Back Bensen B-8 "Gyro-Copter"

Bensen B-8M

Powered autogyro versions of the auto-kites have been developed simultaneously, the first of these being the B-7M which flew for the first time on 6 December 1955. This was followed on 8 July 1957 by the first B-8M (M = motorised) and by the first production B-8M on 9 October 1957. The B-8M is normally powered by a 72hp McCulloch piston engine. Optional features include a 90hp McCulloch engine and a mechanical rotor drive enabling the autogyro to make jump starts. A float version of the B-8M is known as the Hydro-Copter.

K.Munson "Helicopters And Other Rotorcraft Since 1907", 1968

Bensen B-8M

Technical data for B-8M

Engine: 1 x McCulloch Model 4318 pistone engine, rated at 54kW, main rotor diameter: 6.1m, fuselage length: 3.45m, height: 1.19m, take-off weight: 227kg, empty weight: 112kg, max speed: 137km/h, cruising speed: 72km/h, service ceiling: 3810m, range: 161km

Jim Douma, e-mail, 03.02.2018


Ezequias, e-mail, 03.02.2015

how do I buy the design of this gyrocopter ?

adu charles, e-mail, 13.07.2014

I will like to build one of this plans.

Tom, e-mail, 15.09.2013

I have a McCulloch 4318A that I would like to sell. It is complete and ran when put into storage.Make me an offer!

Tonie Wycoff, e-mail, 26.09.2012

I am looking for a Mac engine. Please call at 812-599-7283 if you have one or know where I can get one. THANK YOU

Jan van den Steen, e-mail, 21.07.2012


I would like to know the correct fuel/oil ratio for the mac!
I am using 40 to 1 mix with good chainsaw oil,not outboard,

Jan van den Steen, e-mail, 21.07.2012


I would like to know the correct fuel/oil ratio for the mac!
I am using 40 to 1 mix with good chainsaw oil,not outboard,

shoes, e-mail, 13.06.2011

Mag and prop hub would be good for a start.

GANGADHAR, e-mail, 01.03.2011

its very good

vinay, 28.01.2011

what is the best colour on the back u shape thing yellow is not so good i think blue will be good

bill, e-mail, 30.11.2010

I have a complete 4318a engine in a shipping box , never took it out of box , i bought it to use in a airboat
but everybody it would be stong enough , when I bought it it had gov papers saying it had "0" hour on it an says it has the start up carb on it (?) it is 4 cyl, model 4318a,
spec #0-100-1 what ever that is , I always wanted to start it up but never had the time, it has been in a semi for at least 15 years from a move from fla to al,
I have no idea what it is worth , so if you know anybody
that wants this Mc Culloch engine let me know because i'm ready to sell it asap ,I have a couple of bids on it now but I don't really know what it really worth ,get back to me
Bill loomis 256-449-9216 or

Otavio Araujo, e-mail, 02.03.2010

I live in Brazil, South America [sorry about my english] and I have a Gyro-Copter Bensen with a mcculloch 4318 engine 90 hp. In this moment I am looking for carburator parts & gasoline bumb repair. If anyone can help me, thank you. Otavio

Jonathan Barnard, e-mail, 21.12.2009

I need parts for a McCulloch 4318 engine. Where could i find a coil for the mag or complete mag?

kiran, e-mail, 20.04.2009

will u send me model sketch of your project let me know something about your project please

Jonathan Kuehne, e-mail, 19.04.2009

There is a company in Texas that still supplies many if not all parts for these engines, and may even offer completely rebuilt engines as well. R&D Aeronautical Engineering Co Inc. This guy is out of Caddo Texas 900-527-2006 They have a manual of sorts, and a printed parts list that are well worth having. Also search the net for Skeet Wynans, who flys a Hummelbird behind one of these. There's some pretty good YouTube clips of him at Copperstate

Chris Ivins, e-mail, 12.04.2009

Does anyone know where to find parts for the 4318? or a manual?

Ron, e-mail, 12.02.2009

I need parts for a 4318, 72 hp McCulloch engine. Mag and prop hub would be good for a start.

terry, e-mail, 01.01.2008

i have a mcculloch 4318 engine. having hard time starting. where can i find a service manual,what spark plugs it take? gap setting. find parts. thanks terry

Matthew cody, e-mail, 25.11.2007

I am interested in info on the McCulloch engine, I have one and would like to find a project for it thanks

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