Raptor: SOHC
Z400: DOHC

Who's the *&#@ing retard who decided that 2 over head cam shafts was better than 1?

me thinks someone needs to be sent back to school to take dynamics again.

 

no engineering geeks here?

*sigh*

 

But why 2 carbs? Most people have ahard enought time trying to tuning one.
Each quad will have some good and then some bad points. Some more, some less.

 

The raptor has 2 carbs???

Well, with 3 intake valves it would definitely make the A/F mixture intake charge more consistent.

 

Why two cams? Direct valve acutation - in other words, no rocker arms. Less mass to control at higher RPMs.

Who's the *&#@ing retard who decided that 2 over head cam shafts was better than 1?

I guess they decided to go with 2 cams for the same reasons the *&#@ing retard who designed the YZ426F engine did.


The raptor has 2 carbs???

Well, with 3 intake valves it would definitely make the A/F mixture intake charge more consistent.

How? One carb feeds one valve, the other feeds two - nothing consistant about that - very questionable design.

CC for CC, stock for stock the Z400 develops more power than the Raptor. They must have done something right.

 

the two carbs don't feed all 3 valves at the same time? That is really weird.

 

Two carbs are used in order to keep the intake charge at a higher velocity during low RPM operation than would be possible with one large carb. High velocity airflow through the intake runners helps with throttle response and low-end torque, while still delivering enough airflow volume for top end. Actually a pretty good design. The same idea behind dual intake runners on some Hi-performance cars.