Today's Message Index:
----------------------
1. 05:56 AM - 912 Prop (jareds)
2. 09:54 AM - Re: 912 Prop (Pete Christensen)
3. 12:40 PM - Re: 912 Prop (Guy Buchanan)
4. 06:18 PM - 912 fuel return line ()
5. 06:58 PM - Re: 912 fuel return line (Guy Buchanan)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Have my choice between props.
Just wondering which prop is best for a 912 and prefer speed over climb.
Is there some place to call that would know?
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I use an IVO ground adjustable.
Pete
On 2/24/2016 7:55 AM, jareds wrote:
> Have my choice between props.
> Just wondering which prop is best for a 912 and prefer speed over climb.
> Is there some place to call that would know?
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Jared,
You're showing some weird props there. The square tips look like
they might have come off a drone. I'll say, in general, that the longer
a prop is the more "efficient" it is because of lower induced drag.
(Think: glider wings.) The limitation on length is: 1) dragging it on
the ground; and 2) running the tips supersonic. In general, with a 912,
the prop RPM is so low you don't have to worry about #2 because #1
limits. Big /however /for the 912 is the mass inertia limitation. Since
inertia varies as the mass times distance from the hub squared you might
hit it with a really long 2-blade.
Second consideration is number of blades. In general, the fewer the
blades the more efficient the prop. (Less dirty air.) However, many say
that shorter, multi-blade props climb better, whereas longer, fewer
blade props cruise faster. Not sure why, but I suspect it's because
people over-prop with multi-blade props and subsequently run them
flatter, giving better climb performance. (Prop thrust varies as the RPM
squared, diameter ^3.5, and square root of pitch. Citation
<http://www.electricrcaircraftguy.com/2014/04/propeller-static-dynamic-thrust-equation-background.html>)
As to brand, I've seen several prop comparisons on 912s and have
never seen an appreciable performance difference between any. (Prop
design was very nearly standardized by the time of the Wright brothers.)
This excludes the radical trans-sonic stuff more recently designed, none
of which applies to our vehicles.
On 2/24/2016 5:55 AM, jareds wrote:
> Have my choice between props.
> Just wondering which prop is best for a 912 and prefer speed over climb.
> Is there some place to call that would know?
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 912 fuel return line |
In finishing up my KFIV after 24 years of building, I noticed that the
more recent Rotax 912 installation manuals call for a fuel line running
from the fuel manifold or "Y" on the engine, through a restrictor then
back to the fuel tank. I've been told this is to help prevent vapor
lock.
1. Is that the way you guys have set up your fuel system?
2. Should this return line go to the wing tanks or to the header tank?
thanks for your help,
Clem Wehner
KFIV- 912, # 1461 (24 years building and almost done)
Lawton, OK
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 912 fuel return line |
On 2/24/2016 6:17 PM, clemwehner@sbcglobal.net wrote:
> 1. Is that the way you guys have set up your fuel system?
No. I ignored it. Most Kitfoxes do.
> 2. Should this return line go to the wing tanks or to the header tank?
I think it's supposed to go to a place with minimal back pressure, thus
the wing tank.
Guy Buchanan
Ramona, CA
Kitfox IV-1200 / 912-S / Warp 3cs / 500 hrs. flying again.
Now a glider pilot, too.
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|