Quote from Chrisuu01 :

Why?, I like it. But I suppose that is because I am not that well informed when in comes to engineering?

Which is why I think automation is perfectly suited to people who love technique but struggle with maths, people like me really.

Cam timing is far more complex than a 0-100 slider.

One of the main goals of valve timing is to manage the pressure waves generated by rapidly opening and closing valves. Proper valve timing generates a resonance at a particular RPM such that the design RPM is the most efficient. At this RPM, it's not just the piston falling that draws in air/fuel charge but also pressure waves in the intake tract. Likewise, exhaust gases are drawn out of the cylinder by pressure waves in the exhaust system.

SIDE NOTE: Two-strokes generally don't have any moving valves at all and rely upon an expansion chamber to generate resonant pressure waves at a particular RPM that reflect fresh charge that was drawn out the exhaust port and stuff it back into the cylinder. The expansion chamber is the bulbous part of many two-stroke exhaust systems and is effectively an acoustic supercharger. Its position in the exhaust pipe and overall shape (including length and width) determine the RPM at which resonance occurs.

Some of the specs used to identify cam timing are:
- lift (in units of distance), how far the valve opens into the cylinder
- duration (in degrees), the time the valve is open past a certain amount of lift
- centerline (in degrees) of the lift curve with respect to crankshaft rotation
- lobe separation (in degrees) between intake and exhaust centerlines

However, all of these specs merely attempt to represent a graph like this:



TDC (top dead center) and BDC (bottom dead center) refer to the position of the piston in its stroke (and the angle of the crankshaft).

There are also design considerations such as:
- do you want an interference engine, where the valves intrude upon the space swept by the piston? this means you can have more lift but it can also result in catastrophic engine failure if the cam centerline is sufficiently displaced in one direction or the other
- if you want a very fuel efficient engine, you don't want much valve overlap between intake and exhaust (i.e. both open at the same time), otherwise fuel can go in the intake port and straight out the exhaust port


All of this is implemented in Engine Analyzer. You can grab the free demo here:
http://performancetrends.com/Engine-Simulation.htm

Quote from Mr_Lonely :

i donno how many repairs i did, but just all of a sudden i was in a bigger garage.

22 i think it was when i got to the next one.

At your side note Forbin- Two strokes use expansion chambers (the bulbous part) to widen the powerband...you can use a straight pipe to achieve any frequency desired but the powerband will be narrow. A straight pipe that is the correct length/diameter for the port timing at a given RPM will produce more power than an expansion chamber that is designed to give power over a wider RPM range.

Quote from Anthoop :

At your side note Forbin- Two strokes use expansion chambers (the bulbous part) to widen the powerband...you can use a straight pipe to achieve any frequency desired but the powerband will be narrow. A straight pipe that is the correct length/diameter for the port timing at a given RPM will produce more power than an expansion chamber that is designed to give power over a wider RPM range.

I can't believe it would be more powerful without expansion chamber. And even if it is, it would be very shit to drive compared to correct length pipe with expansion chamber.

Quote from Anthoop :

you can use a straight pipe to achieve any frequency desired but the powerband will be narrow. A straight pipe that is the correct length/diameter for the port timing at a given RPM will produce more power than an expansion chamber that is designed to give power over a wider RPM range.

So, that's why all the F1 teams in the days of real F1 bikes used straight pipes ?

"Two strokes can function with up to 50% more power if they are aided in these 4 ways: 1) pulling in extra intake charge up from the crankcase into the cylinder, 2) pulling in extra intake charge from the carburetor into the crankcase, 3) preventing the intake charge from escaping through the exhaust port (so it can be used for combustion), 4) boosting the compression at top rpm for a faster burn and more power. An expansion chamber does just that. But at what part of the powerband it does it is dependent on how far from the engine the diffuser cone and baffle cone are. That is because the pressure wave (created when the exhaust suddenly enters the exhaust pipe) travels at a certain speed, so many meters per second. When the wave enters the diffuser cone the sudden expansion causes a reverse traveling suction wave which, when it arrives back at the cylinder matches the crankcase suction in order to prevent sucking exhaust gas from the cylinder into the transfers, and/or helps to pull up gasoline/air mixture from the crank into the cylinder. When the ongoing pressure wave in the pipe hits the baffle cone the sudden contraction of the wave causes a reverse pressure wave which, when it arrives back at the cylinder, prevents the escape of intake charge if the wave arrives between the time the piston closes the transfer ports and closes the exhaust port."
http://www.dragonfly75.com/motorbike/ECtheory.html

Quote from Racer X NZ :

So, that's why all the F1 teams in the days of real F1 bikes used straight pipes ?

Yes two stroke GP bikes "back in the day" used straight pipes....and before GP two strokes were used elsewhere too.
Personally though, those are not the "real F1 bikes" as you put it....men were men when it was a peaky 4 cylinder two stroke with around 150+BHP...and nasty tyres...they used expansion chambers.

Oh..and if you were challenging "A straight pipe that is the correct length/diameter for the port timing at a given RPM will produce more power than an expansion chamber "

You understand that the exhaust can enhance the engine performance..the engine will have a certain resonant frequency at which it produces the maximum power (on any certain day (temperature and air pressure are important))...if you set the exhaust length/diameter of a straight pipe then you will achieve a higher maximum output...but the RPM range the engine will operate in will be very narrow.
With expansion chambers you have the ability to increase exhaust timing whilst still having a useable engine.

Found this on a youtube video

It seems pretty clear the developer is quite the misogynist...

If you value your time, download Cheat Engine and set speedhack to x2 (or more if you can handle it).

Does that make the game less boring?

No. I find it too easy and it becomes boring quickly.