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Author Topic: Good ballpark prop?  (Read 1581 times)

Offline Phil Coopy

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Good ballpark prop?
« on: April 26, 2009, 02:16:06 PM »
I am using a LA46 for the first time ......on my GEE BEE SPORTSTER.......  So what is a good ballpark size to try?

Phil


Offline Tom Weedman

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Re: Good ballpark prop?
« Reply #1 on: April 26, 2009, 02:26:55 PM »
Phil
 A zinger 11-5 APC  11-5 10.5-4.5 RSM 11-6 brodak 11-5 that is A good starting point
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Offline Steve Helmick

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Re: Good ballpark prop?
« Reply #2 on: April 26, 2009, 02:51:17 PM »
The 11.5 x 4 APC is your #1 Baseline prop for the .46LA, tho some prefer the 12.25 x 3.75, possibly clipped down a little.    H^^ Steve
 
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Offline Mark Scarborough

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Re: Good ballpark prop?
« Reply #3 on: April 26, 2009, 06:26:35 PM »
Phil,
My pet prop on the LA 46 is the APC 12.25 x 3.75 in its stock form, I tach my LA46 about 9800 rpm and its a monster with this prop, 10 22 Powermaster fuel, typically about 61 foot lines eye to eye. I fly between Portland at like 200 feet above see leel to Pullman at 2500 feet altitude on 95 degree days with this combo and its proven to be a solid bolt on proposition for me,
For years the rat race had me going around in circles, Now I do it for fun!
EXILED IN PULLMAN WA
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Offline Clayton Berry

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Re: Good ballpark prop?
« Reply #4 on: April 26, 2009, 09:17:32 PM »
Hi, Phil.

Been too long.  Then again, you moved away.

Seriously (for a change).  The 12.25 x 3.75, possibly clipped down a little is the way to go.  Clipped, to give it just a bit more revs, and making the needle range just a bit more easy to deal with.  I did eight or nine flights today, and I only tweaked the needle on the first flight.  And probably didn't need to (was a tad windy, and I leaned it just a bit).  It's a good combination.  My latest is maybe down to 11 7/8?

I do 5 or 10 percent (usually 5) with 23% 50/50 oil.  Brodak stuff.  A fox idle bar plug.  Mine has a standard type venturi that Hal Howard and I cobbled up.  Not the remote set up. An ST nva on a venturi that barely clears the prop arc.  Someone told me that long venturis are good.  Mine work okay.  I'll measure it if you insist.  ID, that is.  Have never played with head shims on this one.  Whatever it came with.  A very good engine.

I tried a couple of wood props - Rev Ups and Zingers, I think.  When the needle was good, all was good.  But the flexibility of the 12.25 x 3.75 is great. 

Hey, results may vary.  But, I like it.  Never bites me, never gets weird.  Briggs and Stratton stuff.  And I'll mention that it has a tongue muffler with more than a few holes in it, that have also been enlarged. 

No idea of how much above sea level I am (I ain't in New Orleans, which is below sea level).  Am currently flying a Twister sort of unit at about 42 ounces.  A Tower 40 has worked well with it, but I had this 46 LA laying around gathering dust...

One of these days I'll come and visit.  Left lane with left blinker on.  60 mph.  Got it.
Clayton - forever busy committing random acts of coolness

Offline Roger Vizioli

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Re: Good ballpark prop?
« Reply #5 on: April 26, 2009, 09:54:01 PM »
Phil,
I also use an APC 12 1/4 x 3 3/4 cut down to 11 7/8".
I flew it on the Blue Cardinal at your Fly In last year.
Roger V.

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Offline Robert W

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Re: Good ballpark prop?
« Reply #6 on: April 27, 2009, 11:27:30 AM »
Hi Phil

Your Gee Bee sure turned out nice, Hope to see it fly sometime. As for props you have been given a lot of good information and you may want to try all of them to see what will work the best on the GB.

I tend to start with a Zinger 12X4 cut down to 11.5X4. This seems to work for my stock motor on the 44 ounce Cardinale. I like to run the motor in more of a constant 2 that picks up some RPMs at the top. Once I get a feel for the prop on the plane I will try others to see if there is any improvements.

Are you running the modified head on your LA46 and will the GB balance tolerate the APC prop without tail weight. If you need the nose weight then one of the recommended APC should be the prop to start with.

Regards
Robert
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Offline Jerry Reider

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Re: Good ballpark prop?
« Reply #7 on: April 28, 2009, 09:13:48 PM »
I am using a LA46 for the first time ......on my GEE BEE SPORTSTER.......  So what is a good ballpark size to try?

Phil



That is one sweet plane.  Is it available in a kit, plans or what.  That would be a great next winter project for me.
« Last Edit: April 29, 2009, 06:44:23 AM by Jerry Reider »
Jerry

Offline Phil Coopy

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Re: Good ballpark prop?
« Reply #8 on: April 29, 2009, 12:39:45 PM »
Robert,

Yes, I am running the modified head so I think  I'll need a little higher pitch than 4.5, but we'll see.  The Balance came bang on with a wooden prop so I think I might have to compensate for the weight of an APC.

Jerry,

I made my own plans and built from scratch.  The wing is a modified Brodak P-40 wing.  If I get time to clean up the originals and the plane flies worth a hoot,  I will make copies available at at cost.  First I think I'll have to get permission from Mr. Brodak if I include the modified wing plan.

Phil



Offline catdaddy

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Re: Good ballpark prop?
« Reply #9 on: April 29, 2009, 02:03:21 PM »
12.25x3.75 cut down to 11.75.
There simply is no better prop for this engine.
regards,
Rick"catdaddy"Blankenship

Offline mike donovan

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Re: Good ballpark prop?
« Reply #10 on: April 29, 2009, 07:28:38 PM »
I have a kit built pathfinder with a stock LA46 and have tried every prop in my inventory. The prop that really works for me on this airplane is the thunder tiger 11X4.5. Other people that I know have found the same thing. Try one, i think you will like it.

Offline Scott Hartford

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Re: Good ballpark prop?
« Reply #11 on: April 29, 2009, 08:39:27 PM »
12.25x3.75 cut down to 11.75.
There simply is no better prop for this engine.
I use this exact thing on an OS 46FX on a profile 3-d plane with a mini-pipe. It howls like a banshee when you wind it up! I will have to try it on a LA. I have been running the Thunder Tiger Cyclone 11x4.5 mostly on LAs and it works good.


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