Build My Own Engine
 

Hi all. I have the opportunity to make my own engine as a project for a C.A.M. class that I am enrolled in. I was wondering if anyone knew when looking at the front of the flywheel while on the engine, wether the engines run clock-wise or counter-clock-wise. I plan on using a CNC machine for most of the work and making of the parts but just needed to know the direction the engines turn. Also on this question, How do I make sure it starts and runs the right direction. Thanks

Should start and run whatever direction you turn it with the pull start or starter box...I assume.

Ok I just wasnt sure because I have had engines run backwards and it doesnt work real well.

If this were another board I'd think you're trolling... ;D
Most nitro engines run clockwise, so looking at the flywheel from the front counter-clockwise.
The only directional part is the crankshaft as far as I know which is optimised for the direction it's running. They can run in both directions though, but will run much better in the correct one.
As for starting, you turn it into the right direction with a starter box, pullstart or some other contraption and you make sure it doesn't ignite too early which could lead to it turning in the other direction.
Is it just a CAD project or are you going to produce anything? If it's the latter then get some experience with existing engines first (10 years should suffice... ;D )

Ok, thanks for the info. First it is just going to be a CAD project but may grow into something more. We will see depending on if I can get it to work right.

Along this same line, is the different engine sizes, like .21 .28 .18 and so on, are these numbers the displacement of just the piston, or is it the piston sleeve con rod and crank?

Designing an engine that will run is rather easy. Just get any engine and reverse engineer it. The majority of today's .21 engines are all reverse-engineered off of each other and have become homogenized for the most part.

If you ever make it to prototyping, have a look at the early BP Racing engines. They used a 100% CNC'd engine case. This is basically going to be how you have to design your engine, as I doubt the school is willing to fund a diecast injection machine, and molds ($$$).
http://www.neobuggy.net/2006/11/01/1313/

The crankshaft timing is causing this. If the timing of opening and closing was symetric then the motor will run in both ways the same (based on glowplug ignition).

I have a list of timings on my website and also First-racing.eu has a large list, all based on engines running anti clockwise as seen from the front.
This is no problem to create, the biggest issue wiil be getting matching materials for the sleeve and piston. If the expansion do not match you can get a bad performing or even a bad running engine.

The website didnt work for me. Could you post a link? I would really like to try this

http://www.euronet.nl/users/tooms/timings/timings.htm

Direct link to my page about engine timings and on that there is a link to first racing.

Thanks.