Can I use a motorcycle engine in my boat?

I have a 16' fiberglass speed boat hull that I want to convert to a inboard. I've read all the reasons why I shouldn't (thanks), I still want to convert it. I want it to look interesting and different. I believe a V-8 and V-6 both would wiegh too much. I would like to use something like a 1100 cc Shaft driven motorcycle engine. My question is, can it work? What are the reasons why you think it can or can't? Water-cooled or air? Thanks for all the input. Mike

Re: Can I use a motorcycle engine in my boat?

What does the hull weigh with the power package? What is the horsepower of the engine?

Re: Can I use a motorcycle engine in my boat?

FastBoatBronson said:

I have a 16' fiberglass speed boat hull that I want to convert to a inboard. I've read all the reasons why I shouldn't (thanks), I still want to convert it. I want it to look interesting and different. I believe a V-8 and V-6 both would wiegh too much. I would like to use something like a 1100 cc Shaft driven motorcycle engine. My question is, can it work? What are the reasons why you think it can or can't? Water-cooled or air? Thanks for all the input. Mike

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you can make anything work, how well is just a matter of your ingenuity.

Re: Can I use a motorcycle engine in my boat?

a motorbike engine just won't make the low end torque needed to move a boat. HP ratings are nothing more than a marketing game... its all about the torque baby.
my last bike was a Triumph TT 600cc. It was 110hp to the wheel.... sounds nice right... but only 45ft lbs of tq or something like that.
Even a big twin motorbike engine would be the equivelent of a 50-75hp outboard on the back of that thing.

Re: Can I use a motorcycle engine in my boat?

Moving this to the Boat Restoration and Building forum. It's more like rebuilding and building a boat than anything else.

Re: Can I use a motorcycle engine in my boat?

Hayabusa engines are used fairly often in small cars / large go-karts and seem to work fairly well.
Of course, this still isn't the constant high load that a boat will demand, so I'd be very diligent about cooling and monitoring the temp.
I'd definitely vote for liquid cooling, it may be easiest to just reuse the bike radiator and fan, but it would be a cleaner install to replace the radiator with a water/water intercooler and pump, so you can use raw water to cool the bike system.
A 'busa wouldn't have shaft drive though... maybe a u-joint in the prop shaft to level it out a bit, then a double width chain to couple to the existing countershaft sprocket? This would leave the engine sitting sideways in the boat, which isn't exactly the best looking solution, but it would be fairly close to centered, which a shaft drive wouldn't be.

Never thought of putting a bike engine in a boat, but I've had plenty of daydreams about a sportbike engine in a small roadster, something like the Ariel Atom.
It's not too hard to find wrecked sportbikes with low miles either, engine is usually fine, with thousands of dollars damage to the plastics and frame.

Another engine that may actually fit your needs better is an old Goldwing, GL1000 or so. Horizontally opposed four with shaft drive, so it would center up pretty well in the boat. A lot less power (and more weight) than the Hayabusa though, and I was presuming that performance is a fairly high priority.

Re: Can I use a motorcycle engine in my boat?

Heck you can put an Allison V12 in a boat in fact its been done . That however doesnt mean its a good idea although the Allison will have enough torque to flip the boat over if you can get it to hook up .


Rick

Re: Can I use a motorcycle engine in my boat?

how about a jet ski engine instead with the jet inboard. Look on u-tube some guy did it and it was fast as heck..

Re: Can I use a motorcycle engine in my boat?

What was the original HP of the OB that it had on it or what is the boat's max HP rating??

What kinda shape (integrity wise) is your hull?? May not be able to handle a strong 50 horse if the transom is shot

There are plenty of go fast boats out there to buy turn key..For the cost of even a salvaged busa motor..you can really trick out an OB..

And I guess the other question is how fast do you really wanna go?

Re: Can I use a motorcycle engine in my boat?

100hp 45ft torque....

HP= Torque*rpm/5252

HP ratings are derived from torque measurement

question is where/when the peak occurs.

Re: Can I use a motorcycle engine in my boat?

Just happened across this while looking at something else on youtube...
Hayabusa powered, surface drive, offshore boat: http://www.youtube.com/watch?v=gUTugwF2MY8

I like the surface drive idea, firstly it looks cool.
Secondly, it doesn't require as much driveline angle, so you probably could just tilt the motor over a bit, without any u-joints or anything.

Re: Can I use a motorcycle engine in my boat?

I would think it would be rather easy if you get a shaft drive engine. Like the previuos poster mentioned, the torque would be the limiting factor. Motorcycles can over come this through gearing. You would have to adapt the tranny, not enough torque for direct drive. Heck mount the whole bike in the back of the boat. You could sit on the bike and shift gears. Steering would need to be adapted.

Re: Can I use a motorcycle engine in my boat?

Very cool idea. A big v-twin would have the torque you needed. You could get a six cylinder off a valkyrie and that would be plenty of motor. I've seen them pop willies on that beast. I have a kawasaki vulcan 1600 and I believe its rated at 90 ft lbs of torque and about 60 horses so I think that would be enough. A motorcycle engine is also made to be run at higher revs for a longer period of time than a car engine. Be cool to see.

Re: Can I use a motorcycle engine in my boat?

Rickairmedic said:

Heck you can put an Allison V12 in a boat in fact its been done . That however doesnt mean its a good idea although the Allison will have enough torque to flip the boat over if you can get it to hook up .


Rick

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That Allison V12 is how Hydroplanes got the name ThunderBoats, Just had a few running in SeaFair on Lk. Washington yesterday! And boy do they flip
Also the Merlin/RollsRoyce

Re: Can I use a motorcycle engine in my boat?

Lion hunter said:

I would think it would be rather easy if you get a shaft drive engine. Like the previuos poster mentioned, the torque would be the limiting factor. Motorcycles can over come this through gearing. You would have to adapt the tranny, not enough torque for direct drive. Heck mount the whole bike in the back of the boat. You could sit on the bike and shift gears. Steering would need to be adapted.

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I'm about 90% sure they did exactly that on Junkyard Wars a few years back.

Re: Can I use a motorcycle engine in my boat?

It would have to be water cooled. The motor would be to enclosed for an air cooled. Aircooled can only handle about 10 minutes of running with no air passing over them. Goods luck and keep us posted

Re: Can I use a motorcycle engine in my boat?

The biggest issue I see is the transmission. Can't have a multi-gear transmission on a boat (though I think there may be very few that are starting to working with some sort of 'multi-gear' or 'variable gear' automatic arrangement). In a car or on a bike, the wheels still turn at full speed , and you still roll at the same speed when you hit the clutch to change gears. If you had a transmission on a boat, as soon as you hit the clutch the prop would REALLY slow down, and the boat starts to slow instantly, so I suspect by the time you get to the 'next gear' you may have slowed down to the point that you need to go back to the gear you just came from.
Years ago it was not totally uncommon for some commercial guys to use car & truck engines with manual transmissions (right out of the wrecking yard) & drop them in their commercial fishing boats. No marine conversion at all, dry manifolds w/ straight stacks. They would not use the clutch at all, forward was just a fast slam into second gear (pretty much a 1:1 ratio), and reverse was reverse (real slow due to the high gear ratio of the atomotive reverse ratio). The setup would last a year or so & when it died they would pull it out & make another trip to the wrecking yard.