Looking for O.S. 120 II Gemini advice
04-11-2017, 05:25 PM
#26
A Sig J-3 Cub like everyone else had I think..
Back then it was a Zinger 15-6 and weight was around the 15#
The prop on my OS 160 twin is a white/black Xoar 17-8 and a size smaller for a 3-blade Xoar that looks cool on a C-182...but don't have the pull of a two blade. Anything above 90 degrees I don't use it. We are at 1850 above sea level here.
Back then it was a Zinger 15-6 and weight was around the 15#
The prop on my OS 160 twin is a white/black Xoar 17-8 and a size smaller for a 3-blade Xoar that looks cool on a C-182...but don't have the pull of a two blade. Anything above 90 degrees I don't use it. We are at 1850 above sea level here.
04-11-2017, 06:50 PM
#27
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Location: Clinton Twp. MI.
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MX240,
Well I know everyone else has a cub, I wanted to avoid that and stick with a sport model. I'm considering a GP 1/4 scale RV-4 or maybe the smallish new 1/4 scale SIG T-CLIPS that I saw at the Toledo show this year. I know that the T-CLIPS in the 70 size has been a successful sport aerobatic plane. I've been looking for this NIB 120 II for some time, and now that I finally have it I want to chose just the right sport plane for it. Come to think of it, my H-9 RV-8 is marginally powered with the O.S.72a in it now and could sure use some nose weight anyway. Maybe with some careful refitting it could be done. Preliminary measurements look promising.
I'm glad that I finally found a FOX 10mm-12mm prop reamer, thanks to someone's tip on another thread. If your 120 II flew your 15 lb. cub well enough, then a 9-12 lb.sport model would have a good chance for decent performance.
Karl
Well I know everyone else has a cub, I wanted to avoid that and stick with a sport model. I'm considering a GP 1/4 scale RV-4 or maybe the smallish new 1/4 scale SIG T-CLIPS that I saw at the Toledo show this year. I know that the T-CLIPS in the 70 size has been a successful sport aerobatic plane. I've been looking for this NIB 120 II for some time, and now that I finally have it I want to chose just the right sport plane for it. Come to think of it, my H-9 RV-8 is marginally powered with the O.S.72a in it now and could sure use some nose weight anyway. Maybe with some careful refitting it could be done. Preliminary measurements look promising.
I'm glad that I finally found a FOX 10mm-12mm prop reamer, thanks to someone's tip on another thread. If your 120 II flew your 15 lb. cub well enough, then a 9-12 lb.sport model would have a good chance for decent performance.
Karl
Last edited by extra300crazy; 04-11-2017 at 06:53 PM.
04-12-2017, 10:21 AM
#28
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Guys,
I have a question for the group regarding methods to route the exhaust to the bottom of the cowl and firewall similar to the Y setup that Saito uses. Have any of you used a flexable arrangement using the items pictured?
I believe by using the header to avoid excessive bends in the flexible pipe, it should hold up better.
I'm open to ideas and suggestions.
Karl
I have a question for the group regarding methods to route the exhaust to the bottom of the cowl and firewall similar to the Y setup that Saito uses. Have any of you used a flexable arrangement using the items pictured?
I believe by using the header to avoid excessive bends in the flexible pipe, it should hold up better.
I'm open to ideas and suggestions.
Karl
04-20-2017, 07:37 AM
#29
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Guys,
I wanted to take the time to thank all of you who offered up your tips and suggestions for the operation of my new O.S. 120 II Gemini engine. Although I've been using O. S. single 4- strokes for years, the twin is a totally new thing for me. I've decided to retro fit my H-9 RV-8 with the twin. It has a 60" span, 732 sq. in. area, and currently weighs 8 lbs. 2 oz., with a wing loading of 25 oz./sq. ft. With the twin it would come out at 9 lbs. 8 oz. with a wing loading of 30 oz./sq. ft. I believe the "Hershey bar" style wing would carry the load well.
Getting the advice I neede was one of the great things about belonging to this forum, and I'm grateful to all of you.
Thanks again,
Karl
I wanted to take the time to thank all of you who offered up your tips and suggestions for the operation of my new O.S. 120 II Gemini engine. Although I've been using O. S. single 4- strokes for years, the twin is a totally new thing for me. I've decided to retro fit my H-9 RV-8 with the twin. It has a 60" span, 732 sq. in. area, and currently weighs 8 lbs. 2 oz., with a wing loading of 25 oz./sq. ft. With the twin it would come out at 9 lbs. 8 oz. with a wing loading of 30 oz./sq. ft. I believe the "Hershey bar" style wing would carry the load well.
Getting the advice I neede was one of the great things about belonging to this forum, and I'm grateful to all of you.
Thanks again,
Karl
