Fighting Falcon

My Feedback: (9)

Has any one used or have seen used a OS-91VRDF on a prop driven plane?... If so, what prop would you recommend using??.. What RPM readings should I be looking for??.

I have one of these engines and an unbuilt 60 size P51... do you think this combination would work?? After reading some of the posts I got so excited I want to test some radical combination like the ones posted here..

This is the first time I enter this forum even though I am a speed nuts myself... Just did not know you guys had gotten together in this forum... Nice work..

thanks in advance for your help, Jose E

look

You can start with an APC 13x9
or 12x10
Listen to the engine.
Do not kill it,
you have to hear a good RPM.
Succes.
Look.

Kaos1

This engine is made to run in the 20-23K range if I'm not mistaken. Prop it accordingly to get the most horses. I'd stick to the low end. 10X10 would be a good start if your looking for speed. Of course depending on the airframe, you will have to look at how much thrust you need.

Kaos1

Fighting Falcon

My Feedback: (9)

If I get it right.... does it mean that I should use what ever prop it takes to get 23-24K RPM??.... Sounds very reasonable to me!!

Kaos1

No, not quite. Some props will give you the RPM's that you need and will not pull the aircraft. Like everthing, it's a tradeoff. You need the thrust and the speed. If the a/c is dirty you will need more thrust (diameter or rpm). Just listen to the engine, it will tell you what it wants.

Razor-RCU

My Feedback: (50)

My first guess was 10x10 APC also... (Just a guess here tho-)

The OS-91VRDF will run from 20-23K but that is with a 5" fan- If you could get 19K on something like a 10x10... :0

There is a gentleman on here with a 40 sized Mustang and an OS-65DF engine he stated he gets close to 200 MPH, the 91 in a 60 sized ship should = missile!

If I had more room for DB's at our field I would try it in a heart-beat!

Best of luck and keep us posted,
james

r-c-guy

My Feedback: (37)

Hi,
have not used a 91 df, but I fly .77 and .65 ducted fan engines on 55 inch mustangs(stilleto design). Usually use an 11x7 or 8

randy

maverick

My Feedback: (12)

James, what's a DB?

look

DB is the sound.
Allowed in Europe is 82 DB.
If you talk loud you will have around 80 DB.
Sometimes we produce with speed engines 90 to 105 DB.
Regards,
Look.

maverick

My Feedback: (12)

Oh, OK! dB as in decibels. I didn't even think of that. As James said more room for DB's I didn't equate that with sound. I was thinking of room as in physical space.

Fighting Falcon

My Feedback: (9)

THANKS everybody for their input... I'll definitely post whatever results I get...

Regards, Jose E.