Wankel engines

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sharps45

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We were sitting around the other day and wondered why no one has put a wankel engine in a boat. They have much lighter weight, less size, and more power for their size than regular engines. Why couldn't you put one in a boat?
 
Yepblaze

Yepblaze

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Jun 1, 2001
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Re: Wankel engines

Wankels aren't cheap.

Even with their simplicity of design, what with being a registered design and only allowed to be built with permission (and fees) of the licensed design owner, (Sachs or NSU?), unless they could acheive high sales numbers they couldn't make it.

There was at least one wankel outboard tried.

mac10right.jpg
1967-1977-nsu-ro80-5.jpg


And a wild turbo wankel jetboat
http://www.ulinkx.com/video/592045/wankel_turbo_powered_jet_boat_2
 
JB

JB

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45,907
Re: Wankel engines

OMC experimented with wankels in outboards (as well as snowmobiles) in the 70s.

I tested a 35HP wankel prototype on a Boston Whaler 13. It had poor low end torque and was extremely noisy. I didn't like it at all and told OMC so.
 
Silvertip

Silvertip

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Re: Wankel engines

My neighbor had a Wankel rotary on an Arctic Cat snowmobile and it ran well. Wankels are not particularly economical from a manufacturing standpoint nor are they very economical from a fuel economy standpoint. They can make good power but the crankshaft (actually an output shaft) rotates at three times rotor speed so low end power would seem to be lacking. They are nice neat packages however
 
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sleeper

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Aug 26, 2008
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Re: Wankel engines

Wankel engines can make good horsepower for their size, but all of the mainstream ones (mazda) are very low displacement (1.3L) which means they don't make any torque. An engine that needs to rev into the 7-9k rpm range doesn't seem well suited to a boat. It would be a dog out of the hole, run good on top end, and not last very long due to prolonged super high rpms.
 
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sharps45

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Re: Wankel engines

Great information! We were just wondering, and now we know! thanks again
 
RotaryRacer

RotaryRacer

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Re: Wankel engines

There are a few things in life that I at least want to try. Putting a Wankel in a boat is one of them....actually in a PWC may be more fun.

Atkins Rotary has marine conversion parts for Mazda motors available. You could easily buy all of the parts from them and convert an I/O to rotary power pretty easily. It is more expensive up front when comparing to other more taditional motors.
 
Hogger

Hogger

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Jul 15, 2008
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Re: Wankel engines

That's sweet. Right around 1:28 they show the dash, and if that big middle guage is MPH, he's right at 70 MPH(if it's accurate). Althought it looks alot faster.
 
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endneu913

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Jul 12, 2008
Messages
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Re: Wankel engines

+2 for Atkins, those guys will put a rotary motor in just about anything! Their 2 rotor airplane is pretty darn cool... Dave Atkins in the man to talk to about rotary apps... their shop up here in the Seattle area is usually open business hours to check out too...

The thing to remember, as people stated above, that since a 2 rotor eccentric shaft spins twice as fast as a piston crankshaft, the 1.3 liter 2 rotor is kinda sorta making 2.6 liters of power in the same time.. ( thats what we rotary lovers try to tell ourselves anyway)...hehe... I love my FC!
 
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WizeOne

Commander
Joined
Mar 23, 2008
Messages
2,097
Re: Wankel engines

5150abf said:
We are shut down for a week and half at work so I have ALOT of time to kill, found this on Streetfire.com

http://videos.streetfire.net/video/Ski-boat-with-turboed_175737.htm

Looks pretty fast and sounds pretty good too.

They have video of Miss Geico going 210mph too, yikes.
Click to expand...

Looks like that boat was doing a little bit of chine walking every time he goosed the throttle.

With that high pitched whine, I kept waiting so see a zillion little pieces fly across my screen.:eek:
 
Chinewalker

Chinewalker

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Aug 19, 2001
Messages
8,902
Re: Wankel engines

A friend of mine has one of the old Mac 10 Wankel outboards. He's actually run it at AOMCI meets and I can confirm that it is a bit of a dog and VERY loud...
- Scott
 
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