OS 15 LA

Stuka Stunt Main Forum · 19 of 19 known posts recovered

P Walker · Jul 12, 2003 09:40 PM

Does anyone have experience using the OS LA 15? I am looking for a replacement for the OS 15 FP. The replacement needs to 4 cycle better than the FP. So....The real question is: Does the OS 15 LA 4 cycle any better than the OS 15 FP?

I'm sure you know why I might need this information!

P. Walker

P Walker

MontyS · Jul 12, 2003 10:03 PM

#1 source

I do not have any experience with the 15FP but I have been flying a LA15 on the 300in2 stunter. It does not produce much power in a 4-stroke. I launch it at 11,500, and fly it in a solid 2-stroke. I am using a APC 8x4 w/ 5%fuel.
Regards,

MontyS

tools · Jul 12, 2003 10:40 PM

#2 source

Eric Rule (of RSM) has one on the nose of a cute little profile P-51 stunter, you might give him a call. I seem to recall him saying he flies it wound out like an FP though...

Ok, I give up, thinking of mounting 8 on an Northrop flying wing?

Tools

mpa · Jul 14, 2003 10:57 PM

#14 source

FWIW, I have been flying a box-stock TT GP.15 ABC on a 26 ounce Brodak Lightning Streak derivative (approx. 370 square inches). It turns an APC 7-4 prop at 17,000 rpm (with stock muffler and Bru-Line green filter) with 4.7 second lap times on 58 foot (eyelet to eyelet) .015 dia. lines. Fuel is Sig 10/20.
I am working out some engine run and trim issues, but in general I am very pleased. Actually, I am astounded at how well this little plain bearing .15 hauls a plane intended for a .35. Performance should be even better when I get some .012 lines.
For you guys with ARF Flite Streaks, I would definitely consider engines of this genre, including O.S. FP's and LA's.
Derek Moran

Steve Scott · Jul 13, 2003 11:02 AM

#3 source

OK Paul, here is your solution:

Use a single .60 engine, mounted in the fuselage bomb bay and devise driveshaft mechanisms for each individual prop.

No?

Speaking of mulit-engine stunt, the real 9-0-9 is here in MN this weekend. We went over to climb around it and a Liberator on Friday.

One of our club guys built an old Sterling P-38 and was using LA 15s in it. Had problems getting them started reliably but they appeared to run quite well. I don't yet have any LAs.

Howard Rush · Jul 13, 2003 11:53 PM

#4 source

How much do they weigh? I'll get one and stick it on a flying test rig I have for the occasion. Venturi testing can resume, now that the midsummer trek is over. One might also look into modifications for both the LA and FP.

SRiese5283 · Jul 14, 2003 01:14 AM

#5 source

PAUL...They run about the same. LA likes to use more fuel. Same props same fuel, larger head, Works GREAT with the mac's muffler. I would say there close for B-17 work. I would go to the LA-20 but that's a differant issue.

Scott(love to help)Riese

PS going to miss the stunt clinic

Scott Riese

P Walker · Jul 14, 2003 01:58 PM

#9 source

>PAUL...They run about the same. LA likes to use more fuel.
>Same props same fuel, larger head, Works GREAT with the
>mac's muffler. I would say there close for B-17 work. I
>would go to the LA-20 but that's a differant issue.
>
>Scott(love to help)Riese
>
>PS going to miss the stunt clinic

Sorry to hear you'll not be there.

The LA-20 sounds neat. And, it (a B-17 with 4 of them) will be legal when the current rules proposal cycle becomes official!

I might have to try one.

Leonard: Do you know much about these engines? I am looking to get a B-17 running in a full 4 cycle mode! That would sound GREAT!!!

Thanks

Paul

P Walker

catdaddy · Jul 14, 2003 08:56 AM

#8 source

Howard,
The LA 15 weighs 4.87 oz

regards,
Rick "catdaddy" Blankenship

captcurt · Jul 14, 2003 02:31 PM

#11 source

Yes...mods.

Perhaps AAC with timing similar to the AeroTiger?

SRiese5283 · Jul 14, 2003 01:15 AM

#6 source

Does the OS 15 LA 4 cycle any better than the OS 15 FP?

NO....the 20 does

Scott

Scott Riese

The Kiwi · Jul 14, 2003 08:50 AM

RE: OS Max 15 LA#7 source

LAST EDITED ON Jul-14-03 AT 08:51 AM (CDT)

>Does the OS 15 LA 4 cycle any better than the OS 15 FP?
>
>NO....the 20 does
>
When did they add a 20 back to the economy line? (Did they & you are the first to know?) OS does sell some high dollar BB 21's for RC Buggy enthusiasts, but the FP 20's seemingly didn't sell in large numbers, or the LA line might've included a 20 from the start, since the FP 20, I think, was among the first of the FP's to be dropped from production.

.
Kiwi

Circle Burner · Jul 14, 2003 02:25 PM

RE: OS Max 15 LA#10 source

I have a 15 LA in a Flying Clown, the engine puts out a ton of power and is perfect for this plane. But it wants to scream the entire time, which is fun on the Clown.....fast. I have about 7 runs on the engine so I'm hoping that it will be easier to adjust the needle once it is fully broken in. Maybe at that point it will 4 cycle???

Steve Scott · Jul 14, 2003 02:47 PM

RE: OS Max 15 LA#12 source

LAST EDITED ON Jul-14-03 AT 02:47 PM (CDT)

AFAIK there is no and never has been an LA 20 - only the 10, 15, 25, 40 and 46 sizes.

SRiese5283 · Jul 14, 2003 10:31 PM

RE: OS Max 15 LA#13 source

SORRY.....I ment FP-20 lots of them on e-bay NEW

Scott(thanks guy's)Riese

Scott Riese

Randy · Jul 15, 2003 10:29 AM

#15 source

Paul,

Hmm, stuff the boost port?

Randy Powell

DMoon · Jul 15, 2003 11:17 AM

#16 source

LAST EDITED ON Jul-15-03 AT 11:18 AM (CDT)

PW,

I have some experience with an LA 25...There isnt much there in a 4s but on a 2s setup they run really well. I dont know if the little motors are going to have any poopy when they run in the 4s mode.

You could explore 4 OS 26 4s. You could run straight exhaust stacks with no mufflers and get that popping sound. That would be RAD!

Doug Moon

P Walker · Jul 15, 2003 02:23 PM

#17 source

snip
>
>You could explore 4 OS 26 4s. You could run straight
>exhaust stacks with no mufflers and get that popping sound.
>That would be RAD!

That would be GREAT....But....Even with the new rules, 4 * 26 =1.04 = too big. The max will be 0.90.

Now....Maybe 4 .20 4s's!!

P. Walker

P Walker

DMoon · Jul 15, 2003 03:00 PM

#18 source

LAST EDITED ON Jul-15-03 AT 03:01 PM (CDT)

Dont you just hate lmiting rules? I know I do. Limits on motor sizes...makes no sense to me. Pull tests based on weight of the model. If it passes it flys. That makes it all real simple and anything goes. The line length limits the size of the models and the model limits the motor naturally. I dont see how that rule that says .90 is the limit helps in any way. I just dont see it.

By the way the old OS 20 4s, as Brad would say, dont have much poopy.