the Wasp

My Feedback: (1)

so I have an OS Hyper .50 that I will be running on a Wold Models P-40, I have a GMS .47 muffler, the muffler is a bit big, it's just a bit longer and just a bit larger diameter than the stock OS .61 FX muffler (#E-4010), so I feel this combo will work out pretty much the way I want it to, I have a few jugs of 30% to burn in it

too add to all that , on the lathe I have cut down the fins on an older OS .50 SX Heli head (silver head) to use

so what props are/were you using on your OS.50SX plane engines ??, I thought I would start there

thanks guys !!, keep them flying

Jim

Hobbsy

My Feedback: (102)

OS Max 50SX

http://manuals.hobbico.com/osm/50sx-40-46-61-91fx-manual.pdf

11 x 6 to 11 x 10 Sport
12 x 7 to 12 x 9 Aerobatic.

the Wasp

My Feedback: (1)

thanks Dave, I didn't think to check out Scepter

Jim

the Wasp

My Feedback: (1)

Dave, in your Scepter link look at the plastic prop RPM numbers, compare props close to the same size, such as 11X7, 11X8 and 12X6,, the RPM numbers for those props are very interesting, as for the APC props alone in those sizes they are all within 250 RPM, I have not seen numbers that close on any other engine like that, I'm betting that engine's peak torque point is right around 11 grand

Jim

Hobbsy

My Feedback: (102)

I think you're right on. That guy didn't do a torque curve like Clarence Lee usually does.

the Wasp

My Feedback: (1)

too bad they didn't test an APC 11X9, that would be interesting to see compared to the 12X6,

Jim

blw

My Feedback: (3)

The real test is how the prop flies. Static ground tests don't give much information.

the Wasp

My Feedback: (1)

it sure does,, if

A) you know your plane

B) you know what you want from your plane

C) if you know what you want from your prop

D) if you know your engine's performance and what RPM you want to run it at


Jim

restlessrocks

I've been flying an OS 50sx on a hanger 9 twist 40 for several years. This plane has a very thick airfoil and for 3D type flying the APC 13x4W gives me the best results. I also use one of the old Tower Mufflers on it