assembly manual specifies one in the drawings. So that's where we are at the moment so any info would help.

Thanks

On Fri, 29 Jul 2022, 6:48 pm Seamus O'Donnell, <etronics@...> wrote:

your performance with the 912 is not that good, you are flying at?a very high rpm,?the?one I built years ago cruised at 4200 55kts never burned more than 12 litres and was also using the DUC prop, have you tried changing pitch on prop

weight and CG is important and the?majority of the UK xairs have a very forward CG, all xairs no matter which engine fitted fly much better with an aft CG and especially the falcon which was never as good as the standard xair

?Seamus

----- Original Message -----

From: Jonathan Webb

To: [email protected]

Sent: Friday, July 29, 2022 9:45 AM

Subject: Re: [XAIR] replacement engine

I have an X-Air F? ( Falcon in the UK ) with Rotax 912 and it works very well.? Performance is no greater than a 2 stroke but much greater reliability. Theoretically it should use less fuel but mine burns around 14 litres an hour. Previous owner said it burnt 12 litres an hour . The difference might be because I fitted heated carb bodies when I bought it to prevent carb ice.

If attachments work there is a photo of the engine installation attached.? The Engine mount is special for the 912 and the forward engine struts are shortened.

There are some weight concerns. Mine was the development aircraft and has lightweight wheels, floor and originally had a smaller single tank.

It now has double tanks ( 55 Litres )? and as I fly alone a long range tank with another 20 litres, so now aircraft endurance is far greater than pilot endurance !! - more than 5 hours.

In the UK there are a couple flying with the D-motor which seems an interesting combination.? The only thing I don't like with the 912 is flying with high revs ( cruise 4800-5000 rpm ) which makes for a noisy cockpit although a recent Bose A20 has improved the situation. The D-Motor , like the Jabiru flies with half the revs so would be more comfortable but for me reliability is the No consideration.? I like the D Motor but would want to wait a few years to see how the reliability is before flying with one.


Regards,

Jonathan

On 29/07/2022 10:13, Michael Coates wrote:

Too heavy for the X-Air Standard....??? They own the X-Air Airframe as their test bed but cant use it because of the weight etc....???? However it looks promising !

Clive Cunningham wrote on 29/07/2022 5:27 pm:

Keep an eye on Radial Motion. 3 cyl air cooled radial engine being made in Australia. Looks like a winner!

---

Clive Cunningham

K&M HD Motorcycles

U2 5-9 Kingston Ave?

Richmond?

South Australia 5033??

Ph +61 8? 8234 1090?

kmmotor@...

-- 
With regards,    Michael Coates

AU +61 7 5522 0583
USA +1 213 984 1237


PIPISTREL AIRCRAFT DEALER OF THE YEAR 2012
Winner of the EAA August Raspet Award 2012
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mailto:mcoates@...

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