Os 40la
 

15% Wildcat
12x6 APC prop <---(Typo is actually 10x6)
apx 250ft above sea level
stock muffler with rubber deflector pipe
apx 30-40 flights

11,400 RPM run at 11K

Runs about 200 - 400 RPM slower with a Master airscrew. 5% Nitro cuts RPM down to the low 10's and runs high 9's (Sounds like quarter mile times.)

Os 40la
 

Anyone know the RPM of .46 LA with an 11x6 MA prop??

Os 40la
 

Are you sure this is correct?
My OS .50sx turns the APC 12X6 at 10500 when tuned for flight.
Probably a couple of hundred more max. (10%nitro)

I have also read that the Irvine .53 turns the same prop at 10700.

Os 40la
 

I flew an OS46La today with a 12x6 at 9900 rpm. Could be better, but the last time i adjusted the carburater is 2 month's ago.

Vincent

Os 40la
 

Sorry guys, typo. my props are 10x6 not 12x6 as earlier stated. :stupid:

RE: Os 40la
 

I got9800 with an APC 11x6, 10% Cool Power, 70F, 65%RH. That was the 2 tanks on the break-in runs though. Got about 10400 leaned out to almost max. Too much prop for it. I haven't run it with the 10X5 APC or the 10X6 MA's I'll fly it with. Ididn't have them at the time

RE: Os 40la
 

OS 40 LA
MAS 10x6
Morgan Fuel Omega 15%
17% oil 30/70 castor/synthetic
OS 8 plug
38 deg F, dew point 18 deg F, density altitude approx 750' below sea level
Stock muffler, no baffle, long (~3') rubber hose extension (to keep the neighbors happy)
Mildly ported sleeve

12,900rpm tuned for flight (3 clicks rich, probably -300 rpm)

I'll try to post the numbers with no extension and peaked when I get a chance.

RE: Os 40la
 

http://www.rcuniverse.com/forum/m_3437700/tm.htm

RE: Os 40la
 

750 ft BELOW sea level??? Atlantis???:D

RE: Os 40la
 

40 fp 0% nitro 16% castor turning a 12x4 10500ish rpm

RE: Os 40la
 

OS 40FP

APC 12.25x3.75 @ 10400 peaked.

APC 10x6 12000 peaked.

Byron's 10% fuel. 30°F or so barometer 30.12".

This engine may be slightly modified. I received it 3rd hand and runs better than any other FP I have run. It is an old iron sleeve engine. I just ran it on the stand to see if it was strong enough to go on my Modeltech Magic Extra 300l and then found this thread...I guess I am going to give it a try. The K&B 61 Twister I was going to use won't fit in the Magic Extra fuselage.