I have an OS 45 F.  It was an older RC engine.  I plan to use it on a 55 ounce plane.  I'm not looking for a 2-4-2 type of break.  Any suggestions on a prop would be welcome.

I have an OS 45 F.  It was an older RC engine.  I plan to use it on a 55 ounce plane.  I'm not looking for a 2-4-2 type of break.  Any suggestions on a prop would be welcome.

You might be talking about the OS 45 FSR. A really nice engine from the 70's and that series was in my opinion the zenith of OS engine technology. I have a 45 and just rebuilt it with a Bowman ring. Very good runner. Now for the bad news. I can't help you with any info for it's use in C/L. It was never converted over.I ran 11/5 on it R/C. You probably could go up to a 12C/L depending on the aircraft.
Interesting tidbit, the 45 cost $20.00 more at the time of it's introduction over the 40. A lot more 40's were sold then the 45. Guess $20.00 was at the time a deal breaker

I have an OS 45 F.  It was an older RC engine.  I plan to use it on a 55 ounce plane.  I'm not looking for a 2-4-2 type of break.  Any suggestions on a prop would be welcome.

Hi

If it is a 45 FSR  try a 270 restrictor witha .157 spray bar thru it, use a 12 x 4.5 prop. make sure it has a good ring fit and good bearing. If it is setup Ok it will run a nice hi RPM 4-2

Regards
Randy