crashcourse
XS650 Addict
First, let me say that I know that this proposed project would be very difficult and expensive, and that if I just wanted power I would be better off buying a new sportbike.
I've been reading a little about race teams that built custom heads to get better flow/combustion efficiency, etc. It made me think: what if you made a water cooled, 4 valve/cyl head for the xs650?
With smaller valves the rpm ceiling would go up, with increased cooling you could raise compression. More valve area means more air. Depending on head design, you could go to DOHC and play with valve timing and overlap. If you put in a big bore kit, there's another horsepower increase.
Now, because of the different head design, combustion speed would change, so we'll need adjustable timing. A beefier clutch to handle the extra HP would be a must. To further increase rpm ceiling, lighter pistons, lighter/stronger rods, and a balanced (and rephased) crank would also be in order.
Finish off with some exhaust and intake tuning, and some bigger carbs.
Of course this project would be massive, both in terms of expense and time. But what kind of power do ya'll think you could get out of a special construction engine like that? I think 100+HP wouldn't be a bad guess.
I've been reading a little about race teams that built custom heads to get better flow/combustion efficiency, etc. It made me think: what if you made a water cooled, 4 valve/cyl head for the xs650?
With smaller valves the rpm ceiling would go up, with increased cooling you could raise compression. More valve area means more air. Depending on head design, you could go to DOHC and play with valve timing and overlap. If you put in a big bore kit, there's another horsepower increase.
Now, because of the different head design, combustion speed would change, so we'll need adjustable timing. A beefier clutch to handle the extra HP would be a must. To further increase rpm ceiling, lighter pistons, lighter/stronger rods, and a balanced (and rephased) crank would also be in order.
Finish off with some exhaust and intake tuning, and some bigger carbs.
Of course this project would be massive, both in terms of expense and time. But what kind of power do ya'll think you could get out of a special construction engine like that? I think 100+HP wouldn't be a bad guess.
