Sonex 912is Install looks CLEAN
Posted: Thu Jan 27, 2022 12:47 pm
by killerfish72
Watched the EAA Homebuilders Week video linked here: https://players.brightcove.net/62700807 … 3553347001
Mark starts talking about the One Week Wonder Waiex B project which will have a Rotax 912is engine installed at the 57 min 10 second mark of the video. Their install will maintain the clean cowl with no extra cutouts for radiator like most Rotax powered aircraft (such as my RV12). I really like the split Radiator design as well as the Exhaust/routing… Simple. While the cockpit is small, you could conceivable have a passenger and pilot side heater controls. Pulling heat of the radiators and using an louvred baffle to vary the amount of air that passes through each radiator. Search ‘Bender Baffle’ on the Van’s Airforce RV-12 board to get an idea. The bed mount does pretty much prevent a turbo install, but I’m not too concerned about that. You could always do a big bore and get about 120hp.
I’m temped by the B Model, but patiently waiting for the High Wing. Of note, Mark also mentioned no Waiex version of the high wing. It’ll be a Sonex tail only. I’m good with that as I prefer less complexity and less weight on the tail.
Re: Sonex 912is Install looks CLEAN
Posted: Thu Jan 27, 2022 7:24 pm
by Skippydiesel
Would like to have seen the proposed, all important, cowling exit air set up.
Re: Sonex 912is Install looks CLEAN
Posted: Thu Jan 27, 2022 8:37 pm
by killerfish72
I think they said they planned to use the side exits as is to help ‘suck’ air out through the radiators. Of course there will be a bottom exit for exhaust tubes too
Re: Sonex 912is Install looks CLEAN
Posted: Fri Jan 28, 2022 1:20 am
by Skippydiesel
Most people focus on the cold air in side of the equation (the “look”), without realising the warm/hot air exit is arguably the more important from a drag minimisation perspective.
Not suggesting the design of the cowling front end isn’t important, just highlighting the need to address air in& out for optimum efficiency (function over form every time for me).
Re: Sonex 912is Install looks CLEAN
Posted: Fri Jan 28, 2022 8:55 am
by killerfish72
Agree. Watch the video. Mark addresses this
Re: Sonex 912is Install looks CLEAN
Posted: Fri Jan 28, 2022 8:15 pm
by Skippydiesel
killerfish72 wrote:Agree. Watch the video. Mark addresses this
Yeah! Sort of - in passing.
Has some similarities to the Europa cooling system design.
Will be interesting to see how this cooling system works in practice - quite a bit of extra cooling hose & connections but sometimes you just have to “bite bullet” of increased complexity & weight to get a greater “pay off”.
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 3:36 am
by garyb
My Rotax powered Sonex cowl, which is the standard horizontal split.
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 9:36 am
by bvolcko38
Is this an A or B model? What exhaust did you use? Motor mount? More pics? I am seriously thinking of going with the 912
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 10:06 am
by killerfish72
Gary’s looks like an ‘A’ model. Sonex Inc’s in the video is a B model. I would expect the same cowl on the high wing so any install on a B model from Sonex should be easily re-applied there.
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 4:46 pm
by garyb
A model Sonex standard Rotax round exhaust, I built the mount which is a hybrid of the Aerovee, Jabiru3300 married into the Rotax ring mount. The cowl was opened up for more cooling but after flying it for 180 hours I decided to restore it back to stock as I did not need the extra cooling. Also I like the look of the stock Sonex cowl. As you can see I had to put some bulges on to clear the oil filter and exhaust elbows. The prop is a 68" GT Propeller from a Tecnam P2008 which could do with slightly more pitch. Cruise is 120kts burnning less than 15 litres/h. 5200rpm. Has 190 hours Airframe and 1025 hours on the engine.
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 5:53 pm
by Skippydiesel
Hi Gary,
I like your oil cooler installation - I am going the same way. Any over/under cooling in this “department”?
If possible, a photo showing your exit air design, would be very helpful.
Your airspeed/fuel consumption is great - hope mine will be similar.
The 2 metal elbow oil lines - Rotax ? or other?
Re: Sonex 912is Install looks CLEAN
Posted: Sat Jan 29, 2022 8:16 pm
by 13brv3
I can see that I won’t be posting any pictures of my cowling anytime soon 
Rusty (Onex 912UL pending inspection)
Re: Sonex 912is Install looks CLEAN
Posted: Sun Jan 30, 2022 8:05 pm
by garyb
Skippydiesel wrote:Hi Gary,
I like your oil cooler installation - I am going the same way. Any over/under cooling in this “department”?
If possible, a photo showing your exit air design, would be very helpful.
Your airspeed/fuel consumption is great - hope mine will be similar.
The 2 metal elbow oil lines - Rotax ? or other?
Hi Skippydiesel
The metal elbows are Rotax, my exhaust sticks about 1/4 inch below the cowl which the aluminum airdam covers up.
In winter I have to tape about 3 rows of the oil cooler to maintain temps. In cruise I see around 90C and up to 110C in a long climb.
Re: Sonex 912is Install looks CLEAN
Posted: Tue Feb 01, 2022 12:16 am
by Skippydiesel
Looks great !!!
I would also be interested in:
Size of oil cooler air intake?
Did you have any problems with purging air from your oil cooler?
The last point - I am contemplating fitting my cooler, same location, but 90 degrees to yours (all fittings on the right side). My thinking is that air purging will be a breeze, cooler body will be just that little bit further from the hot exhaust pipes and I dont anticipate any down side. Your thoughts?
I will look up the Rotax part numbers for the metal oil line connections.
Re: Sonex 912is Install looks CLEAN
Posted: Tue Feb 01, 2022 1:44 am
by Skippydiesel
Gary,
I have found in Rotax parts catalogue, Section 79-20-00, page 9, Oil Radiator;
Part Number 956615 - Screw Connection Set Straight (Correct?)
Part Number 956585 - Screw Connection Set Bent (Correct?)
AND
Is PN 956585 also the fitting on your oil pump?
Re: Sonex 912is Install looks CLEAN
Posted: Tue Feb 01, 2022 3:23 pm
by garyb
Skippydiesel wrote:Gary,
I have found in Rotax parts catalogue, Section 79-20-00, page 9, Oil Radiator;
Part Number 956615 - Screw Connection Set Straight (Correct?)
Part Number 956585 - Screw Connection Set Bent (Correct?)AND
Is PN 956585 also the fitting on your oil pump?
Hi Skippydiesel
I found a used oil tank and cooler which had all the fittings on and swapped the oil pump and one cooler fitting and they are all the same metric threads, as for the part numbers the IPC I have do not match with your numbers however they are item 11 on page 6 and items 5 and 6 on page 13
Regards
Gary
Re: Sonex 912is Install looks CLEAN
Posted: Wed Feb 02, 2022 3:20 am
by Skippydiesel
A man after my own heart - I will place an advert on Recreational Flying for the same - you never know what might turn up.
Re: Sonex 912is Install looks CLEAN
Posted: Wed Feb 02, 2022 3:20 am
by Skippydiesel
A man after my own heart - I will place an advert on Recreational Flying for the same - you never know what might turn up.