Ill agree the intercooling is an advantage but even an efficient air-air (air-water not really feasible for FSAE) intercooler only cools to about ambient, which a N/A motor breathes anyways... Basically only makes up for the compressor inefficiencies.

The worse (more radical) idea does involve an architecture with one big American piston but now take that idea and pare as many pieces and parts off the design as possible. Think about possibly adding forced induction and really take the design simplification seriously and you're nearly there...

I have no idea if it will rattle itself to death though.

Matthew

This message has been edited. Last edited by: Matt N,

Just to get the haters going out there...

Too bad no nitrous oxide. Combine a big antique american single with the brown go kart described in the other thread and a little shot of juice, and you would really piss some people off at comp, and not because it was slow and ugly - but because it was fast and ugly...

Matthew

Matt,

Re: "worse (more radical) idea"

I've thought hard about this, over a coffee...

So, start with big American piston and add as little as necessary. Conrod and crank are simplest way I know of converting reciprocating piston motion to necessary rotating wheel motion. So no swash-plates, scotch yokes, fancy cams, etc.? But, maybe just a half-crank? This was my original idea on the earlier post (p4), using roller bearings and splash lubriction. But the full-crank, plain bearings, and normal oil pump, are possibly just as easy, or easier?

Maybe a flat-head? The low revs and S/C make this feasible. Still need a half speed cam drive, but it makes a more compact package than OHV (most complicated) or SOHC (quite simple with a rubber belt drive).

Maybe direct drive - ie. wheel axles direct to either side of the (full) crank? But this means two sets of clutches and neutral dogs. Besides, even with a S/C the engine would need about 4:1 overall gear ratio. So cancel that.

Do we need the primary balance shafts? Not really, I was just showboating. EFI? A good carb might do (though EFI's are also simple)?

So what's left? A 600cc Briggs & Stratton, with optional supercharging!!! (I heard that at about ~350cc(?) N/A they make ~35hp in those junior drag cars.)


Z

This message has been edited. Last edited by: Z,

Matt,
check out our setup in the high school sae car.
We think alike.
Bryan

quote:

Originally posted by Matt N:
Just to get the haters going out there...

Too bad no nitrous oxide. Combine a big antique american single with the brown go kart described in the other thread and a little shot of juice, and you would really piss some people off at comp, and not because it was slow and ugly - but because it was fast and ugly...

Matthew

Matt N
[Ill agree the intercooling is an advantage but even an efficient air-air (air-water not really feasible for FSAE) intercooler only cools to about ambient, which a N/A motor breathes anyways... Basically only makes up for the compressor inefficiencies.]

Only...if an intercooler can do that you now have air at much higher density then an NA engine and you can run it at the same high (efficient) compression ratios. It actually more then makes up for compressor inefficiency cause even 100% efficient compression heats the charge a significant amount.
It's free horsepower, although there are other faults. An intercooler has weight, requires air passing over it to remain efficient, which means car speed effects engine tune. This can be fixed by an equally heavy fan. An intercooler also has volume, which hurts throttle response on a FSAE system. And finally, it has a pressure drop, which is a pumping loss that will lower peak hp on a restricted engine, although average hp will be considerably higher.

I know it has been mentioned before, but E85 works like an intercooler without the weight, volume or pressure drop drawbacks.

has anyone considered sleeving or destroking one of the new Honda XR-650's that've been dominating in the baja races lately (last i checked at least)? being a larger motor, though it is a little heavier than the ~450 motocross bikes, it probably has a beefier transmission and clutch, and as a whole the motor would be running at closer to its designed power level. this would be a similar strategy to the 660 raptor motor...

So guys, what's the verdict on an electric start system for the yz450? I've been looking around and can't make up my mind. For those who know about this engine, how much work is involved? More importantly - how much money is involved? Do you think it's worth it?

If I remember correctly since the last time I was at a dealer, the ATV's running that engine have a factory setup. I'm not sure if it would bolt up, but that may be a good place to start.

just found a husqvarna that has a 576cc single, the TE 610: Dual Sport.

It may work well if you can find one.

Thoughts?

Holy shit, Dave, that is a big chainsaw!!
But really, does anyone sell the Husky? And what is the availability? I have talked to some supermoto guys and they say the only guys rding them are the factory dudes. It might be easier to get an aprilia twin. Anyway, good luck with the fight for better power (notice that I didn't say more).
Bill Kunst

I'm using a YFZ450. Anybody have any single-cylinder Noise Test troubles? Any advice on specific mufflers to look at and/or to avoid? Anybody make their own...and how'd u do it?!
-Dave

The Cannondale 440 sounds tempting. Its cylinder is oriented vertically, takes in air from the front and exhausts it out the back, which is the opposite of most bike engines. It seems like this would make for a very favorable packaging situation, especially if you were worried about wrench access to a turbo. Any thoughts?

quote:

Originally posted by Ecks:
The Cannondale 440 sounds tempting. Its cylinder is oriented vertically, takes in air from the front and exhausts it out the back, which is the opposite of most bike engines. It seems like this would make for a very favorable packaging situation, especially if you were worried about wrench access to a turbo. Any thoughts?

One thought Ecks, dont turbo a single....

The Cannondale 440 is a very tempting engine; in fact we're using it for the second time this year. It produces good power per weight, it's fuel injected, has a dry sump, and appears to be ideal for a lightweight FSAE car. But it is unreliable. The engine had problems when it was in production and these problems were never fixed because Cannondale decided to drop their motorcycle/ATV line. Also, since the engine was only produced for a few years, they are limited in supply and parts are hard to come by. ATK does service on these engines and sells rebuilt engines that have a "reliability kit" installed, but even those engines have problems.

We've really wanted the Cannondale 440 to work for us, but I don't doubt that we will be moving to another engine next year.

And yes, singles are noisy. The Cannondale 440 has dual exhaust ports which we ran out to dual mufflers pointed in different directions (each outlet is measured individually). It ended up being unbearably loud at the competition and we actually had to be retested for noise after the endurance race because of complaints from the flaggers. We still had no problems passing the noise test though.

I am going to throw this out there again just as I am telling my guys to do next year after I leave. Jawa 500 with a cvt. Modify it to carry extra oil, built a duct with an electic fan for cooling and run alcohol and utilize the 16:1 compression it comes with if they can get away with it. Put a starter ring gear on the cvt stationary pully ala snowmobiles. For you IRS guys lean the engine 30 degrees off vertical toward the rear of the car and put the diff right under the cylinder. Run the cvt toward the firewall and hold the secondary with bearing blocks then run the chain BETWEEN the cvt and the engine block which allows you to run a torsen and mount the sprocket spaced off the ring gear flange a couple inches and you have equal length driveshafts. Firewall to rear axle center line will end up right at 12" center to center. Dont know if you guys ahve ever seen speedway bike racing but the things are fast and engines are reliable. I have been talking to the guys at jawa and they seemed to be real excited with the possibility of jawa powered formula sae. More of a matter of who gets to them first. Use the cvt we are using this year and you can package this thing so tight it would make your head spin. Driving a cvt the thing would intake on the firewall side and exhaust out the back. Stock power is 70hp on meth and i image 50hp would be easy to get. If that isnt enough for you guys remember that Cal Poly Slo finished 13th overall in west on 21hp and Dearborn finish 30th and 31st on 7 and 13hp.

http://www.jawa.cz/

We urgently need CAD model and manual of Yamaha WR 450.
Please mail me at dcemech89@gmail.com

This message has been edited. Last edited by: Rev Hard,

Anyone noticed these yet?

565.5cc
Linky: Husaberg FE570

Certainly challenging the traditional motorcycle engine configuration. Probably too rare for use in FSAE. Thoughts?

It seems like CG would be prohibitively high on that motor, at least in the stock orientation.

Though packaging might be easier.

The output shaft runs in reverse due to the engine orientation in the bike...

From the website: "Compact and light construction with an extremly low center of gravity "

I dont see how it could have a lower centre of gravity when its tilted up on its side...

Maybe they did it just to be different

On a bike you want the mass as close as possible to the line between the contact patch of the rear wheel and the steering head. Because the bike rotates around this line when turning a corner.