4-strokes 600 cc and smaller

Discussion in 'Technical' started by im devestatingly handsom, Feb 16, 2008.

  1. If anyone knows of any good power:weight ratio engines please post the information here. We are looking into doing an engine change for FSAE soon and are doing research on possible choices.

    We are using the Honda F4i, and are looking at the Aprillia SXV 550 along with as many others as we can.

    If anyone has any suggestions please let me know.
  2. I'm betting you're on the right track with motorcycle engines, but I don't have any recommendations.
  3. I know theres a 600cc yamaha motorcycle engine thats been used successfully in a couple canadian FSAE cars.
  4. Yamaha & Suzuki tend to be class leaders for HP
  5. Hp wise a 600cc sport bike engine is going to be the highest, but the ktm 530 525 or 520 thumpers would probably be great engines for somthing very light.
  6. My uni uses an R6 engine.
  7. some teams use like single cyl motors with alot of success due to horrendous amounts of torque.

    F4is are what we use though. it works well.
  8. The Aprillia seems like the latest rage in FSAE
  9. #10 im devestatingly handsom, Feb 17, 2008
    Last edited by a moderator: Apr 25, 2016
    has anyone heard of the Maxsym gp500 or gp600? i came across it and it sounds amazing except for the $10,000 price.

    gp500 (stock)
    110 bhp
    45 torque
    35 kg (dry)

    gp600 (stock)
    80 bhp
    55 torque
    35 kg (dry)

  10. It should also be said that a tricked out cr500 2 stroke would kick ass, not to mention badass.
  11. I cant really think of a reason to get another motor other than an F4i. Its much better to revise a design than to try to reinvent the wheel in FSAE. The cars are not power limited in any way, so a good tune will be more handy than a new motor. Lowering the number of variables to change is mega important.
  12. There isn't a hp limit, but there is the restrictor to deal with limiting airflow therefore curbing your ability to make power at higher engine speeds.

    In FSAE people run quite a wide array of engines that are out on the market. There is the common 600cc 4-cyl motorcycle engine. Teams have also run twins (U of M Dearborn used a freakin Briggs!) and singles. Then there is the question of whether to tune the engine normally aspirated or with forced induction.

    Our school used Honda F4/F4i's in the past. Last car had the Mahle 609cc 3-cyl engine, but that program is done now. Our next car will have a single cylinder engine. It really all depends on your concerns for your design. Are you more concerned with power or weight? What about packaging? Cost?

    If you are doing FSAE and studying engineering I would hope you could figure out the engine that best compromises what you want out of the package. That is engineering after all.
  13. The engines must be four stroke so that nixes that idea.
  14. thats lame.
  15. #16 VeNoM, Feb 18, 2008
    Last edited by a moderator: Apr 25, 2016
    Not really. The only formula car class that uses 2-strokes that I know of is SCCA Formula 500 so it seems logical.

    FSAE is a development series for future race engineers, so why allow a type of engine not used in any series that they would be working in. With a displacement cap of 610cc and the restrictor (20mm with gasoline; 19mm with E85) the engine regs are still pretty open as to what you can try.

    Rules for FSAE can be found here if anyone is interested:
  16. Motorcycle engines of course, I think the local Uni FSAE team uses a Kawa 600cc, it would be neat to create an entirely road legal version of such a vehicle. Motorcycle engines are great at making power with such a small size.
  17. My personal opinion after going through it is that any of the 600cc sport bike engines should give you enough power (especially if you turbocharge it), so I would focus on lighter weight and gearing. When I was at the race in Pontiac back in 2001, there was really no way that you were going to be able to hit more than about 80 mph on the autocross/endurance course, so adjust your final drive ratio as appropriate. My team used a turbocharged single-cylinder from a Buell Blast (492 cc) that after the younger kids blew it up went up to a bit over 500 cc in the rebuild. The engine was producing 100 hp and 90 lb-ft (at the rear wheels IIRC.... I graduated before the car was completely finished) before the competition and then the turbo crapped out. Although we would have had more power and by far more torque than anyone else at the event that year if the turbo hadn't failed, the Buell engine and transmission were heavy and along with some other choices made the car weigh a little over 800 lb. where most of the competitive teams were closer to 400 lb. and the vast majority of all the other cars were below 500 lb. So, our car may have ended up not being all that competitive even with the most power and torque.
  18. im fully aware of what FSAE is. Im on the texas team.

    I was just saying its usually more beneficial to tune somehting well than to try to reinvent the wheel. A well optomized set of leaf springs will almost always outpreform a poorly set up fancy system.

    This is especially true with motors in FSAE because the cars are so not-power dependant. A good driver with a 40hp car will obliterate most of the teams running 90 hp. Hell, I wouldnt be surprised if alot of teams ended up being FASTER with less power, simply because the cars would be much easier to drive.

    I would think there are far larger gains to be made in keeping a known motor with a tune youve already got and putting all of the time, effort, and money into other parts on the car. Especially if it means getting the car done sooner for more test time.

    THAT is engineering. Remember to factor in time, workability, cost and all of those other things. Its not just about the best compromised product for the application.
  19. I didnt know it could be turbocharged. In that case a turbocharged big bore thumper would be amazing.
  20. reliability of a thumper may come into question
  21. Also if you are looking for light look into aircraft engines.
  22. Quote from phanofmuzik2
    A good driver with a 40hp car will obliterate most of the teams running 90 hp. Hell, I wouldnt be surprised if alot of teams ended up being FASTER with less power, simply because the cars would be much easier to drive.

    I have to agree! I have seen it happen many times.
  23. It prob wasn't clear, but only the first line was in response to your statement so that people would know that there are some regs in place to limit power output, but no hard cap.

    The rest was just to give some insight to those members who don't know the FSAE rules at all. I agree with everything you said here.

    Our Mahle-powered '07 car is a perfect example of the opposite situation and why the way of doing things you stated is really the way to go IMO as well. We switched from out tried and true F4 lineage to the unproven Mahle powertrain. The car minus the drivetrain was probably the best thing Kettering FSAE has produced. The fabrication was very well done. With a significantly heavier drivetrain, we still lopped ~15 lbs off the wet weight of the car. The decision to switch to the Mahle led to many of the problems you speak of avoiding by doing things the way you mentioned.

    Now Mahle has ended its FSAE engine program. The engine is basically only good for about 20 hours more of run time and we have no MoTeC M800 ECU since it was a Mahle loaner. We may try to get the fuel map to work with a MicroSquirt and we have spark figured out already. However that car is going to be a show/demo car only.

    Our next car, like I said earlier in the thread, will be using a thumper with weight savings being the major goal for the 2009 car.

    Which U of T campus are you on?
  24. university of texas at austin.

    the founders of FSAE :p

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