The Perfect FSAE Specific Engine

[Patrick W. Crane]

If you had the resources and the time, what type on engine would you design and build for the competition, would you use forced induction, and what would be your first choice for transmission? The Current top engine/transmission layout is just a four cylinder bike engine and the transmission that came with it, but as far as the ideal layout goes, it's pretty poor (high center of gravity and such).

Personally, I think an over square flat six turbo coupled to a custom five speed sequential transaxle would be my choice.

Easy to Balance and SMOOTH
Low center of gravity
Enough cylinders to avoid most of the pulsing effects
Short crankcase
Turbo to widen the power band (adds weight though and at high rpm it doesn't help as the air can't pass through the restrictor fast enough anyway... hmmm, maybe a bypass for high rpm...)

The only current custom engine I know of is the V8 by UWW (also what got me thinking about engines). I have to say, hats off to you guys - very impressive. I wish we had the facilities here at UVic to take on such an ambitious project. But who knows... maybe in 10 or 15 years a custom engine will be needed to stay competitive.

Comments?

[Richard Lewis]

Bah! Why reinvent the wheel?

Winston is obviously a Porsche fanatic, suggesting a flat 6.

Personally I really like the UWW layout, though I am not a big V8 fan. However, it does present a low CoG and many interesting advances. If I could do anything at all, I think I'd go with a small displacement 4 cylinder turbo, attached to a transaxle.

The reasoning is rather unscientific I'm afraid.
a) 4 pulses should get adequate flow through the restrictor, and spool the turbo nicely.
b) I think rotating inertia would become a bigger issue as you gain cylinders.
c) I love the transaxle idea as opposed to a tranny/chain driven differential.

In the end I think the real enemy isn't power, so much as weight and area under the torque curve. Cost may be an enemy too though.

Cool post, now go back to studying!

-------------------------
UVIC Formula SAE Team

http://uvic.fsae.ca

[gug]

Drysdale - 750cc v8, 19,000rmp!

oh how i wish we could run 750cc without a restrictor! and the small matter of an open checkbook might come in handy...

"I come from a land down under,
Where beer does flow and men chunder"

[Alfonso Ochoa]

I agree with richard. Small engine, like 400-450 cc, with a forced induction system, i would like a supercharger better.

Alfonso Ochoa Vega
cabezota311@hotmail.com
F-SAE USB Team, Venezuela

[Maxwell]

Freedom motors http://www.freedom-motors.com/ has a 530cc rotary engine with 110hp they use for baja cars (which get up to 43mph). Port it, turbocharge it and use an air to air intercooler. It would be infinately more complex than simply strapping a CBR on, but weight savings would be huge(in terms of the engine itself) with a completely different powercurve. The turbo could be almost directly attatched to the exhaust housing (simple packing). The size could allow placement closer to the center of gravity.

[Scott Wordley]

Yeah, a rotary would be cool, only problem is the engine has to be a four stroke.

I'm a big fan of the boxer idea though.

Regards,

Scott Wordley & Roan Lyddy Meaney
Monash FSAE Wingmen
http://www-personal.monash.edu.au/~fsae

[Maxwell]

Please forgive me- I am not on any FSAE team and am not aware of all restrictions. A rotary, however, is generally considered a 4-stroke by most engineering based companies. Mazda declared it's engine a 2-stroke because each rotor has only one intake and one exhaust stroke per revolution, as a two stroke does. BUT it has seperate intake, compression, power, and exhaust strokes.
Also, on a four-stroke there is 1 intake stroke per 2 revolutions, so if you look at it from a volumetric standpoint, displacement is the amount of combustion chamber volume inhaled over 2 revolutions. A rotary, with 1 intake stroke per revolution, must be measured as having 2 combustion chambers per rotor.
Can someone please tell me if the concept of a rotary is banned, or is it just the general 2-stroke notion?

[gug]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>
from the official rules
3.5.1.1) engine limitations
the engine used to power the car must be a 4-stroke piston engine with a displacement not exceeding 610cc per cycle. <HR></BLOCKQUOTE>
which sucks, cause rotarys rock. would probably help appeal to the sponsors too, a bit less mainstream, a bit more interesting.
personally, i would love to run a 2-stroke. i think suzuki made a factory turbo'd 500 that made 140hp or something?
i wonder how much it would affect the competition if the engine rules were removed? as it is we dont get too much time wide open throttle, i think without the restrictor some teams might actually go to smaller engines to reduce weight.
and some would go bigger too. west washington made a 600cc v8 with these rules, they would probably go for a 350 chev, "a real v8" if the rules werent there.

"I come from a land down under,
Where beer does flow and men chunder"

[Nam Tran]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> Can someone please tell me if the concept of a rotary is banned, or is it just the general 2-stroke notion? <HR></BLOCKQUOTE>

Rotaries are indeed banned. This is discussed in the 2003 Important Documents.

http://www.sae.org/students/fsae2003rules.doc

[MercerFSAE C. Burch]

Rotary power would be great for this competition but the rules state that the engine must be a "piston" powered engine. Rotaries do not have pistons. It isn't the 4 vs 2 stroke conflict that is the problem with the rules, it is the piston part that excludes the rotaries.

The other bad part about a rotary, were they to be allowed in this competition, is that a team would virtually have to build one from scratch. That pretty much excludes just about every team except for WWU.

From a technology point of view, it is like banning a better technology for the sake of the more common and well-known technology. Similar to forcing cars to used grooved tires instead of slicks.

Chris
Mercer University Drive!
Coming to an Auto-X near you, May 2004!