Prop / breaking in the engine
 

Hi all,

Wich propeler would you suggest for a new OS 46 FX?
I'm in the breaking in stage right now.

I was thinking about using an APC 10x6 or 11x6. Will this be fine for breaking in the engine?

Thanks in advance.
Luis.

Prop / breaking in the engine
 

I've used 10x6's and 11x5's on SF .46's with no problems either should be fine. Just remember to get it up to operating temp quickly.

Prop / breaking in the engine
 

11*6 will be just fine in my opinion

Prop / breaking in the engine
 

I normally run an 11x6 on my 46 FX.

Prop / breaking in the engine
 

Thanks for your answers.

SD13, 11x6 will make the engine to work at less RPMs, right? This should help at the breakin in stage, right?

Crashem, sorry for asking, but.. why is important to get it warm (operating temp) quickly?

Regards,
Luis.

Prop / breaking in the engine
 

The type of engine you have (ABC or ABN) is designed so that the pistion and sleeve are very tight when cold and the sleeve expands somewhat when the engine is running from the heat. Running it too rich which will keep the temperature down can cause execessive wear on the sleeve which when run at the proper temperture will result in a loss of compression which will be noticed as loss of power. You could also damage the chrome or nickle liner plated to the sleeve. Read the instructions and follow them or have someone with experience help you.

Prop / breaking in the engine
 

ok here is a small explanation about the pitch.

excuse my poor english.

for a specific prop size, as less is the pitch as hig is the rpm (and vice versa).
to explain what is the pitch try to imagine your propeler turning in something like mayonaise. a six inches pitch prop will enter the mayonaise 6 inches in one revolution

for a specific pitch, increase the prop diameter will reduce the max rpm (and vice versa)

the basic effect of pitch on flight performance is as follow. the pitch can be compare to the "gear" of a car. a small pitch will give you a hig rpm, the plane top speed will be slightly lower, but the take off run will be shorter and the climb performances better.
A hig pitch prop will give you a faster plane, but take of run will be longer and climb performances reduced.

try to always select your prop to stay in the engine manufactuer RPM recomandation

that's the basics

Prop / breaking in the engine
 

Hey guys,

Thanks for the help!
I think I'll go with 11x6 for now.

Regards.

Prop / breaking in the engine
 

When running in an engine it's best to use a small prop to keep the load down on the conrod bushes. This lets you use a rich enough mixture but still get about the same revs as it'll turn later on when peaked out. The mixture should be set so it's just barely above the point where it switches from 4 stroking to a clean 2 stroke and no leaner.

Prop / breaking in the engine
 

Just how do you brake in an engine. I have a OS .46fx and someone told me not to follow the book that comes with it.
Any thoughts on this?