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Superbike engines


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Has anyone given serious thought to using a 1000cc or larger superbike engine? They have the hp:weight problem well under control. They are fuel-injected, and as an example the Yamaha 1000cc engine makes 180hp.

 

Some bike engines require valve adjustments every 2000-4000 miles, so perhaps a larger, less extremely tuned engine would be more suitable.

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I have a friend who's hobby is tweaking his motorcycles and racing on the weekends. I couldn't help but noticing that he had his screws drilled and twisted with safety wire in the same way that aviation engines are done.

 

I think the biggest issue with a motorcycle engine conversion is that I think their power is designed to be delivered at high RPMs (~8,000+?) whereas most propellors need to turn at ~2,700 RPMs. You can get a reduction gear unit (PSRU), as is required for the typical automotive engine conversion, but I'd be concerned about running constant at such high RPMs.

 

There is a company who's selling motorcyle engine conversions for aircraft: www.hog-air.com RPMs are lower, but a PSRU is still required and it doesn't strike me as anything more than a novelty for Harley fans.

Jon Matcho :busy:
Builder & Canard Zone Admin
Now:  Rebuilding Quickie Tri-Q200 N479E
Next:  Resume building a Cozy Mark IV

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  • 2 years later...

I think that you would have problems running a superbike engine at high output for extended time periods. Their horsepower also generally peaks at high RPM of around 8,000 to 12,000 RPM. Superbike engines are really designed for short bursts of high power. They are also designed to rev up very quickly, a feature not really required on an aircraft engine.

Crazy Canuck

Toronto, Ontario, Canada

Cozy MKIV #MK1536

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At times :)

My Concours (1000 cc) has over 150k miles on it, narry a problem. 93HP rear wheel, 108 at the crank... at something like 8000 RPM though. Hi-way cruise at 75MPH is about 4800 RPM.

 

Japanese inline fours typically have the transmission cast as part of the engine. Difficult to adapt a re-drive me thinks.

 

Hardley Riddensom's are a separate engine/tranny (basically), generally need to be punched to get any HP though.

 

The BMW airhead or oil head (horizontally opposed) could be promising, if not for the HP department. Crank is already pointing backwards, thin profile, fair dependability (depending on who you ask), tranny can be removed and a re-drive added if needed, it's already air (or oil) cooled.

 

I don't think a mo-cycle engine would last long in an aircraft though, running basically to the firewall all the time.

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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Some bike engines require valve adjustments every 2000-4000 miles, so perhaps a larger, less extremely tuned engine would be more suitable.

try every 500 for the beamer; pretty bad when a long distance voyager needs to be fussied with at an interval like that.

(not my own experience, what I picked up on the web while looking for a bike)

...Chrissi

CG Products

www.CozyGirrrl.com

Cozy Mk-IV RG 13B Turbo

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try every 500 for the beamer; pretty bad when a long distance voyager needs to be fussied with at an interval like that.

My dad's 900 NEVER gets ANY adjsutments.... so either he's real lucky, or things have gotten much worse on the newer engines. My wife and I borrow the old twin quite often, and the valves tick a little, but they always sound the same. Besides, if the valves were quiet, we wouldn't hear it idling. :) Very nice old bike, VERY little maintenance. Plugs and oil every spring, thats about it (points too, at times).

Andrew Anunson

I work underground and I play in the sky... no problem

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I didn't wanna get in on the bike wars, it's kinda like tin vs fiberglass...;) )

My dad's 900 NEVER gets ANY adjsutments....

Toaster?

BMW's continue to make strong motors. Early ones were somewhat underpowered, relatively speaking, but the cylinders lasted (last) forever. Not uncommon to tear apart a 100k mile oil head and still see the cross hatch hone marks in the cylinders. Bearings and crank are pretty good too.

 

I have no comment about aft of the engine though... on the newer ones anyway :)

 

Rick

Rick Hall; MK-IV plans #1477; cozy.zggtr.org

Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics.
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Toaster?

No, its got the big tank. Fuel economy is not its strong point, so its a good thing. Yeah, its easy to get off the Canard subject matter here. We better be careful too, we don't want to waste all our airplane building funds on some silly 2 wheeled toys, now, DO WE?:cool:

Andrew Anunson

I work underground and I play in the sky... no problem

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