Moons LA-46 setup worked great

After getting fed up with windup and other issues with my LA-46 on my Time machine 50, I tried the setup Steve and Doug Moon had reported on here and in SN. I was using a rev-up 12x5w on 5% nitro fuel, and switched to an APC 12.25x3.75 and Powermaster 10/22. I'm going to keep this setup, the plane really honks and the engine seems much happier running the high rpm setup. It sounds a bit like a piped motor now as it runs a 2-2-2 type run, beeping back into a four stroke here and there in level flight and in a clean two stroke in maneuvers. The windup is greatly reduced, and overall line tension, vertical punch and wind penetration seem better than before. For me, at least, this is the setup to stick with on this plane. The old setup will work, but this new setup is just better. Besides, if I ding the prop, I can just go to the hobby store and get another one...

Welcome to the club!

I'm told this is about how the Magnum 53 works. We'll see soon.

Steve,

I am glad it is working for you. As you tell this is where the motor is designed to run so running it there only makes sense.

If you find any tweaks along the way let us know.

Steve,
Did the same thing with my magnum, the LA .46 really likes it.
My groud realease rpm's are 9.6 - 9.7 . Btw have you tried trimming off
the tips of the prop a little? I have not, I'm carrying more weight than
you I think, so I left it alone.
Dave Heinzman

Hey Dave,

I have not tried cutting down the prop yet. The true Moon setup is about 11.75" diameter, but I figured that it is easier to start at full diameter and cut down instead of putting diameter back on. It might be a nano bit overpropped right now, but I only had seven test flights so far, so more time is needed. My ground release RPM was 9800, when you consider the variance in tachs we are probably turning the same rpm. This setup is much more forgiving on the needle, too. Plus, I was a bit tail heavy, so the ounce heavier APC helps there, too. A win win situation. Next I need to pick up a couple more APCs and see if cutting one down is better still.

Steve,

That's good news. Trying different prop setups is a good thing! I am still going to try my Eather 3 blade 10.5 X 4.0 just to see how it works on my LA .46.... that is .... when I ever get something built to use it on!

funny thing is the eather 10.5 X 3.75 seems to be a PERFECT prop for the magnum 36 man it just loves that prop.
The prop started life as a 12.5 X 3.75 but the pa61 was not happy with the eather, so i cut it down to 10.5 and it is great on the magnum.

Steve: I'm glad to hear the setup worked for you. Makes me want to go out and fly my Imitation with LA 46. Man what a combo!!

Aaron,

Rich (Oliver) seems to like the 12.5 3.75 3B on RO Jett .61's and I just happen to have one mounted on mine that's now sitting in the nose of the Intrepid. If it needs trimming to 12.0 I can do that also, but I'm going to try 12.5 first!

>
>funny thing is the eather 10.5 X 3.75 seems to be a PERFECT
>prop for the magnum 36 man it just loves that prop.
>The prop started life as a 12.5 X 3.75 but the pa61 was not
>happy with the eather, so i cut it down to 10.5 and it is
>great on the magnum.

Glad that works, but assuming you are referring to the 12.5-3.75 3-blade, it really works quite well on the PA61 with the right setup. Good enough to win the 2003 NATs, for instance!

>After getting fed up with windup and other issues with my
>LA-46 on my Time machine 50, I tried the setup Steve and
>Doug Moon had reported on here and in SN. I was using a
>rev-up 12x5w on 5% nitro fuel, and switched to an APC
>12.25x3.75 and Powermaster 10/22. I'm going to keep this
>setup, the plane really honks and the engine seems much
>happier running the high rpm setup. It sounds a bit like a
>piped motor now as it runs a 2-2-2 type run, beeping back
>into a four stroke here and there in level flight and in a

Steve Fitton;

What muffler are you using with this setup?

Doug Moon;

Does your LA 46 setup include the stock muffler?

Thanks;

I'm using a Big Art tube muffler on mine. I suspect the factory OS stunt muffler they used to supply with the FP-s motors would work fine, too. Danny Dirt reported on somebody (Scott Riese?) using this prop with the Macs tuned muffler to very great effect a few years ago. BTW the venturi on mine is the stock .285 venturi with an ST nva. 4.5 OZ fuel is giving a runtime of 6:20 or so, but at five second laps it is adequate to finish the pattern with laps to spare.

>I'm using a Big Art tube muffler on mine. I suspect the
>factory OS stunt muffler they used to supply with the FP-s
>motors would work fine, too. Danny Dirt reported on
>somebody (Scott Riese?) using this prop with the Macs tuned

Steve;

Thanks for the info.

Has anyone tried this setup with a tongue or chip type muffler?

V/r

>Has anyone tried this setup with a tongue or chip type
>muffler?

Yes, RSM tongue muffler for the FP-40 as supplied, Buccaneer 740, LA 46 setup per Doug's instructions. I coulda told you guys this was a hot setup a year ago

Steve
I picked up the last 12 1/4 x 3 3/4 prop for you this morning. Rusty said he would order some more. Think the Saito 40 would turn it?
Willis

Thanks Willis!

If the 12.25 is too much for the Saito, the 11.5x4 I've got should be okay. I don't recall if anybody is running a high rpm low pitch four stroke setup that could report on the results.

I've got an APC 13x4 wide blade to try on the DS 60 when I get the TM 60 done.

>I'm using a Big Art tube muffler on mine. I suspect the factory OS >stunt muffler they used to supply with the FP-s motors would work >fine, too. Danny Dirt reported on somebody (Scott Riese?) using this >prop with the Macs tuned muffler to very great effect a few years ago.

Snip...

Scott pioneered the use of MACS mufflers first with an O.S. 40FP. At first I just thought both he and the muffler were weird. Now I only think Scott is weird. For what it's worth, I simply did not take seriously Scott's insistence that the MACS muffler functioned as a pipe. I have since reversed field on this issue, the intriguing possibilities.

Knowing what I now know about at least one size O.S. stock muffler/stock engine combination I would be sorely tempted to try your stock muffler on your 46LA rather than just leave it in the engine drawer. And from what I saw, subsequently wrote about, the MACS muffler simply must be tried on this motor.

I give full credit to Scott for developing what I guess we can begin referring to as "Scott's Tune-Up, versions 40 and 46," the article I wrote based upon his input is still worth referring to. Especially as I made every effort to get all the details correct. No loose ends, at least none to my knowledge.

I do not remember the specific issue of Stunt News. Sorry.

The 12.25 x 3.75 APC is way too much load for the .46LA/Mac's 6650 setup. It will work if you trim it to 11.25/11.5 dia. You gotta get the 10k rpm at launch and be about 1k rich from peaked. Fuel economy is excellent with this setup. If you have a tank capacity problem, the Mac's setup will help a lot.

Last summer, I posted some pictures of Pat Johnston's QED 500 P.40 with the Saito .40. The prop looked to me like a 12.25 x 3.75, with that abrupt angle change on the LE & TE, near the hub. Pat swears it is an 11.5 x 4...which works great on the .46LA/Mac's. Steve

The LA 46 also works very well with the 12 x 4 bolly
it turns it very easy . It runs a very high RPM 4 cycle, going into a two at the tops of manouvers

>
>The LA 46 also works very well with the 12 x 4 bolly
>it turns it very easy . It runs a very high RPM 4 cycle,
>going into a two at the tops of manouvers
>
>Randy

Randy;

What setup are you running, e.g. venturi size, NVA, muffler, fuel, plug, etc?

Bob,

Careful what you ask for. Last time we dealt with a specific combination for a specific application there was a heck of an argument.

Which confuses me, as specificity is sometimes called for.

I am sure you'll get good information.

>Bob,
>
>Careful what you ask for. Last time we dealt with a specific
>combination for a specific application there was a heck of
>an argument.
>
>Which confuses me, as specificity is sometimes called for.

I've noticed that one of the traits of the really good flyers is their attention to details. Fussiness in watching out for the details means elimination of variables. So, when someone like Ted Fancher or Brett Buck or Doug Moon or Randy Smith or Paul Walker or ... (and a bunch of other folks who are proven and well respected) post a setup, I figure they have spent a good bit of time on the details. They are worth asking for. And, that can make all the difference in the world.

My thanks to them for sharing the details.

V/r

>I agree absolutely and completely. But I still wonder why such thinking >didn't dominate during the various "discussions" concerning a known and >proper tune-up for the O.S. 20FP. The items contained in "Do" and "Do >Not Do" lists were nothing more than really important details developed >over a period of years.

>Dan

Dan;

I just tried replying to your message and watched both your message and mine disappear. LCPs (Little Computer People). And, I haven't a clue why. Fortunately, I still have some of your message in the buffer and have quoted it above.

On the FP 20 discussion, the problem was that some folks confused a debate as to why Brett's engine setup worked as it did with the veracity of the fact it works. I've noticed that setup information from Buck, Fancher, Rabe, et al have consistent trademarks - they are reliable and repeatable. When Len posted his comments as to his theory as how Brett's setup works and other ways he thinks it can be reproduced, neither he nor anyone else doubted that the engine ran reliably and consistently as Brett set it up. The problem occured somewhere along the line when someone mistook Len's two stroke theories and thought that the disagreement as to why the engine performed as it did as questioning the veracity of Brett's setup. At that point, the discussion rapidly degenerated into a large urinating contest

Interestingly, the quest for reliability and repeatability seems tied to careful attention to details to reduce variables and inconsistencies. It is probably the most valuable lesson I have gleaned from the really good flyers who take the time to share their setup information. Now, if I could just apply it as consistently as they do it, no doubt I would improve as well...

V/r

>>
>>The LA 46 also works very well with the 12 x 4 bolly
>>it turns it very easy . It runs a very high RPM 4 cycle,
>>going into a two at the tops of manouvers
>>
>>Randy
>
>Randy;
>
>What setup are you running, e.g. venturi size, NVA, muffler,
>fuel, plug, etc?
>
>Bob

Hi Bob

This is with a 12 x 4 Bolly turning just into a 2 cycle on the ground (about 11,000 RPMs) , it will unload and go into a nice four cycle, then 4-2 thru the pattern. Several ways to do this but we used a .275 to .285 venturi with the new OS NVA, 1 extra head gasket and 5% fuel. The fuel and gasket will vary depending on Temperature and air. we use 5% in the cooler months going to 7.5% or 10 in the hot summer. Make sure you have 25% oil with part Synthetic
Ward van Duzer also use this setup on the FP 40 with excellent results on his profile .

Randy had to let the cat out of the bag! For OS LA .46s.
If you are running 11x5, 11x6 Zingers, Top Flight or BY&O props you are having problems with square eights slowing down to much. When the wind comes up, wind up will keep you flying high.
The Bolly 12x4 props cure these & more problems.
If your current set up is ok, bolting on a Bolly 12x4 will "Supercharge your pattern" . It's like putting in 100 practice flights just by bolting on this prop. It will do great things for your pattern.

>
>The LA 46 also works very well with the 12 x 4 bolly
>it turns it very easy . It runs a very high RPM 4 cycle,
>going into a two at the tops of manouvers
>

Sweetest sound in modeling - an 11000 rpm 4-stroke!

Hey Brett,
I'm a *little* worried right now. I am breaking in my Aero Tiger 36, using a Bolly 10-4 according to Randy, and it's taching at 12,000 in a hard 4 stroke on the bench! Seems like a lot!
But it sure does sound tough.
Bill <><

Sweetest sound in modeling - an 11000 rpm 4-stroke!

Brett

Brett,

Is that a four-stroke motor revving to 11K?

Or a two-stroke running in a four-stroke condition at 11K?

Even though I know the answer, just had to ask. It's my day to be ornery. Tomorrow is Larry's day in the barrel. You are on super-secret double probation.

Tom, I'm suprised your arm is still attached, that was the first time I've seen a plane cut across the circle in out of control flight and bang off the end of the lines like that. At least you know your bellcrank was securely mounted. Fentriss is tough for takeoffs since the prevailing wind is usually cross wind to the take off strip. The landing photo of the Time machine shows why we can't take off from the grass. Maybe the Navy will increase the lawn mowing budget....

You'll have to adjust the camera next time to focus on the plane instead of the fat guy in the middle of the circle.(!)

I think my photo skills are about like my flying was.

>Tom, I'm suprised your arm is still attached, that was the
>first time I've seen a plane cut across the circle in out of
>control flight and bang off the end of the lines like that.
>At least you know your bellcrank was securely mounted.
>Fentriss is tough for takeoffs since the prevailing wind is
>usually cross wind to the take off strip. The landing photo
>of the Time machine shows why we can't take off from the
>grass. Maybe the Navy will increase the lawn mowing
>budget....
>
>You'll have to adjust the camera next time to focus on the
>plane instead of the fat guy in the middle of the circle.(!)
>
>Steve

Steve,
There is nothing wrong with being a little drought and famine resistant. Gives one the edge over the skinny guys at the long contests.....

John (nearly drought and famine proof)