Bensen air speeds

Earl Shaw

Newbie
Joined
Aug 26, 2009
Messages
40
Location
Innisfil, Ontario
Aircraft
Bensen Mac 72 HP
Total Flight Time
180 fixed wing
Can't find the info I want about Bensens. Please forward what you know. Bensen 72 hp engine.
AIRSPEEDS
NORMAL TAKE-OFF
NORMAL CLIMB
BEST RATE OF CLIMB
BEST ANGLE OF CLIMB
CRUISE
MAX MANEUVERING
BEST GLIDE
NEVER EXCEED
NORMAL APPROACH

PERFORMANCE
TAKE-OFF DISTANCE TO CLEAR 50 FOOT

FUEL AND OIL
FUEL GRADE
MIXTURE FUEL/OIL
USABLE GALLONS OF FUEL
CONSUMPTION PER HOUR
THANKS EARL SHAW [email protected]
 

Gyro28866

David McCutchen
Joined
May 8, 2009
Messages
1,903
Location
Dickson, Tn. USA
Aircraft
Benson B7m & B8m, Dominator II; Kolb Mark III Classic
Total Flight Time
750 combined FW & Gyro
AIRSPEEDS:
NORMAL TAKE-OFF: Don't know , never looked - I was flying. Probably going to be about 25 - 35 IAS.
NORMAL CLIMB: 45 MPH
BEST RATE OF CLIMB: 45 MPH
BEST ANGLE OF CLIMB: 45 mph
CRUISE: 45 - 60 mph
MAX MANEUVERING: 45 mph
BEST GLIDE: 45 mph

NEVER EXCEED: 65 mph, lol
NORMAL APPROACH: 45 mph

Dr. Bensen suggests at 45 mph, the Bensen blades performed at their best.

PERFORMANCE
TAKE-OFF DISTANCE TO CLEAR 50 FOOT: Too many factors to determine. Pre-rotation RPM, winds speed on your 12, thrust of engine, density altitude, etc..
On my Bensen, with a pre-rotate to 100 RRPM, and a 5 mph wind in my 12, 2 - 3 hundred feet to get airborne, get to 45 mph and start climb. robally, 800 - 1000' to clear the obstacle


FUEL AND OIL
FUEL GRADE: 100LL "only", never use auto fuel
MIXTURE FUEL/OIL: 16 oz. petro based 2 cycke oil, 14 oz of Blue Marbles to 5 Gallons 100LL
my CHT was 50 degrees cooler on synthetic and a smoother idle
USABLE GALLONS OF FUEL: "ALL OF IT!!!"
Part 103 - Ultralight = no more than 5 gallons on-board; N numbered "Registered" what ever you can feasibly build into the system
CONSUMPTION PER HOUR : On my ole 72, I could stretch about 65 minutes out of her. On my 90 - "Quiet" in 53 minutes. 5 gallon tank. Depends on power demands.
 
Last edited:

Earl Shaw

Newbie
Joined
Aug 26, 2009
Messages
40
Location
Innisfil, Ontario
Aircraft
Bensen Mac 72 HP
Total Flight Time
180 fixed wing
thanks no wonder all I found was 45 mph the magic number for everything.
Earl Shaw
 

BUD ONEAL

Gold Member
Joined
Nov 2, 2003
Messages
2,202
Location
Ider, Al. 35981
Aircraft
Dominator
Total Flight Time
600+
I was told by many of the "old" men back when I started in 1983 was "just fly and do not get so slow that you cannot" worked for me all these years !
 

WaspAir

Supreme Allied Gyro CFI
Joined
Oct 21, 2006
Messages
4,976
Location
Colorado front range
Aircraft
Bell 47G-3B-1 / A&S 18A / Phoebus C, etc.
Total Flight Time
stopped caring at 1000
thanks no wonder all I found was 45 mph the magic number for everything.
Earl Shaw


It sounds like the flight "envelope" is more of a "postcard". Maybe you could skip the weight of an airspeed indicator and just use a picture of one with the needle at 45 . . .
 

Kevin_Richey

Yamaha gyro...Oregon, USA
Joined
Nov 16, 2003
Messages
2,343
Location
US
It sounds like the flight "envelope" is more of a "postcard". Maybe you could skip the weight of an airspeed indicator and just use a picture of one with the needle at 45 . . .

Ha-Ha-Ha-Ha: Tha is one of the best jokes I've read in some time, Waspair!
 

Gyro28866

David McCutchen
Joined
May 8, 2009
Messages
1,903
Location
Dickson, Tn. USA
Aircraft
Benson B7m & B8m, Dominator II; Kolb Mark III Classic
Total Flight Time
750 combined FW & Gyro
What ya get, when ya fly in the winter!
 

digbar

Gold Supporter
Joined
Mar 5, 2006
Messages
153
Location
Columbus, OH
Aircraft
Challenger II, Sparrow Hawk, Bensen B8-M
Total Flight Time
about 535
Blue Marble is the brand of 2-stroke oil the Bensen afficionados recommend that you mix with the 100LL fuel. I'm go back and read the thread about using high-test unleaded as a means of avoiding lead fouling and buildup in the cylinders.
 

dabkb2

Dave Bacon
Joined
Sep 26, 2005
Messages
2,199
Location
Vista, Ca
Aircraft
2 KB2 90Mac KB3 582
Total Flight Time
289 hours
From what I understand a 72 Mac is about the same as a 503 rotax
 

WaspAir

Supreme Allied Gyro CFI
Joined
Oct 21, 2006
Messages
4,976
Location
Colorado front range
Aircraft
Bell 47G-3B-1 / A&S 18A / Phoebus C, etc.
Total Flight Time
stopped caring at 1000
dabkb2;n1137948 said:
From what I understand a 72 Mac is about the same as a 503 rotax

You can easily tell the difference. If it's running, it's probably the Rotax.
 

dabkb2

Dave Bacon
Joined
Sep 26, 2005
Messages
2,199
Location
Vista, Ca
Aircraft
2 KB2 90Mac KB3 582
Total Flight Time
289 hours
WaspAir;n1137963 said:
You can easily tell the difference. If it's running, it's probably the Rotax.

Ya there is that part, but I thought Earl was just looking for information, not bias gyro bashing.
 
Last edited:

WaspAir

Supreme Allied Gyro CFI
Joined
Oct 21, 2006
Messages
4,976
Location
Colorado front range
Aircraft
Bell 47G-3B-1 / A&S 18A / Phoebus C, etc.
Total Flight Time
stopped caring at 1000
Just a little Mac-attack humor effort, no ill will intended. . .
 

dabkb2

Dave Bacon
Joined
Sep 26, 2005
Messages
2,199
Location
Vista, Ca
Aircraft
2 KB2 90Mac KB3 582
Total Flight Time
289 hours
I know, they have earned it. Have you ever flown a strong 90? When they are on it's an E ticket ride.
 

dabkb2

Dave Bacon
Joined
Sep 26, 2005
Messages
2,199
Location
Vista, Ca
Aircraft
2 KB2 90Mac KB3 582
Total Flight Time
289 hours
cloudhopper;n1138038 said:
I HAVE BEEN USING THE 110 OCTANE RACING FUEL IN MY Mac 90. It is expensive but the Mac loves it.

Sounds good, what size jet are you using and what kind of temps are you getting? I was thinking of going with the 140 octane. That is what my dad use to use and the fuel the Red Bull air racers use, I would have to by a 55 gallon drum.
 
Top