Our WR426 had a kick start, we fitted some italian electric-start kit. The quality of the kit was marginal. The 450 has electric start so that shouldn't be a problem.

Ducati monsters are 90deg twins!! Not singles.

quote:

Originally posted by jonno:
I don't really like the idea of air cooled engines... whilst they are basic and increase the simplicity of things, I can't see without impressive ducting (or with the single head tilted out to one side) how you can get a good airflow behind the drivers seat. Teams do run them, so they do get them working though. any teams run an aircooled?

Most performance "air cooled" engines are really oil cooled. They've got a wee oil cooler. It seems like you could have a more efficient system overall, since the oil can be hotter than water, and hence lose more heat.

so for the single cyls oil cooling is well important. i heard the bikes run the oil round the inside of the frame to dissipate the heat.

where can i found out how much heat needs losing from the oil? does the enigne have a thermostat for the oil?! would it be possible to fit one? What are the dangers of the oil being too hot or cold?
any ideas?


dan

The wr450 uses the frame at the front as it's oil storage, it is the portion of the frame that runs up from the lower front engine mount up to the steering pivot, a long tall column basically. either side of this in front of the bike riders knees are the two water radiators, so it's obviously where yamaha believe to be best for airflow over it.
For our install on the car we are running with the oil tank off the yzf450 quad (basically the same engine): we're intending on rejecting all heat by the water cooling system... the oil tank is partially in the airstrea though so will be cooled. It's all logged on the dyno though so any problems will instantly flag up over the next few days

quote:

Originally posted by danzim:
so for the single cyls oil cooling is well important. i heard the bikes run the oil round the inside of the frame to dissipate the heat.

where can i found out how much heat needs losing from the oil? does the enigne have a thermostat for the oil?! would it be possible to fit one? What are the dangers of the oil being too hot or cold?
any ideas?


dan

Engines start with the oil cold, and unless you're doing something crazy it won't be too cold.

They make oil thermostats, I've used one for a temp gauge for air cooled VW's.

about singles,

jawa engines have no transmission and make most of their power because of the methanol.

the 450s yamaha and honda, there are kits to make them 505 for AMA dirttrack racing but i know that the honda can be a 530 because the quad engine has an availible big bore kit. there is also a crank available that would make a stock motor into a 505, add this to the 530 kit and you are into the 600 range.

the honda CRF engine/trans is absolutely a terrific motor except the intake valves are hard coated Ti and as soon as you wear off the coating bye bye intake valves.

the yamaha is equally potent but i know less about them.

stay away from cannondales! i worked for a company that bought out cannondale ,,, junk...
eventhough they have fuel injection.

I have heard power ratings of singles stock over and over, but does anyone know the power of a FSAE restricted single? What does the torque curve look like?

I just don’t see how the power to weight ratio of a single would be superior to a 4 banger.

I make 38 HP with a 2002 Suzuki LTZ400 - I wouldn't really recomend a single, starting can be diffcult, they can kick back an blow your starter clutch, and they make way more noise than a 600/4.

Also since the 600's are designed to take 100+ HP they can the clutch and tranny/rods can take 75HP all year with no probs.

Howeve my engine was designed with 32 stock and I'm up around 40 HP now, things break/bend/wear out faster - I go through clutches all the time.

I dont know how those formula student guys ran the acceleration so fast...

Bruce
http://engsoc.queensu.ca/formulacar/engine/

quote:

I dont know how those formula student guys ran the acceleration so fast...

acceleration isn't only about HP

What teams have been sucessfull with singles?

Royal Melbourne Institute of Technology (RMIT) won Student with a single.

Cheers

Ben Inkster
UWA Motorsport
University of Western Australia

IMO you should lose 50 points for terrible sounds whilst using a single

Everybody's got an opinion Frank!

RMIT produce roughly 60hp rear wheel. Not only have them won FS, but they also come second in FSAE-A 2004.

Remember, there's no right or wrong, just different!

Delft and Tokyo Denki were doing very well with their singles at the Formula Student event. Delft was actually first in points before a wiring problem ended the endurance.
And if Delft can do a 4.12 second acceleration with a single it's hard to argue there isn't enough power.

Igor
ps next week you can watch our new Spyker at Sebring :-)

Come on guys, you all know its got nothing to do with power by itself, its a power to weight thing. you have to look at the whole package, we built a 169kg car with a 60hp single.......you do the maths. not to mention the increased drivability of a single!

ash

quote:

Originally posted by Ashley Denmead: not to mention the increased drivability of a single!

Maybe you should mention it, what makes it easier to drive exactly?

Well, if you can floor it and the car doesn't spin, that's driveability!

Just kidding...

I think the lower weight (especially when coupled with other design choices) allows the tires to work better, so even with a lower power/weight ratio, a single car might be quicker. But, we'll find out about the tires in June, at least those teams that sign up for the testing will!

Ok if you havnt figured out what i meant by better drivability then i'll try and explain.

im sure were all aware of the circle of traction......

a single cylinder engine has one powerstroke for every 720degrees of crank rotation, where as a 4 cyl has a powerstroke every 180 degrees of crank rotation. with this in mind a four cylinder engine puts a forward moving force into the tyre 4 times as often as a single cylinder. Due to the tyre not being worked as often to produce forward motion there is more lateral grip available for cornering.

hope this explains what the heck i was on about earlier.

Another argument for singles is that some people believe they are more forgiving on driver error as they dont penalize the driver as much if the wrong gear is selected due to their low down torque and pulling power as compared to a high revving 4 cylinder 'Power engines'.

Anyway compromise is the name of the game......Just build the damn car and worry about making it go fast later haha

cheers

ash

Ash,

Excuse my ignorance but ...

I am having difficulty seeing how lowering the longitudinal loading frequency and increasing its amplitude increases lateral tyre loading capability.

Unforunately my knowledge of tyre frequency behaviour is pretty minimal. Did you pick this up from a reference or testing or is it more of a reasoned explanation?

I have heard a similar explanation from other people running singles and I am getting more and more curious as to where this theory cam from.

Kev

UWA Motorsport