The cam profile is specifically designed such that hot lash will be taken-up at a sensible velocity with both acceleration and jerk at minimum values - this ensures minimal impact forces at this juncture.
The valve-lift profile is therefore designed with specific lash ramp characteristics that...
BigVlad,
If you think any serious racing team, whether it be from F1, Inycar, NASCAR, LeMans Series, MotoGP, Superbikes, MX1...., I could go on ad infinitum, design their "engines off the shelf" then you are seriously wrong - they do it in-house and then get a reputable Cam Manufacturer/Grinder...
The students are being introduced to engineering science and analytical design techniques so that, as graduate professional engineers, they don't have to practise "trial and error", but instead will have the necessary skills and understanding to "optimise" a design problem and save time and...
The FSAE engine is usually a 600cc motorcycle engine taken from one of the sportsbikes - as you say. BUT the engine has a single 20mm restrictor in its intake ducting. You'll find that there are no "off-the-shelf" parts designed for this purpose, and anyway, this is a university design project...
Pedro,
You will see in the SAE paper I mentioned earlier that they were able to use the existing stock cams and get them reground. A reputable cam grinding shop will be able to regrind existing cams for about 200 pounds (at today's exchange rates that's equal to about 201 Euro!!!).
The fact...
There are several different file formats that are recognised by the most common standard types of cam grinding machines: .des, .opn, .cls, .s96, .p and .r files
As LarryCoyle pointed out, there is also the possibility of creating a 'master cam'. The machines that do this are: Berco, Storm...
Pedro, here's an FSAE paper that describes an FSAE project to redesign the camshaft to improve performance - might be of some interest:
www.sae.org/technical/papers/2008-32-0073
The coding of the MDOF is quite a challenge if you hope to model bounce, separation and clash within your simulation. I'd suggest using a Runge-Kutta approach to solving your MDOF system. Start with a simple system - no bounce, separation or clash - get this working with a robust solver and then...
How long have you got!? Taking on this type of project does not normally fall under the remit of a 'student project' - I don't mean you can't do it, but you'll probably find that you won't have the time or resources to do it right.
The commercial softwares you've mentioned (Valdyne, 4stHEAD...
Exhaust manufacturers still do the cut and try method at the latter stages of the development process, but up to this point they use one of the more robust 1D engine simulation codes to optimise designs:
GT-Power from Gamma Technologies
Wave from Ricardo
Boost from AVL
Virtual Engines from...
Greg's right, and if you can manage to get involved with the FSAE/Formula Student racing projects and gain relevant experience here - that seems to impress the F1 folks etc
Michael,
There is a forum that was set up a couple of years ago to try and do exactly what you have been talking about:
http://www.fourstrokedesign.com/forums/
This forum is primarily aimed at people using Optimum Power's Virtual Engines software - similar to the GT-Powers, Ricardo Waves and...
Try this book by Blair - plenty of empirical info/design guidlines in Chapt 6:
http://www.sae.org/servlets/productDetail?PROD_TYP=BOOK&PROD_CD=R-186
Most University libraries will have this book as it is very common and relevant to IC engine teaching/research.
Surprising noone else pointed...
Greg, I'm surprised you haven't CUT this post as there seems to have been an awful lot of "rubbish" posted (your words, not mine - I would have used something much stronger).
For anyone out there genuinely interested in truly understanding the "unsteady gas dynamics" effects that explain the...
I would recommend 4stHEAD. There are 3 main reasons for this:
1. Price - in relation to previous two examples.
2. I have it on good authority that it is being used very successfully in NASCAR, which is probably the most intense environment for a valtrain dynamics simulation.
3. Unlike the other...
