Actual Flying Rotax Installs

[Kai]

Finally got old #0525 in the air again.

This time with a 120 HP EdgePerformance EP915ECI powerplant (R912ULS refinement)

First impressions:

I am too hamfisted on the throttle when on the ground: very little goes a long way!

On the ground the coolant quickly boils: get your finger out! But airborne oil and coolant temps drop like stones: they are FAR too low.

Engine torque is at least double that of the Jab 33A: will take some practice getting used to. It turns hard left on the ground and needs a boot full of right rudder. Climbs like there is no tomorrow, is at least as fast as with the 120HP Jab. Prop is a Sensenich 64x82 fixed pitch.

Somehing funny going on with the VSI gage- the pointer is all over the place. Static???

We’re getting there!

Thanks
Kai

[SonexN76ET]

Congratulations Kai! Well done!

Jake

[Kai]

All,

Further to my previous posting, I believe I have solved the static issue.

Old #0525 originally had the cheapy ASAS pitot/static tube- I’ve had my suspicions about this one for a long time.

I decided to relocate the static pickup point to the inside of the rear fuselage cone. Problem solved. At 1500’ amsl on a windless afternoon now both the gps and the asi correspond to within a few knots. I speculate that relocating the static to behind the panel under the glareshield, just as Sonex does with the factory prototypes, would give similar results.

Question: will plugs with out of spec gapping result in poor idle?

Thanks
Kai

[killerfish72]

Nice! Any pics from the front? I've been considering a B Model build with an Edge Performance Rotax. Would like to see how you did your cowl.

[Kai]

Sorry,

I’ve tried to upload a photo, but the system won’t let me. If you pm me, I could mail some pics to give you an idea.

However, you should know that this sheet thing came about because I hate composit work, and not because of any issues with the cowling Sonex supplies. In addition, I am not using the Sonex engine truss for the R912. This is because of cg worries since I am using a 40l seatback fueltank. In addition I had to make space for my twin radiator cooling setup. Further I far too late in the finishing process realized that Sonex is using a 2” prop flange spacer in combination with their own cowling.

I am therefore perfectly confident that it is entirely possible to use the Sonex supplied composite cowling without too many changes provided a more standardized setup is selected.

Thanks.

[Kai]

All,

There are a little more vibrations in the airframe than I appreciate, and the indications are I should probably move my prop a little further forward- say 1” or so (?).

Anybody knows where I could get hold of a prop spacer? (ASAS is out of stock).

Thanks
Kai

[13brv3]

Warp drive list some, but no idea if they're in stock.
https://warpdriveinc.com/propeller-accessories/

I think Saber is the one who makes most of the extensions, so maybe try them as well.
https://sabermfg.com/extensions

Rusty

[WesRagle]

Hi Kai,

The Sonerai I'm working with has Saber extension on it. Beautiful piece.



I think the guy that makes them is local to me at 0TX0.

Wes

[Murray Parr]

Kai,
Answer to your Question: will plugs with out of spec gapping result in poor idle?

Plugs not firing properly usually show up as engine missfire at light engine loads, usually just above idle. The reason for this is there is not as high voltage being supplied. If you have missfire at heavier engine loads it could be the plug wires or connectors or even the coils. Do you have the idle mixture set up correctly?

Murray

[13brv3]

Hi Kai,

The Sonerai I'm working with has Saber extension on it. Beautiful piece.

Wes

Indeed they are. I have a 3" Saber on my Onex, which I may or may not need. It was from the previous installation of the 912, so I've just left it there for now. If I don't need it, I may just set it on my desk so I can look at it all day :-)

Rusty