deciding on what engine to run

[edstrokedta]

hello, my name is ed. i am a student at uab in mechanical engineering. i am starting my ssenior design project this summer and i am loking for any help that i can get. i am in charge of the engine design for the formula car. i was told that we needed more power to be a competitor. we are currently running a crf450 dirt bike engine, but it just would not cut it at the competition. so any ideas on what engine combinations work best? i have heard that turboing the car is an option, but any info would help greatly.

ed

[murpia]

Go on, be an engineer, you know you want to...

Engineers analyse problems using the tools of physics, mathematics and common sense. Then they propose solutions for peer review with a series of pros and cons, and a consensus is reached. At least, that was what I was taught in the years before the internet...

Regards, Ian

[VFR750R]

Hint: If your car was slow, it likely wasn't the engines fault.

Hint 2: Search this forum, there is days of engine information/opinion here already.

[drivetrainUW-Platt]

There is nothing wrong with a 450 dirtbike engine.

[BeaverGuy]

While I certainly Agree with Ian and VFR750's sentiments I'm going to answer this anyway. More because it is an overal design approach question than anything else.

The engine that is best is dependent on what your design goals are. Those design goals should really be the first thing that you lay out and I'm not talking about a goal saying "Win the competition." Though that may be on of the goals it isn't the most important when it comes to selecting an engine or chassis style. The goals should be things you can stick on a house of Quality as customer requirements and then boiled down into engineering requirements. It is when you decide on what the balance between these goals is that you can decide on what engine, chassis, or suspension design to use.

That being said, if you were to look at the winners of the past five competitions in the US, which is only the last 2+ years. You would find a turbocharged 600 4cyl, a Naturaly aspirated 450 dirt bike motor, a Supercharged 450 dirtbike motor, a naturally aspirated 600 4cyl, and a naturally aspirated twin cylinder. So it clearly doesn't matter what the engine selected is, only that it meshes with your overall design goals and its intergration with the car is well executed.

[drivetrainUW-Platt]

Or an inline 3 cylinder...

[Gruntguru]

Hey DTUW-P. What are the options for in line 3 cyls? Google search doesn't help much.

[The AFX Master]

Mahle did a inline 3 suited for F-SAE on 2007, Here is a thread of an university struggling to get the car ready before 07 comp.. they did within hours of tech i think.

[CSULA Reid]

For our team we started with what we know from the competition and the rule restrictions. Then figured what we wanted from the engine and came up with some possible engines. From that we chose the best one for us.

Also remember that the drivetrain selection and design can also play a big role. If you have all the power in the world and can't get it to the ground and use it, what is the point.

If I where you, I would look at the whole engine and drivetrain that you currenly have to see where the problem is. I don't think that that engine that you currently have is a bad choice.

[AxelRipper]

Originally posted by The AFX Master:
Mahle did a inline 3 suited for F-SAE on 2007, Here is a thread of an university struggling to get the car ready before 07 comp.. they did within hours of tech i think.

that would have been us... the lovely show piece is sitting in the corner of the shop now... bearings gave out at comp because we had no testing time... the tank of an engine arrived at the shop in MI less than a week before comp... then we lost the sponsorship and the ECU/all support for the motor.