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?

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

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"

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

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.

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

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?

quote:

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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.

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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"

quote:

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Can someone please tell me if the concept of a rotary is banned, or is it just the general 2-stroke notion?

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

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

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!

quote:

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Originally posted by MercerFSAE C. Burch:

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.

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im assuming that you mean there is no mass produced rotary that is small enough? the power source in those twin bladed military choppers, the big ones used for transport (sorry i cant remember the name) is a 90hp rotary. they are for sale from somewhere in the states, weigh about 20kgs i think. anyway, designed to run at constant speed (of 80,000 rpm i think) and take a week to get there, but combining that with a cvt would produce an excellent car.
seen one go bang before though, i wouldnt want to be trying to fix it. the things dont just start running badly, its 80,000rmp to 0 instantly. it was being used as a power source on some geophysical instruments.
if anyone can fill in the gaps in my memory here you are welcome to.

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

gug,

I think that you are talking about a turbine. Everyone else is talking about a Wankel Rotary.

James Waltman
waltmaj@cc.wwu.edu
http://dot.etec.wwu.edu/fsae/
Formula SAE
Vehicle Research Institute at
Western Washington University

Yea, I am pretty sure he is talking about the Chinook helicopter built by Boeing. As far as I know it has a couple of 1,000HP+ turbines in it. I think unlimited hydroplanes use them for power. Don't think they would work for an FSAE car

University of Washington
Formula SAE 2001-2003

I'm sure he's talking about the electric power source/APU, which is indeed a small gas turbine, not a Wankel.

http://www.gasturbine.pwp.blueyonder.co.uk/solar.htm

They're pretty cheap to buy but getting that thing to propel an FSAE would be a different story altogether.

I dunno guys, do you think we could finally get the air to go supersonic through the restrictor if it was being pulled by a turbine engine?
Anyway I believe that a better engine can be made for this competition. I'm still wondering what design would be better- a small bore, long stroke, lower rev, forced induction, with a wide ratio tranny, or a small displacement high winding engine tuned around the restrictor?

The D model Chinook has two 3,500 (4,500 emergency) horsepower gas turbines and the T62 apu gas turbine linked by Marc. The T62 in the Chinook weighs about 70 pounds and puts out 65 horsepower. They are obscenely loud and guzzle JP-4 (diesel fuel for all intents and purposes). If you are in the US Army starting the T62 (necessary for stating the main engines) requires pressurizing a 3,500-psi hydraulic accumulator BY HAND PUMP. If you are an Aussie, you press a little button and an electric motor pumps it up for you (unless you left the battery plugged in and then you get to pump by hand Any one who appreciates mechanical things owes to themselves the spectacle of a Chinook run-up. If you can get a ride in one even better! I was a Chinook Flight Engineer in the US Army for four years. If you want to know anything else about these beasts let me know.

Rich

aka dr(CH)47(D)watson

cheers ppl, that is exactly what i was talking about. sorry for trying to call it a wankel rotary, no more late night posts for me.

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

Now that the thread has encompassed turbine engines, ho long before someone tries a compound ? Pratt and Whitney did this in the years just before the Jet age. (Lockheed Constellation was one application) The idea is to harness the spare grunt developed in the turbocharger and gear it back into the crankshaft.
I seem to recall that in the days of the turbo 1.5 litre Formula One, Keith Duckworth proposed a compound engine to the FIA. The formula had generated monster engines with more than 1000 HP in qualifying trim from straightforward turbo engines, yet here was Duckworth suggesting a loophole in the rules that would develop MUCH more power, especially with extra fuel dumped into the exhaust. Blanching at the idea of a 2,500 HP engine in a 1200lb car, the FIA promptly nixed that idea and Turbo engines in general soon after.
Just a thought =]
Pat D'Rat

Rudeness is a weak mans imitation of strength

quote:

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Originally posted by Suddenlee:
Now that the thread has encompassed turbine engines, ho long before someone tries a compound?

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its a bit vauge, but i think a compund engine is outlawed by the rules right? "The engine used to power the car must be a four-stroke piston engine..."
you are wondering when someone will try it in f-sae right?

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

Gug, when you get to know me better, you will recognise when a little leg pulling is happening =]
Pat

Rudeness is a weak mans imitation of strength