SJN

Hi guys.

I just recieved my first 91 engine.
I bought the new Webra 91 P5 Acro.
Im going to install into my UK Aerotek Phantom.
Which prop would you guys think I should buy to get the optimum speed.
I know that I must find the best one myself when flying the plane, But I need somewhere to start. These "big" props cost quite alot more than the ones for my Eurotek and that size, so Im not just going to buy a handfull at a time just to test them :-)

The phantom is a bulky plane, so I know it wont be at missle.
The plane weighs around 4,5kg`s

Specs for the engine are:
2000-16000rpm
3,25 HP
590g
recomended props are 14 x 12 - 16 x 8

look for yourself here : http://www.webra-austria.at/1067/data1067.htm

The props seem big compared to the os91 ??













SJ.

Kaos1

Your right, the props are a little larger than what the OS91 typically runs. That is because the Webra that you have has more low end torque. The OS is made to run at high RPM's.

I have the Rossi 91 which I ran in a Bridie Escape. I ran some larger props and a long pipe to keep the sound down. Something in the neighborhood of 13X10 if I remember correctly. the plane weighed in around 5.5 to 6.0Kg but had more wing than the phantom.

The prop you run depends on if you use a stock muffler or tuned pipe. You should start with what they recommend at least to break in the engine. Then feel what type of thrust you have. That would be the best place to start.

Remember to check your ground clearance. Don't think that you will get a 14" prop on there.

Kaos1

SJN

Thanks Kaos1.
Ive ordered a 14x12

Theres just enough room for a 14 prop.


SJ.