Rotax 503 on a Bensen?

COPTERS8

Junior Member
Joined
Sep 23, 2004
Messages
3
Location
DEXTER KENTUCKY
Ron My Name Is Doug Turner I Am In The Helicopter Business.. I Have Become Interested In Gyro In The Last Year Or So.. I Just Bought A New Bensen Bm8 Without An Engine.. I Want To Know If A Rotax 503 Would Be Enough Power? Can You Give Me The Name Of Someone That Knows The Bensen.. I Am A 15000 Hour Helicopter Pilot/instructor But I Want To Get Some Dual Before I Try To Fly It.. Can You Give Me The Name Of Someone Near The Western Kentucky Area I Could Fly With..
Thanks
Doug
 
Last edited by a moderator:

joeheli

Senior Member
Joined
Mar 4, 2004
Messages
761
Location
Jacksonville
Aircraft
Bensen B8M with Mac 90
Copter Here were I live, they are some Bensen with 503 Rotax and they fly very well.
 

GyroRon

Former Gyro know it all
Joined
Oct 29, 2003
Messages
16,664
Location
Fort Mill South Carolina
Aircraft
Vans RV4 / Dominator 582 Ultrawhite
Total Flight Time
ALOT
I think that if you keep it very light and simple a DUAL CARB DUAL Ignition 503 with a B box reduction drive and as close to a 2 to 1 ratio as you can get - swinging a 60 inch three blade Warp drive prop.... you will get decent performance. Don't give in to the urge to litter up the gyro with unneeded stuff like lights and extra large fuel tanks and other stuff. Light and simple is the name of the game!

Also would take a serious look at the threads Scott Essex has been posting pics of the rebuild of his Bensen. He has dropped the rear keel - well to be honest it is in the same place and he raised the rest of the machine - A Stock Bensen with a Mac Drone engine is close to centerline thrust - GOOD THING TO HAVE CLT!!! - but with the Rotax and big 60 inch prop, if you don't " drop the keel " you will end up with a gyro with a high thrustline - BAD THING, CAN KILL YOU!!! HTL -
 
Joined
Mar 22, 2004
Messages
32
Location
Climax, NY
Aircraft
Bensen B8M N54Z, Gyrobee, Dominator under construction
Total Flight Time
1500 hr tailwheel, 300 gyro
Doug
I am flying a complete stock Bensen with a 503 with dual carbs 2.58:1 gearbox and a 60" Warp Drive prop and have been doing it for a number of years. My weight is around 210 and our airport is 800" above sea level. If I get rid of the stock Bensen blade and tail I think I could do better. If your building just keep it light.

Frank Zarzycki
 

scottessex

Sling-Wing Pilot
Joined
Nov 12, 2003
Messages
11,172
Location
central, ga
Aircraft
Dominator 582
Total Flight Time
200+
Or you could go with a VW like John Stevens did, then you can still use the small prop.

If you go with a 503 and a 60 inch prop your mast will have to be taller, and you should raise the seat the same amount as the engine.
 
Top