Twin engine scooter

17 posts in this topic

Posted

If one is good two is better. I know this may have been done before but my plan is to build and document everything that comes along with doing this. A few things to note from the get go.

I plan to use this on the street on my scoot once I have tested and validated the results (to MY expectation and standard)

I know I can buy a multiple cylinder engine that is designed and built to do this that will perform much better, I am not concerned with that.

This is about having fun, learning, exploring combinations, performance increase, etc.

I plan to run the engines using various phasing to see and learn what is optimal.

My overall hope is to have a setup that can have the engines failry stock and not heavily modified (who am I kidding) to get a substantial increase in power and run 100mph comfortably. I think this is easily attainable.

My thought is the less modified (Hand modification) there is the less variance the engines will have. So if I buy off the shelf performance parts and build the engines I should be close (it won't be close but its a good start)

HOW: cut the case off, build an engine support, use a chain drive to link the engines, crank to crank. Machine a crank extension on the variator side of the existing engine to accept a sprocket and install an additional bearing support for this extension. Install a chain tensioner to control play.

I will use old CPI engines I have laying around to do testing.

 

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Posted

I'm in, the way scooter motors and drives are this should be interesting for sure, build it and they will come hahaha

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Posted

or put an electric hub motor in the front ...

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Posted

I believe a trike would be easier to build with two engines.

Is it possible to run a GY6 engine upside down?, that would make things a lot easier. 

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Posted

Probable not up side down as they are a wet sump motor, but a icebear trike with a motor for each back wheel might be interesting.

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Posted

Can't wait!

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Posted

or put an electric hub motor in the front ...

MJS I was actually playing to try out a BLDC as an electric "supercharger", but the cost is very high where I am and batteries will cost a good bit. I was thinking to gear it to the crank for torque to help the engine get into its powerband. Unless I can get at least a 

The plan is to put the second engine in the space between the current engine and front upright. I'll also be fabricating bracing to triangulate the frame for added rigidity.

I believe a trike would be easier to build with two engines.

Is it possible to run a GY6 engine upside down?, that would make things a lot easier. 

The plan is to put the second engine in the space between the current engine and front upright. I'll also be fabricating bracing to triangulate the frame for added rigidity. 

I've spent some time on a dry sump idea but it is a lot easier to just place the engine right side up. It will take a lot of welding, drilling, tapping and time to do it, but it is possible. I've even thought to redirect the oil passage from through the cylinder so we can run larger BBKs but again time and money. 

I'll take some measurements and do up some sketches and plans for you all by Monday (I upload off of my pc at work)

Thank you guys for the support

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Posted

I recall following a Bonneville racers build of a two engined (Honda 500s)  bike, but don't remember the link. BUT, how are these?

 

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Posted (edited)

Second and third wouldn't play. Try this link to see his twin 90cc (SS180) engines.

Edited by minimac

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Posted

love his small V twin!

Seems like a lot of work though.

Might be cheaper to find an old Harley motor to fit in there... :P

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Posted

Maybe, but it would leak oil and leave you on the side of the road!

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Posted

These are awesome minimac.

They entail a lot of welding and machining that most of us may not have the machinery to do. I would like to attempt something as clean as that someday though. 

With the idea I have everyone should be able to duplicate it if they wanted and should only require a few machined parts that they can get done at a machine shop.

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Posted

The SS 180 is georgous. I would ride that for sure even the sound was cool.

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Posted

IIRC he works out of a small 20x14 shop.

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Posted

This looks like a very cool project bcy.. I wish you success.

This is cerca 1979 IDBA national at dragnet 42 in Ohio. twin KZ1000's I don't remember how they were connected.

 

IMG_0792.jpg

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Posted

Looks like the beginning to pro stock hahaha cool what guys use to build, I've seen a couple of in line Triumph 750 s but that was many years ago in Van.

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Posted

Name to two future Pro-Stock gods here  in the picture ate the same national.

 

 

IMG_0794.jpg

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