Multiple Zenoahs

Scratch/Custom Builds Article...

A monster, powered by 2 tripple cilindered Zenoahs!!!





Some time ago two German modellers, Rolf and Sebastian, had the same idea: How to build a 2-cylinder engine using Zenoah engines?

They met in the basement of Rolf’s home and constructed an easy connection to couple two engines together. The construction is so easy that you don’t even have to strip your engine. And the best thing is: If you don’t want to run a 2-cylinder engine anymore, just remove the connection and you have two single engines….

Here are some pictures:




Here you can see the required parts. The part on the right side is the connector of the two cases. It is fixed on the front of the back engine. After that, the coupling of the cranks must be installed. It is fixed to the crankshaft of the back engine.




The engines are bolted together. The crank coupler is mounted to the flywheel of the first engine. That’s it!



A closer view of the connection.



And this is the complete engine.



A view from the top. Note that the engine is much longer as the complete newly designed 2-cylinder engine from MTC.



Just to see the difference, this is the MTC 2-cylinder Zenoah.








And this will drive you crazy! By using this method it is possible to add more Zenoahs to a multiple cylinder engine! Here you can see two engines with 3 cylinders working in a 92’’ Rotschi cat. There are no props on the market that could be a problem for these monsters. The engines start with the first pull on the starter. Engine mods? Not necessary! You have three ignitions for every rotation of the crank shaft, three! Each cylinder helps the others. RPM of 20,000 are possible.




Biggest prop on the market that is available in left and righ hand rotationt: ABC 3317! Actually the props are bored up to 8mm and are soldered directly to an 8mm prop shaft.

This engine’s only problem is that it is too long. The catamaran does not offer enough space for a better engine mount. The engine is only mounted on the ends, meaning that the middle Zenoah is only mounted between the first and the third engine. So it is only a matter of time before vibrations will kill the engine in the middle.

After Rolf noticed this problem he removed one cylinder on both sides and actually he runs “only” two 2-cylinder-engines in this cat now. But 50.8cc has enough power to turn the ABC 3317 easily. The actual speed is 75 mph! Not bad for a boat that weighs more than 45 pounds!



These are 2 running pics. I took the pics at the meeting on lake Alf, Germany, this summer.



See larger version in Pics/Videos section  


The video file is from early this summer, done by my buddy Joerg. 

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Tropheus replied the topic: #12291 11 years 4 months ago
dkf....I could not disagree with your point more. Rc boating, in all forms power, can be a dangerous hobby with a lot of unknown variables that you never expect to happen, even with the best planning.

See exhibit A

This pic is of a boater that "touched" the spinning prop of his boat inadvertantly at idle in shallow water wearing a boot. DON'T TELL ME THAT IT IS IGNORANT TO NOT UNDERSTAND WHERE HIS BOAT IS BEING RAN OR THE CICUMSTANCES.

Children, dogs, people without an understanding of the dangers spectating can pop up in bad places unexpectedly. And regardless of the price of equipment used, accidents happen. These boats can go out of control, climb a bank and becoming air born missles with little notice.


Exhibit B....

And C
Watch the whole thing
Ozpulse replied the topic: #12290 11 years 4 months ago
Is there any chance of seeing how the crank coupler locks the two together?
Seems to be very similar to what Im doing with the 50cc twins!
Steve Seebold's Avatar
Steve Seebold replied the topic: #3968 13 years 3 months ago
Insurance? It's better to have it and never need it than to need it and not have it. Once you have an accident, it's too late. Even if you're running in open water and someone with his Cigarette boat runs in front of you and you poke a hole in it and it sinks. Have you priced a boat like that lately?

lohring replied the topic: #3960 13 years 3 months ago
Ask IMPBA members about a serious racing incident a few years ago. At that time IMPBA had secondary insurance, so the members homeowner's coverage had to cover the accident first. It is my understanding that every IMPBA member was sued individually. Fortunately, they all didn't need to hire individual lawyers and the lawsuit was settled. Just defending yourself from any accident, no matter who is at fault, will cost thousands of dollars. Your home owners policy probably will cover you. I would check before you need coverage.

Lohring Miller
Scott replied the topic: #3958 13 years 3 months ago
Thus My post on the dynamics of subject at hand.

Alone ... No issues what so ever ;)

Other persons, Property or Animals .... Be very careful and Insured.

It is really that BLACK or WHITE

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