SonexBuilders.net

hi all,
if you are interested in longer gear legs for a sonex check out www.titaniumjoe.com

best,

michael

So I have a 912 sitting in my Sonex until I get mine in the mail. For now I’m just using it for fitment of parts so when I receive my engine, it should be plug and play! But in the meantime I have run into some hurdles but nothing that can’t be fixed. One issue is my prop flange is a little low in my cowl, but with some persuasion and effort, it’ll work fine. My major problem is that at the back of the engine, the water pump has several outlets. One of which basically rests on the motor mount which means I can’t get a hose on, if I could it wouldn’t last long, and the outlet would likely break off or develop a leak. With that being said they are pressed and glued in. However all of them are in the same position from the factory. I may be able to remove, reorient, and reinstall to help save it. I talked to Mark at Sonex and helped me with what information that he had, very nice and helpful guy. But I found out Sonex has never installed a 912, and has only drawn up the mounting system in cad to satisfy customers who want to use the engine. So, with that being said, there are some hurdles to be overcome but nothing crazy, just like any aircraft build. Here is how it sits currently. I’ve been busy installing the firewall items, wiring,mock up exhaust, and ideas for radiator locations. I will keep posting progress as it comes.

My Rotax powered Sonex should be up and flying in a couple of weeks. I will post some new photos soon.

The Homebuilt Help Rotax Installation video has been a great help. It shows how to adjust the water inlet tubes for different engine mounts. I had to purchase some water inlet tubes with different angles to get it to fit the Sonex engine mount. You have to carefully heat the water inlet tubes and very carefully unscrew them and then clean the threads and apply Locktite 243. You must note and mark the correct angle required for fitment before you screw them back into place. You likely will not be able to screw them on when the engine is seated in the mount due to clearance issues. Be careful as the threads are very fragile in the heads and on the inlet tubes. Please watch the Homebuilt Help videos as they show precisely how this is done.

I mounted my radiator to the aft and under the engine.

I am in the process of modifying my cowling. It will be about six inches narrower at the front than the Aerovee cowling and will be contoured to mate up with the larger spinner for my three bladed Sensenich propeller.

You should also check out Rotax-Owner.com for other videos and service instructions.

I modeled my installation after the Bristell LSA which is an improved version of the SportCruiser/PiperSport.

Jake

I do not have a Rotax on my Sonex, but I just recently installed a Rotax on another airplane I built. The water pump outlet also interfered with the engine mount and the standard fix was to remove the pump outer housing with the tubes. Add a bit of heat using a propane torch, and rotate it slightly. The tube is soldered in and the slight rotation doesn't seem to cause it any problems.

So with some work I have completed the install of my Rotax with the Sonex mount. With some tweaks to the water pump, elbow replacement and orientation, the Sonex mount works. I had run my engine for the first time today. It’s not yet synced and tuned but it started right up. Currently going to run it for an hour on non synthetic 10w-40 Castrol oil and a Fram filter to break in, tune, and collect all the crap, then I’ll be doing an oil change to the standard Aeroshell and Rotax filter. It’s a 912 with 84mm pistons and cylinders. I had tigged up an exhaust into duals, made a scoop that houses my radiator and oil cooler, and a few other things. I’m running a 64” 3 blade taper and nickel tipped Warp Drive. Right now this is what I have and it’s about ready to be flown. I have a DAR appointment this next weekend to get my airworthiness.

The install

Congrats, it's lookin' good! Can't wait to see it fly.

My buddy has over 1200 hrs on his Rotax 912 (80hp) in a Rans S7. He tried different types of oil and is currently settled on the Aeroshell Sport Plus 4. It's pricier, but it's what he believes his engine prefers. I personally can't tell the difference.

YMMV

Getting close to first flight with Rotax 912 ULS

Jake

Excellent Jake! I've been wondering about your progress as well.