I think I found motorcycle engine for an X

TajMan

True Classic
So, for a long time I've had dreams of holding on to one of my X19 bodies, or at least A X19, and building a custom racecar using a motorcycle engine and chain-drive diff. Probably my '79 shell..

I even bought previously, an '07 GSXR suzuki sportbike engine, I had in my head for the longest time that it was a 1000 but it turns out my engine is a 750! So I'm re-selling that now- that's not big enough for car project.

The other day I went to Bikefest out at Miller Motorsports park. Influenced by motorcycle buddies I was talking to, and by the car show they had there and the AMAZING race cars exotics and customs..

#1. - The X will be a track/race car, even thinking about reverse is not an issue at all, not needed for this build. (I'm also building my 77 Lancia Scorpion someday, and that is getting a Mitsubishi 2.3L turbo engine/trans, for a street-car build)

#2. - I'd like to stick to a motorcycle engine, bigger than 1,000cc, and turbo it. If I was going to do a different custom-engine-swap, I'd probably just go with Midwest-Bayless' Honda K20 engine swap kit.

I have a passion for motorcycle-powered lightweight cars, they do it in Europe more, in specific racing classes, and the U.S. has not caught on yet, but I think they will become more prevalent in the next 5-10 years.

Obviously, I have no country loyalty keeping me to the same type of car/engine. Maybe I love the Italian car bodies, and the Japanese engines the most, whatever. I could go for a Ducati engine, but honestly I see that as more expensive in the end and not meant for my goals.

My buddy turned me on to the Yamaha MT-01 engine (1700cc low-rev muscle engine that was in a sportbike frame, not U.S. spec but based off the Warrior XV1700 engine)

[ame="http://www.youtube.com/watch?v=WTnKPIep_yQ"]Yamaha MT-01 Turbo - YouTube[/ame]
[ame="http://www.youtube.com/watch?v=mYcQh3CeKAs"]yamaha MT-01 11 sec Drag Run - YouTube[/ame]

I think turbo, 160/160 HP/TQ would be so fun in an X! And all the power between 1,500 and 5,000 rpm, would be such a different animal than a 14K RPM sportbike engine. And it sounds so great. The fact that its air-cooled could be accommodated for.

Now i really think I'll be deciding between something like this, or a V-twin 1,000-1,200cc sportbike engine..
 
I'm very open to talk and ideas about a racecar build here, I'd love to hear more of X owners opinions. (see you peepin without response)

I was pushing my yellow '86 hard up around a sweeping uphill corner near my house and the U of U stadium here in Salt Lake yesterday. 35mph corner that you can take MUCH faster and its perfectly smooth (my favorite to race my YZ450 Supermoto bike around)
anyway, higher revs and above 45mph enough to bring the rear end out and a bit of drifting in the X. This is in a stock '86 fuel injected 1.5 stock tires and suspension..

It had me thinking about the ideal setup for a track car around the corners..
I LOVE the powerband on the dyno graph, of that turbo MT-01 motorcycle engine. Pretty much the ideal meaty powerband for a 160HP engine that makes its power below 5,000RPM.
But, it had me thinking, is that low RPM Torque so meaty that it would give an X harder-to-control loss of traction situations when on/off throttle around corners?

Maybe what I want really is the less-TQ and massive top-end-power at 14K rpm, from a turbo liter sportbike engine?

I am not an experienced track racer, but I'd love input this is what I dream to build.
 
I assume you have a good working understanding

Maybe what I want really is the less-TQ and massive top-end-power at 14K rpm, from a turbo liter sportbike engine?

Of the relationship between HP and TQ?

If not then understand that TQ is the twisting force that overcomes inertia. In other words, TQ is what gets the car moving from a dead stop. A peaky sportbike engine is not going to do a good job of that and I suspect you will burn up a bunch of clutches trying to get a vehicle 5 times the design weight moving off the line. 0-60 acceleration times are going to be abominable. This might be appropriate for a land speed racer but is not going to be a fun car to drive on the street.

If you are intent on a bike engine to power your X, then you need to stick to the relatively low RPM, lower HP, higher TQ motors. HP numbers are somewhat meaningless, HP is simply a calculated number based on TQ and RPM. Choose based on TQ, not HP. You can convert some HP to TQ by final gearing, but I think there is pretty limited room to play there.

One way to think about the difference between HP and TQ is to consider a sportbike engine vs a diesel engine. The sportbike engine can rev to 14k and may produce good HP up there, but TQ across the board is going to be fairly minimal. A sportbike engine will not move my F350 and a 3-ton trailer off the line. A diesel engine with the same HP number, otoh, only revs to 3-4k. But 600 lb/ft of TQ? Yes. That will get that giant truck and trailer off the line. I say this because the X is small and agile, yes, but not particularly light.

Overall, the idea of a bike engine in a X really only makes sense to me if the weight of the X can be brought down substantially. Like, cut in half... which means tube frame body, bike engine, fiberglass body, and not much else. Only then will the vehicle be light enough to respond to the limited HP/TQ of a bike engine. If you intend on keeping the vehicle streetable (wipers, heater, radio, full interior, etc) then I don't see much sense in ragging a bike engine to its limit to carry the heavy load, it makes far better sense to me to accept the slight weight penalty and go with a car drivetrain (that has reverse).

Either way it's going to be huge fabrication.

Pete
 
Bike engines are common in 1,000 lb race cars. Once the weight goes up the bike engine has a serious problem. It is not about HP, it is about it's ability to move a x1/9 chassis that is typically over twice the weight of a race car chassis. While the high revving engines can make up the difference using gearing, there will be gear system harmonics that can destroy the gears and all related. Without a gear and drive system specifically designed from SCRATCH for a specific high rpm bike engine, this idea is not gonna work.

Not too long ago, LeMons race buddy who is also chassis engineer for Mazda USA, Dave Coleman tried to build a 'Busa powered Miata. A lot of work and resources went into this project only to have it grenade several times on the dyno.

http://www.motoiq.com/MagazineArtic...sa--Part-1-What-The-Hell-Are-We-Thinking.aspx

If you want a FAST x1/9 by increasing power, IMO the best choice for now is the Honda K20. It works and has been accepted by the racing community as a reasonable race-able engine and there is a good number of aftermarket racer parts for it.

This engine is capable of producing more power for more hours at these power levels than a Bike engine.



Bernice
 
Last edited:
It's a fun little project.

DD or racer are much different apps, I don't think I would motorcycle engine a daily driver, but I would consider it for a streetable hill climber or Lemons / Chump car setup. That is primarly for weight reasons though, as by going the racer route you can cut weight, and in a non DD you can REALLY cut weight.

Some things to consider:
1) what fits... remember that the distance between the output sprocket and the front of the headers (they exit forward) on I4 sportbike engines is longer than the current X1/9 setup, so you will need to move engine into spare tire well / fuel tank area to give enough room

2) what transmission: Assuming you want IRS, there are vendors which can provide options such as quaife. A common "custom" arrangement is a sprocket riding on a differential supported by pillow block or other type bearings. Google "radical racer" images for inspiration.

3) reverse: Goes with 2.. can also be done with a starter motor and sprocket which connects to the wheels only when you want reverse (hit a switch for reverse). Quaife makes a unit with reverse but it ain't cheap

4) What Bernice said about harmonics and the application: I firmly believe that most of the problems that the MIata or other conversions have is they dont retain the "cush drive" (or improve the design a better soft coupling) between the motorcycle transmission and the wheels. All sportbikes use rubber pucks in the back wheel to cushion driveline lash. It's torque pulses that really harm the gears IMO, so you need to buffer the gears from the wheels to dampen vibrations. don't forget using a chain (which has some give) along with a cush drive really smooths out on/off throttle jerkiness.

5) getting going.. there is very little intertia (flywheel mass) and low torque. The larger the car the more you need to rev and slip the clutch. Luckily they are oil bathed so dont burn. nevertheless... something to think about... NOT fun to drive in traffic. Once going like in a race car it doesn't matter.

I firmly believe that it's doable relatively cheaply. I've seen a 1300CC Busa in a Radical race car on slicks run several races with zero transmission problems. It used a quaife drive. I've seen 1000cc models run chains with no issues. There are some x1/9 hill climbers that run great but I"ve never seen engine compartment pics.

I have drafted a design (not past conceptual) that uses the chain drive and a rear motorcycle wheel hub with the spokes cut off bolted to a differential via the brake rotor attachments (and a through-axle), with welded CV adapters riding on pillow blocks.. but I digress

Motorcycle engines have much more in common with F1 and racing engines than street engines. With a good clutch and consistant cooling along with some oiling mods (maybe a dry sump) they can run all day.

I've raced bikes and 10 years ago did a ton of track days on my street motorcycle, probably well over 1000 miles at full throttle with nothing but oil changes.. they might not go 100K miles but for a track day or hill climb car they are exceptionally reliable.
 
If you're serious about a project like this call up and discuss with the folks at Taylor Racing:

http://www.taylor-race.com

Drive line design and needs for a 1000 lb race car is not the same as a 2000+ lb road car. What works great on the 1000 lb race car may be a disaster on the 2000+ lb road car.


Bernice
 
Spend some time a read the Moto IQ article Dave Coleman wrote about the 'Busa Miata. Drive line "cush" was not the problem, it has much more to do with the fact that oily bits of finite dimension goes into resonance. This is factual reality and must be considered in the basic design of the oily bits. There is were serious engineering come to reality -vs- back yard garage shop tinkering, which is not going to make it work.

In today's modern world of engineering, precise CAD modeling and more is applied to all designs to a very high level. Mechanical behavior of all the oily bits involved is analyzed in depth and tested to assure the design actually works before it is prototyped and long before it is produced. The days and romantic fantasy of some designer tinkering to get oily bits working is mostly gone.

Have a look at this video of Dallara which is a race consulting company today and how they design and build real race cars. Anything sort of this is really back yard tinkering..it's OK, but realize the realities and limitations of this approach.


https://www.youtube.com/watch?v=FgTRNJ32fWA


Formula SAE is often powered by bike engines..

Bernice

It's a fun little project.


4) What Bernice said about harmonics and the application: I firmly believe that most of the problems that the MIata or other conversions have is they dont retain the "cush drive" (or improve the design a better soft coupling) between the motorcycle transmission and the wheels. All sportbikes use rubber pucks in the back wheel to cushion driveline lash. It's torque pulses that really harm the gears IMO, so you need to buffer the gears from the wheels to dampen vibrations. don't forget using a chain (which has some give) along with a cush drive really smooths out on/off throttle jerkiness.


I firmly believe that it's doable relatively cheaply.
 
Spend some time a read the Moto IQ article Dave Coleman wrote about the 'Busa Miata. Drive line "cush" was not the problem, it has much more to do with the fact that oily bits of finite dimension goes into resonance.

https://www.youtube.com/watch?v=FgTRNJ32fWA


Bernice

:) thanks for link and additional info, I would need much research to formulate a real engineering opinion but this is just internet fun for me at the moment.

If it's down to harmonics, maybe the miata-busa folks were unlucky with the "busa" and should have picked a Kawasaki (which would have randomly different harmonics). Off memory that seemed like more of an adaption of a BUSA as an engine into a miata drivetrain, something we dont need to worry about being mid engine.

I'm interested from an engineering viewpoint in why the engine cares what the car weighs because there's something I find counter-intuitive about that. I would think the engine cares about what the engine see's.. how it's mounted (physically), how the power is given to the driveline and how the driveline in turn responds to that power.. that is impacted by gearing as much as car weight.

If the car is heavier it accelerates slower with the same gearing, meaning every part spends more time at a certain RPM it's way up the scale, but I would never run a car at the same gearing as a bike... a 150 hp busa x1/9 I would run to top out at 120mph (not 200 mph). Gearing the car down would give you the same gear "residence time"... it's all in the gearing which multiplies torque and allows the car to be drivable

:) my .02 to further kick the debate can down the road... If I didn't see those 1300 to 1500 lb Radicals work so well with the exact system above I'd be more skeptical. Wasn't that busa-miata trying to go through an auto xmission with adapter plates marrying the pair? ... totally different deal. If you keep the motorcycle engine isolated and gear it in proportion with the weight it was designed for I can't see the issue (beyond it might be silly to drive and have too many gears to use).
 
There is a guy on YOUTUBE with a bike powered X19 screaming up the hill... Sounds wicked..

Downside of that, car is fairly stripped out, and he is operating at 9K plus RPM all the time.. I admit... I would like to drive it once!

I put this as one of those (WOULD BE AWESOME IF) but when you begin digging into the details, there are other projects where your ROI will be more fruitful... IMO...
 
Running gears are like little hammers pounding on the entire gear system as they run. While helical cut gears apply enough axial load to the gear teeth as they run to significantly reducing gear running noise, the un-loaded gears clatter. This constant hitting of the gears brings out the resonances in the gear system, If the resonances are strong causing the gear shaft and all related to go into resonant modes (shaft flexure under load and resonance) they can fatigue the materials involved resulting in a failure. Proper design of a gear box is complex and not simple as there are many, many factors involved. This occurs regardless of engine used, it can theoretically happen with a electric motor or other rotational device.

HP is the rate which power is delivered, torque is the available twisting force. Gearing can be used to modify or multiply torque from rotational speed. Sounds simple in theory, in the real world, there are many variables. Bike engines are designed to run at high RPM with lower torque output as the total weight of a motorcycle with rider is typically less than a four wheel motor vehicle. Knowing this, the engine and gear box designer will opt for a system that is designed to carry less weight with the scale of parts to suit that design requirement. This means, smaller parts overall. When these smaller parts are forced to produce near or beyond their designed loads, the parts will be over stressed and eventually fail.

One of the more notable LeMons racers is the Bike engine powered Metro-Geo. It is a mid-engine, bike engine powered LeMons car that has many. many design hours put into it with a lot of technically competent folks behind it. It has won the overall once when it was front engine, chain driver bike engine (Jay gave them bonus laps). Since then the bike engine and gear box with roller chain reduction drive proved to be too fragile for endurance racing. There was one LeMons race where they grenaded the engine, they swapped it out and got it running again. In short time the gear box exploded which resulted in this team trying to make one working engine-gearbox with three broken engine-gearboxes.
https://www.youtube.com/watch?v=QfRlVZiyzr4

This LeMons racer got retired due to lack of durability for endurance racing.

Another bike engine powered LeMons racer was Angry Hampster. Honda 600 chassis with a mid-engine conversion using a bike engine-gear box. This one as back by some engineering folks at the local university with a good machine shop to back them. This one never ran properly. When they finally did get the car to run OK, the bike gear box failed with great drama when it shot all the gears out from the bottom of the gear case.. Very messy.
http://www.motoiq.com/MagazineArtic...-II-Holy-Crap-I-drove-it-and-now-Im-deaf.aspx

If the appeal of bike engined cars is the sound, the real world problems of trying to make reliable and fast race car is not so simple. If this was a truly viable route, there would be a lot more road cars converted to race cars using bike engines..

There are a good number of very successful race cars that use bike engines, they work really well due to good engineering, properly chosen parts, much testing and proving these designs in real world racing.



Bernice


:) thanks for link and additional info, I would need much research to formulate a real engineering opinion but this is just internet fun for me at the moment.

If it's down to harmonics, maybe the miata-busa folks were unlucky with the "busa" and should have picked a Kawasaki (which would have randomly different harmonics). Off memory that seemed like more of an adaption of a BUSA as an engine into a miata drivetrain, something we dont need to worry about being mid engine.

I'm interested from an engineering viewpoint in why the engine cares what the car weighs because there's something I find counter-intuitive about that. I would think the engine cares about what the engine see's.. how it's mounted (physically), how the power is given to the driveline and how the driveline in turn responds to that power.. that is impacted by gearing as much as car weight.

If the car is heavier it accelerates slower with the same gearing, meaning every part spends more time at a certain RPM it's way up the scale, but I would never run a car at the same gearing as a bike... a 150 hp busa x1/9 I would run to top out at 120mph (not 200 mph). Gearing the car down would give you the same gear "residence time"... it's all in the gearing which multiplies torque and allows the car to be drivable

:) my .02 to further kick the debate can down the road... If I didn't see those 1300 to 1500 lb Radicals work so well with the exact system above I'd be more skeptical. Wasn't that busa-miata trying to go through an auto xmission with adapter plates marrying the pair? ... totally different deal. If you keep the motorcycle engine isolated and gear it in proportion with the weight it was designed for I can't see the issue (beyond it might be silly to drive and have too many gears to use).
 
Last edited:
Solutions not problems Bernice! ;)

Saying it's too hard because it takes unobtanium analysis doesn't make us feel as good as unscientific internet banter!

Angry hampster: http://www.motoiq.com/MagazineArtic...-II-Holy-Crap-I-drove-it-and-now-Im-deaf.aspx

600CC (lightly built). Used a CV joint off the output shaft of the engine to drive a traditional gearbox. NO Cush. Solid mount (no engine flex) Also: drivers instructed to NOT use clutch (no cushion). Downshift without clutch (I would NEVER do that on a racing motorcycle because you would upset the bike and crash). They frankly had engineered the give out of the drivetrain and instructed the drivers to use it aggressively. It didn't appear to have enough gear reduction.

Geo Metronome: http://jalopnik.com/5094909/hayabus...-take-on-lemons-sneers-at-ghettocharged-miata

Chain drive this time but also solid mounted with no cush drive (drives steel differential directly)

Busa Miata: http://www.motoiq.com/MagazineArtic...sa--Part-1-What-The-Hell-Are-We-Thinking.aspx ...

Calling that a "busa engine" anymore is a stretch, it uses busa pistons in a modified busa block, certainly not a correlation to a chain drive mounting. That is a great example of resonant frequency induced failure but I contend NOT a good example of a busa chain drive x1/9

Chains come in a variety of sizes and types. Motorcycle racers will use a 520 chain because it's light (and less life) but 530 size high strength O-ring chains will last several thousand miles of abuse with just cleaning. using a non-oring chain means constant lubrication (hard on an endurance machine). doing 2 x 7 hour lemons days or hill climbs or just a couple thousand miles a year this isn't a big issue.


So my original theory remains to be proved, but can not be disproved by those examples

Those lemons teams may have spent a lot of time and money working on something cool, but fear they may have missed a key concept of successful implementation
 
give me some time to read through your replies guys :)

I am not naive about all this and have done a lot of research. I know what TQ is. I know that TQ is HP X RPM, give me some credit. I build custom race cars and motorcycles its what I do.

You posted the video I already knew! (under a different name) Except I believe its not a Busa motor, I believe its a GSXR1000 motor even smaller! (165HP stock) Doesn't even sound to be turbocharged.
https://www.youtube.com/watch?v=2v4cOmeaIgo

Its not all about the TQ only, and yes a lot can be workable still with the gearing set up correct (size of sprockets for chain-drive), and yes it will be harder on clutches in the car setup.

Yes this is a race car, not a street car. And I already mentioned reverse is no longer even a thought for me, unneeded in the race car.

My YZ450 motorcycle... was a former '05 AMA supercross race bike which I acquired! It had been converted to supermoto already. It is an '05, so this YZ only has 4 gears! It has a supermoto 'slipper' clutch. These are designed to prevent wheel hop in some situations, and to help with off-the-line from a stop even when geared tall. I found the perfect sprocket combo on my bike, to still allow me 80+mph at the top of 4th wrapped out. My 1st gear is not as tall as it was when the bike was geared to do 120!.. but its still tall so the motor doesn't have a ton of TQ down low to let the bike to wheelie up easily until you're already doing 15-20mph.. The slipper clutch makes the bike workable in 1st gear still. It slips until you're rolling fast enough to really grab firm. I made the bike street legal, its a blast..

edit: I am only minimally humbled, slightly annoyed by some 'unobtanium' type of thoughts, and generally impressed by your guys responses. Smart people. I will talk to the guys at Taylor Racing.

Quaife offers some amazing gearboxes. I wouldn't be opposed to a setup that eliminates most gears in a motorcycle trans for the most 1:1 direct drive feeding into a separate gearbox (or motorcycle engines that were already muscle-engines designed for use with a separate gearbox..)

have you seen this:
http://www.radicalperformanceengines.com/Power-Drive-Gear-Drive-System/
and these 'busa' V8s?:
http://www.radicalperformanceengines.com/Powertec-Macroblock-v8/

yes I am serious about building a racecar based off of bike-engine-technology
 
Last edited:
I re-read the post too tajman... good thread to grab what you want from it and keep going without sweating the rest. . It would be awesome to move it forward.

Perfect is the enemy of done.. even though I am a licensed pro engineer I also run projects and in this case I would rather burn tig rod than my calculator because I believe the the engineering has been largely done. Time may be well spent laying out a high level concept and sourcing parts to get a budget idea.

seeing what others have done gives a great head start and also what not to do.

Also.. dont forget the g forces on a cycle vs a car and how the gearbox and engine needs to sit and be modded to properly oil at high lateral g's. Radical has thought about this too

Quaife equipment is awesome. From what you have said I assume about a 15k budget? 5k engine, 5k drive, 5k misc parts etc. It would be hard to do this with a quaife and professionally for less than 10k
 
400+ Whp as all 1300cc is coming apart each second. This is the Johnny Hotnuts land speed record x1/9..

[ame="http://www.youtube.com/watch?v=c7Cn5K6fHiE"]Jonny Hotnuts Busa power in Land Speed car dyno run - YouTube[/ame]


Key to making any bike powered car work well is low weight. This means making the x1/9 chassis "Superleggera". 1500 pounds can be achieved using the stock engine/gear box, it take as HUGE amount of modifications, fiber class and more to achieve this. The LeMons racer is 1750 lbs with LeMons legal (This is much more stout than a SCCA legal roll cage) cage and fiberglass panels, Mazda Rotary and Porsche gear box.


Bernice
 
400+ Whp as all 1300cc is coming apart each second. This is the Johnny Hotnuts land speed record x1/9..


Bernice

Great link! It can't be just me... I cringe every time I've run my car on a dyno or seen a link like that where it's just screaming!!...

I smell the start of a tube frame silhouette racer x1/9 ;) Nothing like shedding weight the racecar way... just throw out the whole car except the contour:devil:
 
Aussie Racing Cars

Currently watching these guys on the Ipswich circuit in Queensland and read this post. If you go the big bike motor way then weight is your enemy - cut out as much as possible. GRP front and rear clips will be you only option to shed the amount of weight to get to the target mentioned by the above sage advice.


http://www.aussieracingcars.com.au/

http://en.wikipedia.org/wiki/Aussie_Racing_Cars


These guys are a hoot and very entertaining segment prior to the Aussie Supercar V8 series Downunder, basically a tube frame with a Yamaha 1300cc and various GRP bodies. These little pocket rockets scream to 13,400RPM at over 230kph down the iconic Conrod straight at Bathurst. Thats 63.88888 m/s or 143 mph in your measure

Weight 450 kg

Power 125 bhp, 12400 rpm

Drivetrain Yamaha 1200, Integral 5-speed dog engagement, sequential shift


These guys do the diff housings and axles for the little things so look at how they did things. Their items are 'bespoke' race engineering so $$$$$
http://www.raceproducts.net/about/

Long and difficult road you have chosen. To keep you motivated watch this ( I am sure it has been posted on here but I haven't looked at all the links yet as I sit here on the grass)

Manganiello Vincenzo's GSXR 1000 hill climber

http://2nd2nada.net/hill-climbing-a-gsxr-1000-powered-fiat-x19/
http://jalopnik.com/5890529/the-fastest-fiat-youve-ever-seen

I just love the sound that thing makes


Never heard this Fiat run but torque issue solved :eyepop:

http://img.gawkerassets.com/img/17fiu7icr5vv8jpg/original.jpg



Best of luck

Or dream of the Suzuki GSX-R/4 Concept car that appears in Gran Turismo, I just love Hayabusa-powered rocket sleds.
http://www.supercars.net/cars/1784.html

Sandy
 
Back
Top