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Rotax engines
Posted:
Mon Mar 03, 2014 4:43 pmby patrebert
Am building a Onex, considering 912 power. How have Sonex builders using this engine dealt with the lighter weight compared to Aerovee? More forward engine mount? ballast?
Re: Rotax engines
Posted:
Mon Mar 03, 2014 9:04 pmby fastj22
What weight are you using for the 912?
I thought the 912 was much heavier than an Aerovee.
Re: Rotax engines
Posted:
Mon Mar 03, 2014 9:41 pmby Mike53
Re: Rotax engines
Posted:
Mon Mar 03, 2014 9:51 pmby fastj22
140.6lbs is pretty impressive. like the Jab 2200, I would expect you would need to build an engine mount that hangs it 6 to 8 inches forward from the Aerovee mount.
Re: Rotax engines
Posted:
Tue Mar 04, 2014 1:18 pmby SvingenB
Turbo and CS propeller
Re: Rotax engines
Posted:
Thu Mar 06, 2014 11:55 amby patrebert
The 140 pound number doesn't include muffler (8.8 lbs) and radiator (2.2 lbs), neither of which are typically included in an aerovee installation. And what? 2-4 lbs of coolant? Getting to be almost a dead ringer for Aerovee weight, at least with nikasil cylinders. One of the main attractions of the iS to me was its low cruise fuel flow, but do I understand correctly that that's also available on the carbureted engines with the addition of an available mixture control modification?
Re: Rotax engines
Posted:
Thu Mar 06, 2014 6:29 pmby Mike53
Maybe i'm missing something but according to that link I put up those are included in the weight :?:
Re: Rotax engines
Posted:
Thu Mar 06, 2014 6:51 pmby rizzz
Mike53 wrote:Maybe i'm missing something but according to that link I put up those are included in the weight :?:
Yes, that was my understanding as well.
140lbs is complete "installed weight" including exhaust system, radiators etc. Excluding those the engine only weighs 124lbs.
The 160lbs stated for the aerovee on the aeroconversions website however does not include exhaust and a few other things.
Re: Rotax engines
Posted:
Fri Mar 07, 2014 9:34 amby patrebert
I'm working from the Operator's Manual for Rotax Engine type 912i Series, page 6-2:
912 iSc/iS
63.6 kg(140.2 lb)
exclusive of: engine suspension frame, exhaust system, fuel pumps assy, cooling baffle, radiator, oil cooler.
The iS is a bit heavier; perhaps you're thinking of the ULS numbers.
By the way, does anyone know what the engine suspension frame weighs?
Re: Rotax engines
Posted:
Fri Mar 07, 2014 10:00 amby patrebert
Realized my original post didn't specify iS, sorry bout that. Am considering both now though, does anyone have experience with mixture control on the carbureted engine?