Looking for answers...

[Bootlegger]

   Hi fellow's, I am lookin for some suggestions on usin a 10 1/2x4 1/2 APC prop on an OS 32.
  Has anybody used one on one of these engines, I have been runnin' a 10x5 APC on them for years but don't want to get "locked in" on just this prop.
  Any help or suggestions sure would be appreciated...
                  Thanks, Gil

[Jerry Tarnofsky]

APC also makes a 9.5 X 4.5 prop. Have one in my flight box. This size may fit the .32 better.
The 10.5 X 4.5 work great on .40 size engines.

Jerry

[Steve Helmick]

Is it a stock OS .32, or tuned up by somebody? If it's reworked, who? That would make a big difference on prop selection. What's the rest of the setup? Muffler? Fuel? Venturi size? Spraybar size? Ok, so I have a lot of questions, but I have no answers at all, except to keep trying props that seem like they might work. If they seem to have potential but are a bit too much load, try clipping the diameter down 1/4" at a time (may be too  much, but you'll learn more quickly if it'll work or not). Usually 1/8" too small won't hurt a lot, but 1/8" too big can bog the engine. Fine tune it later.  Steve

[john e. holliday]

You never know about a prop until you try it.  I have two OS engines that are supposed to be identical.  Of course they are on different airplanes and use differen props.  I also have Fox 40's that will not turn the same prop on the same airplane.  DOC Holliday

[Bootlegger]

     Guy's I thank u for your responses..  Steve the engines are somewhat modified in that the boost port has been blocked and the squish band enlarged to run somewhat slower, they still turn above 11,000 on the tach with 10" props.
   I hadn't thought about trimming the dia in 1/8" increments, will try that after our contest this weekend.
       Thanks again Guy's